Microchip CAP1298 8-channel capacitive touch sensor controller with proximity detection & signal guard Datasheet

CAP1298
8-Channel Capacitive Touch Sensor Controller with
Proximity Detection & Signal Guard
General Description
Applications
The CAP1298 is a multiple channel capacitive touch
sensor controller. It contains eight (8) individual capacitive touch sensor inputs with programmable sensitivity
for use in touch sensor applications. Each sensor input
is calibrated to compensate for system parasitic capacitance and automatically recalibrated to compensate
for gradual environmental changes.
•
•
•
•
In addition, the CAP1298 can be configured to detect
proximity on one or more channels with an optional signal guard to reduce noise sensitivity and to isolate the
proximity antenna from nearby conductive surfaces
that would otherwise attenuate the e-field.
• Eight (8) Capacitive Touch Sensor Inputs
- Programmable sensitivity
- Automatic recalibration
- Calibrates for parasitic capacitance
- Individual thresholds for each button
• Proximity Detection
• Signal Guard
- Isolates the proximity antenna from attenuation
- Reduces system noise sensitivity effects on
inputs
• Multiple Button Pattern Detection
• Power Button Support
• Press and Hold Feature for Volume-like Applications
• 3.3V or 5V Supply
• Analog Filtering for System Noise Sources
• RF Detection and Avoidance Filters
• Digital EMI Blocker
• 8kV ESD Rating on All Pins (HBM)
• Low Power Operation
- 5µA quiescent current in Deep Sleep
- 50µA quiescent current in Standby (1 sensor
input monitored)
- Samples one or more channels in Standby
• SMBus / I2C Compliant Communication Interface
• Available in a 16-pin 3mm x 3mm QFN RoHS
compliant package
• Available in a 14-pin SOIC RoHS compliant package
The CAP1298 includes Multiple Pattern Touch recognition that allows the user to select a specific set of buttons to be touched simultaneously. If this pattern is
detected, a status bit is set and an interrupt is generated.
The CAP1298 has Active and Standby states, each
with its own sensor input configuration controls. The
Combo state allows a combination of sensor input controls to be used which enables one or more sensor
inputs to operate as buttons while another sensor input
is operating as a proximity detector. Power consumption in the Standby and Combo states is dependent on
the number of sensor inputs enabled as well as averaging, sampling time, and cycle time. Deep Sleep is the
lowest power state available, drawing 5µA (typical) of
current. In this state, no sensor inputs are active, and
communications will wake the device.
 2013-2015 Microchip Technology Inc.
Desktop and Notebook PCs
LCD Monitors
Consumer Electronics
Appliances
Features
DS00001571B-page 1
CAP1298
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DS00001571B-page 2
 2013-2015 Microchip Technology Inc.
CAP1298
Table of Contents
1.0 Introduction ..................................................................................................................................................................................... 4
2.0 Pin Description and Configuration .................................................................................................................................................. 8
3.0 Functional Description .................................................................................................................................................................. 21
4.0 Register Descriptions .................................................................................................................................................................... 58
5.0 Operational Characteristics ........................................................................................................................................................... 69
6.0 Package Outline ............................................................................................................................................................................ 85
Appendix A: Data Sheet Revision History ........................................................................................................................................... 91
The Microchip Web Site ...................................................................................................................................................................... 93
Customer Change Notification Service ............................................................................................................................................... 93
Customer Support ............................................................................................................................................................................... 93
Product Identification System ............................................................................................................................................................. 94
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DS00001571B-page 3
CAP1298
1.0
INTRODUCTION
1.1
Block Diagram
FIGURE 1-1:
CAP1298 BLOCK DIAGRAM
VDD
GND
SMCLK
CS5 /
SG
SMBus
Protocol
Capacitive Touch Sensing Algorithm
SMDATA
ALERT#
CS1
CS3
CS4
CS6
CS7
CS8
Pin Diagrams
FIGURE 1-2:
CAP1298 14-PIN SOIC
CS2
1
CS1
CS3
2
14
13
ALERT# 3
12
CS5/SG
11
CS6
10
CS7
9
CS8
8
GND
SMDAT
4
SMCLK
5
N/C 6
VDD 7
DS00001571B-page 4
CAP1298
1.2
CS2
CS4
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CAP1298
ALERT#
1
SMDATA
2
CS1
CS2
CS3
CS4
15
14
13
CAP1298 PIN DIAGRAM (16-PIN QFN)
16
FIGURE 1-3:
12
CS5 / SG
11
CS6
Exposed pad
1.3
8
CS8
GND
9
7
4
GND
VDD
6
CS7
N/C
10
5
3
N/C
SMCLK
Pin Description
TABLE 1-1:
PIN DESCRIPTION FOR CAP1298
QFN Pin
#
SOIC Pin #
Pin Name
1
3
ALERT#
ALERT# - Active low alert / interrupt output for SMBus alert
2
4
SMDATA
3
5
SMCLK
4
7
VDD
5
6
N/C
6
-
N/C
7
8
GND
8
-
GND
9
9
CS8
10
10
CS7
 2013-2015 Microchip Technology Inc.
Pin Type
Unused
Connection
OD
Connect to
Ground
SMDATA - Bi-directional, open-drain
SMBus or I2C data - requires pull-up
resistor
DIOD
n/a
SMCLK - SMBus or I2C clock input requires pull-up resistor
DI
n/a
Power
n/a
n/a
Connect to
Ground
n/a
Connect to
Ground
Ground
Power
n/a
Ground
Power
n/a
AIO
Connect to
Ground
AIO
Connect to
Ground
Pin Function
Positive Power supply
Not internally connected
Not internally connected
Capacitive Touch Sensor Input 8
Capacitive Touch Sensor Input 7
DS00001571B-page 5
CAP1298
TABLE 1-1:
PIN DESCRIPTION FOR CAP1298 (CONTINUED)
QFN Pin
#
SOIC Pin #
Pin Name
11
11
CS6
Pin Function
Pin Type
Unused
Connection
AIO
Connect to
Ground
AIO
Connect to
Ground
AIO
Leave Open
AIO
Connect to
Ground
AIO
Connect to
Ground
AIO
Connect to
Ground
AIO
Connect to
Ground
-
-
Capacitive Touch Sensor Input 6
CS5 - Capacitive Touch Sensor Input 5
12
12
CS5 / SG
SG - Signal Guard Output
13
13
CS4
14
14
CS3
15
1
CS2
16
2
CS1
Bottom
pad
-
Exposed
pad
Capacitive Touch Sensor Input 4
Capacitive Touch Sensor Input 3
Capacitive Touch Sensor Input 2
Capacitive Touch Sensor Input 1
Not internally connected, but recommend
grounding
APPLICATION NOTE: All digital pins are 5V tolerant pins.
The pin types are described in Table 1-2, "Pin Types".
TABLE 1-2:
PIN TYPES
Pin Type
Power
DI
AIO
DIOD
OD
DS00001571B-page 6
Description
This pin is used to supply power or ground to the device.
Digital Input - This pin is used as a digital input. This pin is 5V tolerant.
Analog Input / Output - This pin is used as an I/O for analog signals.
Digital Input / Open Drain Output - This pin is used as a digital I/O. When it is used as an
output, it is open drain and requires a pull-up resistor. This pin is 5V tolerant.
Open Drain Digital Output - This pin is used as a digital output. It is open drain and requires
a pull-up resistor. This pin is 5V tolerant.
 2013-2015 Microchip Technology Inc.
CAP1298
2.0
ELECTRICAL SPECIFICATIONS
TABLE 2-1:
ABSOLUTE MAXIMUM RATINGS
Voltage on VDD pin
-0.3 to 6.5
V
Voltage on CS pins to GND
-0.3 to 4.0
V
Voltage on 5V tolerant pins (V5VT_PIN)
-0.3 to 5.5
V
Voltage on 5V tolerant pins (|V5VT_PIN - VDD|) (see Note 2-2)
0 to 3.6
V
Input current to any pin except VDD
+10
mA
Output short circuit current
Continuous
N/A
Package Power Dissipation up to TA = 85°C for 16-pin QFN
(see Note 2-3)
0.5
W
Junction to Ambient (JA) (see Note 2-4)
70
°C/W
Operating Ambient Temperature Range
-40 to 125
°C
Storage Temperature Range
-55 to 150
°C
ESD Rating, All Pins, HBM
8000
V
Note 2-1
Stresses above those listed could cause permanent damage to the device. This is a stress rating
only and functional operation of the device at any other condition above those indicated in the
operation sections of this specification is not implied.
Note 2-2
For the 5V tolerant pins that have a pull-up resistor, the voltage difference between V5VT_PIN and VDD
must never exceed 3.6V.
Note 2-3
The Package Power Dissipation specification assumes a recommended thermal via design consisting
of a 2x2 matrix of 0.3mm (12mil) vias at 1.0mm pitch connected to the ground plane with a 1.6 x
1.6mm thermal landing.
Note 2-4
Junction to Ambient (JA) is dependent on the design of the thermal vias. Without thermal vias and
a thermal landing, the JA will be higher.
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DS00001571B-page 7
CAP1298
TABLE 2-1:
ELECTRICAL SPECIFICATIONS
VDD = 3V to 5.5V, TA = 0°C to 85°C, all Typical values at TA = 25°C unless otherwise noted.
Characteristic
Symbol
Min
Typ
Max
Unit
Conditions
DC Power
Supply Voltage
VDD
3.0
5.5
V
µA
Standby state active
1 sensor input monitored
Default conditions (8 avg, 70ms
cycle time)
µA
Standby state active
1 sensor input monitored
1 avg, 140ms cycle time
Supply Current
ISTBY_DEF
120
ISTBY_LP
50
170
IDSLEEP_3V
5
TBD
µA
Deep Sleep state active
No communications
TA < 40°C
3.135 < VDD < 3.465V
IDD
500
750
µA
Capacitive Sensing Active
signal guard disabled
Capacitive Touch Sensor Inputs
Maximum Base
Capacitance
CBASE
Minimum Detectable
Capacitive Shift
CTOUCH
20
Recommended Cap
Shift
CTOUCH
0.1
Power Supply
Rejection
50
PSR
2
±3
±10
pF
Pad untouched
fF
Pad touched - default conditions
pF
Pad touched - Not tested
counts
/V
Untouched Current Counts
Base Capacitance 5pF - 50pF
Negative Delta Counts disabled
Maximum sensitivity
All other parameters default
Power-On and Brown-out Reset (see Section 4.2, "Reset")
Power-On Reset
Voltage
VPOR
1
Power-On Reset
Release Voltage
VPORR
Brown-Out Reset
VBOR
VDD Rise Rate
(ensures internal
POR signal)
SVDD
Power-Up Timer
Period
tPWRT
Brown-Out Reset
Voltage Delay
tBORDC
DS00001571B-page 8
V
Pin States Defined
2.85
V
Rising VDD
Ensured by design
2.8
V
Falling VDD
V/ms
0 to 3V in 60ms
0.05
10
1
1.3
ms
µs
VDD = VBOR - 1
 2013-2015 Microchip Technology Inc.
CAP1298
TABLE 2-1:
ELECTRICAL SPECIFICATIONS (CONTINUED)
VDD = 3V to 5.5V, TA = 0°C to 85°C, all Typical values at TA = 25°C unless otherwise noted.
Characteristic
Symbol
Min
Typ
Max
Unit
Conditions
15
ms
200
ms
0.4
V
ISINK_IO = 8mA
ISOURCE_IO = 8mA
Timing
Time to
Communications
Ready
tCOMM_DLY
Time to First
Conversion Ready
tCONV_DLY
170
I/O Pins
Output Low Voltage
VOL
Output High Voltage
VOH
VDD 0.4
V
Input High Voltage
VIH
2.0
V
Input Low Voltage
VIL
Leakage Current
0.8
ILEAK
V
±5
µA
powered or unpowered
TA < 85°C
pull-up voltage < 3.6V if
unpowered
200
pF
capacitance to ground
SG Pin
Capacitive Drive
Capability
CBASE_SG
20
SMBus Timing
Input Capacitance
CIN
Clock Frequency
fSMB
Spike Suppression
tSP
Bus Free Time Stop
to Start
tBUF
1.3
µs
Start Setup Time
tSU:STA
0.6
µs
Start Hold Time
tHD:STA
0.6
µs
Stop Setup Time
tSU:STO
0.6
µs
Data Hold Time
tHD:DAT
0
µs
When transmitting to the master
Data Hold Time
tHD:DAT
0.3
µs
When receiving from the master
Data Setup Time
tSU:DAT
0.6
µs
Clock Low Period
tLOW
1.3
µs
Clock High Period
tHIGH
0.6
µs
Clock / Data Fall
Time
tFALL
 2013-2015 Microchip Technology Inc.
5
10
pF
400
kHz
50
ns
300
ns
Min = 20+0.1CLOAD ns
DS00001571B-page 9
CAP1298
TABLE 2-1:
ELECTRICAL SPECIFICATIONS (CONTINUED)
VDD = 3V to 5.5V, TA = 0°C to 85°C, all Typical values at TA = 25°C unless otherwise noted.
Characteristic
Symbol
Clock / Data Rise
Time
Capacitive Load
DS00001571B-page 10
Min
Typ
Max
Unit
Conditions
tRISE
300
ns
Min = 20+0.1CLOAD ns
CLOAD
400
pF
per bus line
 2013-2015 Microchip Technology Inc.
CAP1298
3.0
COMMUNICATIONS
3.1
Communications
The CAP1298 communicates using the SMBus or I2C protocol.
3.2
System Management Bus
The CAP1298 communicates with a host controller, such as an MCHP SIO, through the SMBus. The SMBus is a twowire serial communication protocol between a computer host and its peripheral devices. A detailed timing diagram is
shown in Figure 3-1. Stretching of the SMCLK signal is supported; however, the CAP1298 will not stretch the clock signal.
FIGURE 3-1:
SMBUS TIMING DIAGRAM
T HIGH
T LO W
T HD :STA
T SU:STO
T FALL
SM CLK
T RISE
T HD :STA
T SU:DAT
T HD :DAT
T SU :STA
SM D ATA
T BUF
P
3.2.1
S
S - Start Condition
S
P - Stop C ondition
P
SMBUS START BIT
The SMBus Start bit is defined as a transition of the SMBus Data line from a logic ‘1’ state to a logic ‘0’ state while the
SMBus Clock line is in a logic ‘1’ state.
3.2.2
SMBUS ADDRESS AND RD / WR BIT
The SMBus Address Byte consists of the 7-bit client address followed by the RD / WR indicator bit. If this RD / WR bit
is a logic ‘0’, then the SMBus Host is writing data to the client device. If this RD / WR bit is a logic ‘1’, then the SMBus
Host is reading data from the client device.
3.2.3
The CAP1298responds to SMBus address 0101_000(r/w). SMBUS DATA BYTES
All SMBus Data bytes are sent most significant bit first and composed of 8-bits of information.
3.2.4
SMBUS ACK AND NACK BITS
The SMBus client will acknowledge all data bytes that it receives. This is done by the client device pulling the SMBus
Data line low after the 8th bit of each byte that is transmitted. This applies to both the Write Byte and Block Write protocols.
The Host will NACK (not acknowledge) the last data byte to be received from the client by holding the SMBus data line
high after the 8th data bit has been sent. For the Block Read protocol, the Host will ACK each data byte that it receives
except the last data byte.
3.2.5
SMBUS STOP BIT
The SMBus Stop bit is defined as a transition of the SMBus Data line from a logic ‘0’ state to a logic ‘1’ state while the
SMBus clock line is in a logic ‘1’ state. When the CAP1298 detects an SMBus Stop bit and it has been communicating
with the SMBus protocol, it will reset its client interface and prepare to receive further communications.
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DS00001571B-page 11
CAP1298
3.2.6
SMBUS TIMEOUT
The CAP1298 includes an SMBus timeout feature. Following a 30ms period of inactivity on the SMBus where the
SMCLK pin is held low, the device will timeout and reset the SMBus interface.
The timeout function defaults to disabled. It can be enabled by setting the TIMEOUT bit in the Configuration register
(see Section 5.6, "Configuration Registers").
3.2.7
SMBUS AND I2C COMPATIBILITY
The major differences between SMBus and I2C devices are highlighted here. For more information, refer to the SMBus
2.0 specification.
CAP1298supports I2C fast mode at 400kHz. This covers the SMBus max time of 100kHz.
Minimum frequency for SMBus communications is 10kHz.
The SMBus client protocol will reset if the clock is held low longer than 30ms (timeout condition). This can be
enabled in the CAP1298 by setting the TIMEOUT bit in the Configuration register. I2C does not have a timeout.
The SMBus client protocol will reset if both the clock and the data line are high for longer than 200us (idle condition). This can be enabled in the CAP1298by setting the TIMEOUT bit in the Configuration register. I2C does
not have an idle condition.
I2C devices do not support the Alert Response Address functionality (which is optional for SMBus).
I2C devices support block read and write differently. I2C protocol allows for unlimited number of bytes to be sent
in either direction. The SMBus protocol requires that an additional data byte indicating number of bytes to read /
write is transmitted. The CAP1298 supports I2C formatting only.
1.
2.
3.
4.
5.
6.
3.3
SMBus Protocols
The CAP1298 is SMBus 2.0 compatible and supports Write Byte, Read Byte, Send Byte, and Receive Byte as valid
protocols as shown below.
All of the below protocols use the convention in Table 3-1.
TABLE 3-1:
3.3.1
PROTOCOL FORMAT
Data Sent to
Device
Data Sent to the
HOst
Data sent
Data sent
SMBUS WRITE BYTE
The Write Byte is used to write one byte of data to a specific register as shown in Table 3-2.
TABLE 3-2:
WRITE BYTE PROTOCOL
Start
Slave
Address
WR
ACK
Register
Address
ACK
Register
Data
ACK
Stop
1 ->0
0101_000
0
0
XXh
0
XXh
0
0 -> 1
3.3.2
SMBUS READ BYTE
The Read Byte protocol is used to read one byte of data from the registers as shown in Table 3-3.
DS00001571B-page 12
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CAP1298
TABLE 3-3:
Start
READ BYTE PROTOCOL
Slave Address
1->0
0101_000
3.3.3
WR
ACK
0
0
Register
Address
ACK
XXh
0
Start
Client Address
1 ->0
0101_000
RD
ACK
1
0
Register
Data
XXh
NACK
1
Stop
0 -> 1
SMBUS SEND BYTE
The Send Byte protocol is used to set the internal address register pointer to the correct address location. No data is
transferred during the Send Byte protocol as shown in Table 3-4.
APPLICATION NOTE: The Send Byte protocol is not functional in Deep Sleep (i.e., DSLEEP bit is set).
TABLE 3-4:
SEND BYTE PROTOCOL
Start
Slave Address
WR
ACK
Register Address
ACK
Stop
1 -> 0
0101_000
0
0
XXh
0
0 -> 1
3.3.4
SMBUS RECEIVE BYTE
The Receive Byte protocol is used to read data from a register when the internal register address pointer is known to
be at the right location (e.g. set via Send Byte). This is used for consecutive reads of the same register as shown in
Table 3-5.
APPLICATION NOTE: The Receive Byte protocol is not functional in Deep Sleep (i.e., DSLEEP bit is set).
TABLE 3-5:
RECEIVE BYTE PROTOCOL
Start
Slave Address
RD
ACK
Register Data
NACK
Stop
1 -> 0
0101_000
1
0
XXh
1
0 -> 1
3.4
I2C Protocols
The CAP1298 supports I2C Block Read and Block Write.
The protocols listed below use the convention in Table 3-1.
3.4.1
BLOCK READ
The Block Read is used to read multiple data bytes from a group of contiguous registers as shown in Table 3-6.
APPLICATION NOTE: When using the Block Read protocol, the internal address pointer will be automatically
incremented after every data byte is received. It will wrap from FFh to 00h.
TABLE 3-6:
BLOCK READ PROTOCOL
Start
Slave
Address
WR
ACK
Register
Address
ACK
Start
Slave Address
RD
ACK
Register Data
1->0
0101_000
0
0
XXh
0
1 ->0
0101_000
1
0
XXh
ACK
REGISTER
DATA
ACK
REGISTER
DATA
ACK
REGISTER
DATA
ACK
...
REGISTER
DATA
NACK
STOP
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DS00001571B-page 13
CAP1298
TABLE 3-6:
0
BLOCK READ PROTOCOL
XXh
3.4.2
0
XXh
0
XXh
0
...
XXh
1
BLOCK WRITE
The Block Write is used to write multiple data bytes to a group of contiguous registers as shown in Table 3-7.
APPLICATION NOTE: When using the Block Write protocol, the internal address pointer will be automatically
incremented after every data byte is received. It will wrap from FFh to 00h.
TABLE 3-7:
BLOCK WRITE PROTOCOL
Start
Slave
Address
WR
ACK
Register
Address
ACK
Register
Data
ACK
1 ->0
0101_000
0
0
XXh
0
XXh
0
Register
Data
ACK
Register
Data
ACK
...
Register
Data
ACK
Stop
XXh
0
XXh
0
...
XXh
0
0 -> 1
DS00001571B-page 14
 2013-2015 Microchip Technology Inc.
0 -> 1
CAP1298
4.0
GENERAL DESCRIPTION
The CAP1298 is a multiple channel capacitive touch sensor. It contains eight (8) individual capacitive touch sensor
inputs with programmable sensitivity for use in touch sensor applications. Each sensor input is calibrated to compensate
for system parasitic capacitance and automatically recalibrated to compensate for gradual environmental changes.
In addition, the CAP1298 can be configured to detect proximity on one or more channels with an optional signal guard
to reduce noise sensitivity.
The CAP1298includes Multiple Pattern Touch recognition that allows the user to select a specific set of buttons to be
touched simultaneously. If this pattern is detected, a status bit is set and an interrupt is generated.
The CAP1298 has Active and Standby states, each with its own sensor input configuration controls. The Combo state
allows a combination of sensor input controls to be used which enables one or more sensor inputs to operate as buttons
while another sensor input is operating as a proximity detector. Power consumption in the Standby and Combo states
is dependent on the number of sensor inputs enabled as well as averaging, sampling time, and cycle time. Deep Sleep
is the lowest power state available, drawing 5µA (typical) of current. In this state, no sensor inputs are active, and communications will wake the device.
The device communicates with a host controller using SMBus / I2C. The host controller may poll the device for updated
information at any time or it may configure the device to flag an interrupt whenever a touch is detected on any sensor
pad.
A typical system diagram is shown in Figure 4-1.
FIGURE 4-1:
SYSTEM DIAGRAM FOR CAP1298
3.0V to 5.5V
Embedded
Controller
10kOhm
resistors
3.0V to 5.5V
Touch
Button
CS1
Touch
Button
CS2
Touch
Button
Proximity
Sensor
ALERT#
SMDATA
GND
SMCLK
0.1uF
VDD
CS8
Touch
Button
CS3
CS7
Touch
Button
CS4
CS6
Touch
Button
CAP1298
1.0uF
SG*
* CS5 / SG is a multi-function pin. If not
using the signal guard shown here, CS5
can be another touch button.
 2013-2015 Microchip Technology Inc.
DS00001571B-page 15
CAP1298
4.1
Power States
The CAP1298 has 4 power states depending on the status of the STBY, COMBO, and DSLEEP bits. When the device
transitions between power states, previously detected touches (for channels that are being de-activated) are cleared
and the sensor input status bits are reset.
1.
2.
3.
4.
Active - The normal mode of operation. The device is monitoring capacitive sensor inputs enabled in the Active
state.
Standby - When the STBY bit is set, the device is monitoring the capacitive sensor inputs enabled in the Standby
state. Interrupts can still be generated based on the enabled channels. The device will still respond to communications normally and can be returned to the Active state of operation by clearing the STBY bit. Power consumption in this state is dependent on the number of sensor inputs enabled as well as averaging, sampling time, and
cycle time.
Combo - When the COMBO bit is set, the device is monitoring capacitive sensor inputs enabled in the Active
state as well as inputs enabled in the Standby state (hence the name “Combo”). Interrupts can still be generated
based on the enabled channels. The device will still respond to communications normally and can be returned
to the Active state of operation by clearing the COMBO bit. Power consumption in this state is dependent on the
number of sensor inputs enabled as well as averaging, sampling time, and cycle time.
Deep Sleep - When the DSLEEP bit is set, the device is in its lowest power state. It is not monitoring any capacitive sensor inputs. While in Deep Sleep, the CAP1298 can be awakened by SMBus communications targeting
the device. This will not cause the DSLEEP to be cleared so the device will return to Deep Sleep once all communications have stopped. The device can be returned to the Active state of operation by clearing the DSLEEP
bit.
4.2
Reset
The Power-On Reset (POR) circuit holds the device in reset until VDD has reached an acceptable level, Power-on Reset
Release Voltage (VPORR), for minimum operation. The power-up timer (PWRT) is used to extend the start-up period until
all device operation conditions have been met. The power-up timer starts after VDD reaches VPORR. POR and PORR
with slow rising VDD is shown in Figure 4-2.
The Brown-Out Reset (BOR) circuit holds the device in reset when VDD falls to a minimum level, VBOR for longer than
the BOR reset delay (tBORDC). After a BOR, when VDD rises above VPORR, the power-up timer is started again and must
finish before reset is released, as shown in Figure 4-2.
FIGURE 4-2:
POR AND PORR WITH SLOW RISING VDD AND BOR WITH FALLING VDD
VPORR
VBOR
VPOR
VDD
GND
SYSRST
TPWRT
TBORDC TPWRT
Undefined
4.3
Capacitive Touch Sensing
The CAP1298 contains eight (8) independent capacitive touch sensor inputs. Each sensor input has dynamic range to
detect a change of capacitance due to a touch. Additionally, each sensor input can be configured to be automatically
and routinely recalibrated.
4.3.1
CAPACITIVE TOUCH SENSING SETTINGS
Controls for managing capacitive touch sensor inputs are determined by the power state.
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4.3.1.1
Active State Sensing Settings
The Active state is used for normal operation. Sensor inputs being monitored are determined by the Sensor Input Enable
Register(see Section 5.7, "Sensor Input Enable Register"). Sensitivity is controlled by the Sensitivity Control Register
(see Section 5.5, "Sensitivity Control Register"). Averaging, sample time, and cycle time are controlled by the Averaging
and Sampling Configuration Register (see Section 5.10, "Averaging and Sampling Configuration Register"). Each channel can have a separate touch detection threshold, as defined in the Sensor Input Threshold registers (see Section 5.19,
"Sensor Input Threshold Registers").
4.3.1.2
Standby State Sensing Settings
The Standby state is used for standby operation. In general, fewer sensor inputs are enabled, and they are programmed
to have more sensitivity. Sensor inputs being monitored are determined by the Standby Channel Register (see Section
5.21, "Standby Channel Register"). Sensitivity is controlled by the Standby Sensitivity Register (see Section 5.23,
"Standby Sensitivity Register"). Averaging, sample time, and cycle time are controlled by the Averaging and Sampling
Configuration Register (see Section 5.22, "Standby Configuration Register"). There is one touch detection threshold,
which applies to all sensors enabled in Standby, as defined in the Standby Threshold Register (see Section 5.24,
"Standby Threshold Register").
4.3.1.3
Combo State Sensing Settings
The Combo state is used when a combination of proximity detection and normal button operation is required. When the
COMBO bit is set, the sensing cycle includes sensor inputs enabled in the Active state as well as sensor inputs enabled
in the Standby state. Sensor inputs enabled in the Active state will use the Active settings described in Section 4.3.1.1,
"Active State Sensing Settings". Sensor inputs enabled in the Standby state will use the Standby settings described in
Section 4.3.1.2, "Standby State Sensing Settings". If a sensor input is enabled in both the Active state and in the Standby
state, the Active state settings will be used in Combo state. The programmed cycle time is determined by STBY_CY_TIME[1:0].
The Combo state also has two gain settings. When the COMBO bit is set, the GAIN[1:0] control only applies to the sensors enabled in the Active state, and the C_GAIN[1:0] control applies to the sensors enabled in the Standby state.
4.3.2
SENSING CYCLE
Except when in Deep Sleep, the device automatically initiates a sensing cycle and repeats the cycle every time it finishes. The cycle polls through each enabled sensor input starting with CS1 and extending through CS8. As each capacitive touch sensor input is polled, its measurement is compared against a baseline “not touched” measurement. If the
delta measurement is large enough to exceed the applicable threshold, a touch is detected and an interrupt can be generated (see Section 4.9.2, "Capacitive Sensor Input Interrupt Behavior").
The sensing cycle time is programmable (see Section 5.10, "Averaging and Sampling Configuration Register" and Section 5.22, "Standby Configuration Register"). If all enabled inputs can be sampled in less than the cycle time, the device
is placed into a lower power state for the remainder of the sensing cycle. If the number of active sensor inputs cannot
be sampled within the specified cycle time, the cycle time is extended and the device is not placed in a lower power
state.
4.4
Sensor Input Calibration
Calibration sets the Base Count Registers(Section 5.25, "Sensor Input Base Count Registers") which contain the “not
touched” values used for touch detection comparisons. Calibration automatically occurs after a power-on reset (POR),
when sample time is changed, when the gain is changed, when the calibration sensitivity is changed, and whenever a
sensor input is newly enabled (for example, when transitioning from a power state in which it was disabled to a power
state in which it is enabled). During calibration, the analog sensing circuits are tuned to the capacitance of the untouched
pad. Then, samples are taken from each sensor input so that a base count can be established. After calibration, the
untouched delta counts are zero.
APPLICATION NOTE: During the calibration routine, the sensor inputs will not detect a press for up to 200ms and
the Sensor Base Count Register values will be invalid. In addition, any press on the
corresponding sensor pads will invalidate the calibration.
The host controller can force a calibration for selected sensor inputs at any time using the Calibration Activate and Status
RegisterSection 5.10.1, "Calibration Activate and Status Register". When a bit is set, the corresponding capacitive touch
sensor input will be calibrated (both analog and digital). The bit is automatically cleared once the calibration routine has
successfully finished.
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If analog calibration fails for a sensor input, the corresponding bit is not cleared in the Calibration Activate and Status
Register, and the ACAL_FAIL bit is set in the General Status Register(Section 5.2, "Status Registers"). An interrupt can
be generated. Analog calibration will fail if a noise bit is set or if the calibration value is at the maximum or minimum
value. If digital calibration fails to generate base counts for a sensor input in the operating range, which is +12.5% from
the ideal base count (see TABLE 4-1:), indicating the base capacitance is out of range, the corresponding BC_OUTx bit
is set in the Base Count Out of Limit Register(Section 5.17, "Base Count Out of Limit Register"), and the BC_OUT bit
is set in the General Status Register (Section 5.2, "Status Registers"). An interrupt can be generated. By default, when
a base count is out of limit, analog calibration is repeated for the sensor input; alternatively, the sensor input can be
sampled using the out of limit base count(Section 5.6, "Configuration Registers"). Calibration sensitivity can be adjusted
for each sensor input based on capacitive touch pad capacitance.
TABLE 4-1:
IDEAL BASE COUNTS
Ideal Base Count
Sample Time
3,200
320us
6,400
640us
12,800
1.28ms
25,600
2.56ms
During normal operation there are various options for recalibrating the capacitive touch sensor inputs. Recalibration is
a digital adjustment of the base counts so that the untouched delta count is zero. After a recalibration, if a sensor input’s
base count has shifted +12.5% from the ideal base count, a full calibration will be performed on the sensor input.
4.4.1
AUTOMATIC RECALIBRATION
Each sensor input is regularly recalibrated at a programmable rate(see CAL_CFG[2:0] in Section 5.18, "Recalibration
Configuration Register"). By default, the recalibration routine stores the average 64 previous measurements and periodically updates the base “not touched” setting for the capacitive touch sensor input.
APPLICATION NOTE: Automatic recalibration only works when the delta count is below the active sensor input
threshold. It is disabled when a touch is detected.
4.4.2
NEGATIVE DELTA COUNT RECALIBRATION
It is possible that the device loses sensitivity to a touch. This may happen as a result of a noisy environment, recalibration when the pad is touched but delta counts do not exceed the threshold, or other environmental changes. When this
occurs, the base untouched sensor input may generate negative delta count values. The NEG_DELTA_CNT[1:0]
bits(see Section 5.18, "Recalibration Configuration Register") can be set to force a recalibration after a specified number
of consecutive negative delta readings. After a delayed recalibration (see Section 4.4.3, "Delayed Recalibration") the
negative delta count recalibration can correct after the touch is released.
APPLICATION NOTE: During this recalibration, the device will not respond to touches.
4.4.3
DELAYED RECALIBRATION
It is possible that a “stuck button” occurs when something is placed on a button which causes a touch to be detected
for a long period. By setting the MAX_DUR_EN bit(see Section 5.6, "Configuration Registers"), a recalibration can be
forced when a touch is held on a button for longer than the duration specified in the MAX_DUR[3:0] bits (see Section
5.8, "Sensor Input Configuration Register").
Note 4-1
Delayed recalibration only works when the delta count is above the active sensor input threshold. If
enabled, it is invoked when a sensor pad touch is held longer than the MAX_DUR bit settings.
Note 4-2
For the power button, which requires that the button be held longer than a regular button, the time
specified by the MAX_DUR[3:0] bits is added to the time required to trigger the qualifying event. This
will prevent the power button from being recalibrated during the time it is supposed to be held.
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4.5
Proximity Detection
Each sensor input can be configured to detect changes in capacitance due to proximity of a touch. This circuitry detects
the change of capacitance that is generated as an object approaches, but does not physically touch, the enabled sensor
pad(s). Generally, sensor inputs used to detect proximity have physically larger pads than standard buttons. In addition,
gain should be increased to increase sensitivity. To improve the signal, the signal guard feature may be used.
4.5.1
SIGNAL GUARD
The signal guard isolates the signal from virtual grounds, as shown in Figure 4-3. It can be used to isolate the proximity
antenna from nearby conductive surfaces that would otherwise attenuate the e-field.
FIGURE 4-3:
SIGNAL GUARD
CAP129X Device
SIGNAL_GUARD
4.6
CS pin
Touch Pad
CS pin
Touch Pad
Power Button
The CAP1298 has a “power button” feature. In general, buttons are set for quick response to a touch, especially when
buttons are used for number keypads. However, there are cases where a quick response is not desired, such as when
accidentally brushing the power button causes a device to turn off or on unexpectedly.
The power button feature allows a sensor input to be designated as the “power button” (see Section 5.26, "Power Button
Register"). The power button is configured so that a touch must be held on the button for a designated period of time
before an interrupt is generated; different times can be selected for the Standby and the Active states (see Section 5.27,
"Power Button Configuration Register"). The feature can also be enabled / disabled for both states separately.
APPLICATION NOTE: For the power button feature to work in the Standby and/or Active states, the sensor input
must be enabled in the applicable state. If the power button feature is enabled for both
Standby and Active and the COMBO bit is set, the Standby power button settings will be
used.
After the designated power button has been held for the designated time, an interrupt is generated and the PWR bit is
set in the General Status Register (see Section 5.2, "Status Registers").
4.7
Multiple Touch Pattern Detection
The multiple touch pattern (MTP) detection circuitry can be used to detect lid closure or other similar events. An event
can be flagged based on either a minimum number of sensor inputs or on specific sensor inputs simultaneously exceeding an MTP threshold or having their Noise Flag Status Register bits set. An interrupt can also be generated. During an
MTP event, all touches are blocked (see Section 5.15, "Multiple Touch Pattern Configuration Register").
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4.8
Noise Controls
4.8.1
LOW FREQUENCY NOISE DETECTION
Each sensor input has a low frequency noise detector that will sense if low frequency noise is injected onto the input
with sufficient power to corrupt the readings. By default, if this occurs, the device will reject the corrupted samplesee
DIS_ANA_NOISE bit in Section 5.6.1, "Configuration - 20h") and the corresponding bit is set to a logic ‘1’ in the Noise
Flag Status register (see SHOW_RF_NOISE bit in Section 5.6.2, "Configuration 2 - 44h").
4.8.2
RF NOISE DETECTION
Each sensor input contains an integrated RF noise detector. This block will detect injected RF noise on the CS pin. The
detector threshold is dependent upon the noise frequency. By default, if RF noise is detected on a CS line, that sample
is removed and not compared against the threshold (see DIS_RF_NOISE bit in Section 5.6.2, "Configuration 2 - 44h").
4.8.3
NOISE STATUS AND CONFIGURATION
The Noise Flag Status (see Section 5.3, "Noise Flag Status Registers") bits can be used to indicate RF and/or other
noise. If the SHOW_RF_NOISE bit in the Configuration Register (see Section 5.6, "Configuration Registers") is set to
0, the Noise Flag Status bit for the capacitive sensor input is set if any analog noise is detected. If the
SHOW_RF_NOISE bit is set to 1, the Noise Flag Status bits will only be set if RF noise is detected.
The CAP1208 offers optional noise filtering controls for both analog and digital noise.
For analog noise, there are options for whether the data should be considered invalid. By default, the DIS_ANA_NOISE
bit (see Section 5.6.1, "Configuration - 20h") will block a touch on a sensor input if low frequency analog noise is
detected; the sample is discarded. By default, the DIS_RF_NOISE bit (see Section 5.6.2, "Configuration 2 - 44h") will
block a touch on a sensor input if RF noise is detected; the sample is discarded.
For digital noise, sensor input noise thresholds can be set (see Section 5.20, "Sensor Input Noise Threshold Register").
If a capacitive touch sensor input exceeds the Sensor Noise Threshold but does not exceed the touch threshold (Sensor
Threshold (see Section 5.19, "Sensor Input Threshold Registers") in the Active state or Sensor Standby Threshold in
the Standby state (Section 5.24, "Standby Threshold Register")), it is determined to be caused by a noise spike. The
DIS_DIG_NOISE bit (see Section 5.6.1, "Configuration - 20h") can be set to discard samples that indicate a noise spike
so they are not used in the automatic recalibration routine (see Section 4.4.1, "Automatic Recalibration").
4.9
Interrupts
Interrupts are indicated by the setting of the INT bit in the Main Control Register(see Section 5.1, "Main Control Register") and by assertion of the ALERT# pin. The ALERT# pin is cleared when the INT bit is cleared by the user. When the
INT bit is cleared by the user, status bits may be cleared (see Section 5.2, "Status Registers").
4.9.1
ALERT# PIN
The ALERT# pin is an active low output that is driven when an interrupt event is detected.
4.9.2
CAPACITIVE SENSOR INPUT INTERRUPT BEHAVIOR
Each sensor input can be programmed to enable / disable interrupts(see Section 5.11, "Interrupt Enable Register").
When enabled for a sensor input and the sensor input is not the designated power button, interrupts are generated in
one of two ways:
1.
2.
An interrupt is generated when a touch is detected and, as a user selectable option, when a release is detected
(by default - see INT_REL_n in Section 5.6.2, "Configuration 2 - 44h"). See FIGURE 4-5:.
If the repeat rate is enabled then, so long as the touch is held, another interrupt will be generated based on the
programmed repeat rate (see FIGURE 4-4:).
When the repeat rate is enabled for a sensor input (see Section 5.12, "Repeat Rate Enable Register"), the device uses
an additional control called MPRESS that determines whether a touch is flagged as a simple “touch” or a “press and
hold” (see Section 5.9, "Sensor Input Configuration 2 Register"). The MPRESS[3:0] bits set a minimum press timer.
When the button is touched, the timer begins. If the sensor pad is released before the minimum press timer expires, it
is flagged as a touch and an interrupt (if enabled) is generated upon release. If the sensor input detects a touch for longer than this timer value, it is flagged as a “press and hold” event. So long as the touch is held, interrupts will be generated at the programmed repeat rate (see Section 5.8, "Sensor Input Configuration Register") and upon release (if
enabled).
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If a sensor input is the designated power button, an interrupt is not generated as soon as a touch is detected and repeat
rate is not applicable. See Section 4.9.3, "Interrupts for the Power Button".
APPLICATION NOTE: FIGURE 4-4: and FIGURE 4-5: show default operation which is to generate an interrupt upon
sensor pad release.
APPLICATION NOTE: The host may need to poll the device twice to determine that a release has been detected.
FIGURE 4-4:
Interrupt on
Touch
SENSOR INTERRUPT BEHAVIOR - REPEAT RATE ENABLED
Sensing Cycle
(35ms)
Min Press Setting
(280ms)
Touch Detected
Button Repeat Rate
(175ms)
Interrupt on
Release
(optional)
Button Repeat Rate
(175ms)
INT bit
ALERT# pin
Button Status
Write to INT bit
FIGURE 4-5:
Interrupt on
Touch
SENSOR INTERRUPT BEHAVIOR - NO REPEAT RATE ENABLED
Sensing Cycle
(35ms)
Touch Detected
Interrupt on
Release
(optional)
INT bit
ALERT# pin
Button Status
Write to INT bit
4.9.3
INTERRUPTS FOR THE POWER BUTTON
Interrupts are automatically enabled for the power button when the feature is enabled (see Section 4.6, "Power Button").
A touch must be held on the power button for the designated period of time before an interrupt is generated.
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4.9.4
INTERRUPTS FOR MULTIPLE TOUCH PATTERN DETECTION
An interrupt can be generated when the MTP pattern is matched (see Section 5.15, "Multiple Touch Pattern Configuration Register").
4.9.5
INTERRUPTS FOR SENSOR INPUT CALIBRATION FAILURES
An interrupt can be generated when the ACAL_FAIL bit is set, indicating the failure to complete analog calibration of
one or more sensor inputs(see Section 5.2, "Status Registers"). This interrupt can be enabled by setting the ACAL_FAIL_INT bit (see Section 5.6, "Configuration Registers").
An interrupt can be generated when the BC_OUT bit is set, indicating the base count is out of limit for one or more sensor inputs(see Section 5.2, "Status Registers"). This interrupt can be enabled by setting the BC_OUT_INT bit (see Section 5.6, "Configuration Registers").
4.9.6
INTERRUPTS FOR RESET
When the CAP1298 comes out of reset, an interrupt is generated, and the RESET bit is set.
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5.0
REGISTER DESCRIPTION
The registers shown in Table 5-1 are accessible through the communications protocol. An entry of ‘-’ indicates that the
bit is not used and will always read ‘0’.
TABLE 5-1:
REGISTER SET IN HEXADECIMAL ORDER
Register
Address
R/W
Register Name
Function
Default
Value
Page
00h
R/W
Main Control
Controls power states and indicates
an interrupt
00h
Page 26
02h
R/W
General Status
Stores general status bits
00h
Page 28
03h
R
Sensor Input Status
Returns the state of the sampled
capacitive touch sensor inputs
00h
Page 28
0Ah
R
Noise Flag Status
Stores the noise flags for sensor
inputs
00h
Page 29
10h
R
Sensor Input 1 Delta
Count
Stores the delta count for CS1
00h
Page 30
11h
R
Sensor Input 2 Delta
Count
Stores the delta count for CS2
00h
Page 30
12h
R
Sensor Input 3 Delta
Count
Stores the delta count for CS3
00h
Page 30
13h
R
Sensor Input 4 Delta
Count
Stores the delta count for CS4
00h
Page 30
14h
R
Sensor Input 5 Delta
Count
Stores the delta count for CS5
00h
Page 30
15h
R
Sensor Input 6 Delta
Count
Stores the delta count for CS6
00h
Page 30
16h
R
Sensor Input 7 Delta
Count
Stores the delta count for CS7
00h
Page 30
17h
R
Sensor Input 8 Delta
Count
Stores the delta count for CS8
00h
Page 30
1Fh
R/W
Sensitivity Control
Controls the sensitivity of the
threshold and delta counts and data
scaling of the base counts
2Fh
Page 30
20h
R/W
Configuration
Controls general functionality
20h
Page 32
21h
R/W
Sensor Input Enable
Controls which sensor inputs are
monitored in Active
FFh
Page 33
22h
R/W
Sensor Input
Configuration
Controls max duration and autorepeat delay
A4h
Page 34
23h
R/W
Sensor Input
Configuration 2
Controls the MPRESS (“press and
hold”) setting
07h
Page 35
24h
R/W
Averaging and
Sampling Config
Controls averaging and sampling
window for Active
39h
Page 36
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TABLE 5-1:
REGISTER SET IN HEXADECIMAL ORDER (CONTINUED)
Register
Address
R/W
Register Name
Function
Default
Value
Page
26h
R/W
Calibration Activate
and Status
Forces calibration for capacitive
touch sensor inputs and indicates
calibration failure
00h
Page 38
27h
R/W
Interrupt Enable
Determines which capacitive sensor
inputs can generate interrupts
FFh
Page 39
28h
R/W
Repeat Rate Enable
Enables repeat rate for specific
sensor inputs
FFh
Page 39
29h
R/W
Signal Guard Enable
Enables the signal guard for specific
sensor inputs
00h
Page 40
2Ah
R/W
Multiple Touch
Configuration
Determines the number of
simultaneous touches to flag a
multiple touch condition
80h
Page 40
2Bh
R/W
Multiple Touch Pattern
Configuration
Determines the multiple touch
pattern (MTP) configuration
00h
Page 41
2Dh
R/W
Multiple Touch Pattern
Determines the pattern or number of
sensor inputs used by the MTP
circuitry
FFh
Page 42
2Eh
R
Base Count Out of
Limit
Indicates whether sensor inputs
have a base count out of limit
00h
Page 43
2Fh
R/W
Recalibration
Configuration
Determines recalibration timing and
sampling window
8Ah
Page 43
30h
R/W
Sensor Input 1
Threshold
Stores the touch detection threshold
for Active for CS1
40h
Page 45
31h
R/W
Sensor Input 2
Threshold
Stores the touch detection threshold
for Active for CS2
40h
Page 45
32h
R/W
Sensor Input 3
Threshold
Stores the touch detection threshold
for Active for CS3
40h
Page 45
33h
R/W
Sensor Input 4
Threshold
Stores the touch detection threshold
for Active for CS4
40h
Page 45
34h
R/W
Sensor Input 5
Threshold
Stores the touch detection threshold
for Active for CS5
40h
Page 45
35h
R/W
Sensor Input 6
Threshold
Stores the touch detection threshold
for Active for CS6
40h
Page 45
36h
R/W
Sensor Input 7
Threshold
Stores the touch detection threshold
for Active for CS7
40h
Page 45
37h
R/W
Sensor Input 8
Threshold
Stores the touch detection threshold
for Active for CS8
40h
38h
R/W
Sensor Input Noise
Threshold
Stores controls for selecting the
noise threshold for all sensor inputs
01h
Page 45
00h
Page 46
Standby Configuration Registers
40h
R/W
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Standby Channel
Controls which sensor inputs are
enabled for Standby
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TABLE 5-1:
REGISTER SET IN HEXADECIMAL ORDER (CONTINUED)
Register
Address
R/W
Register Name
Function
Default
Value
Page
41h
R/W
Standby Configuration
Controls averaging and sensing
cycle time for Standby
39h
Page 46
42h
R/W
Standby Sensitivity
Controls sensitivity settings used for
Standby
02h
Page 48
43h
R/W
Standby Threshold
Stores the touch detection threshold
for Standby
40h
Page 49
44h
R/W
Configuration 2
Stores additional configuration
controls for the device
40h
Page 32
Base Count Registers
50h
R
Sensor Input 1 Base
Count
Stores the reference count value for
sensor input 1
C8h
Page 49
51h
R
Sensor Input 2 Base
Count
Stores the reference count value for
sensor input 2
C8h
Page 49
52h
R
Sensor Input 3 Base
Count
Stores the reference count value for
sensor input 3
C8h
Page 49
53h
R
Sensor Input 4 Base
Count
Stores the reference count value for
sensor input 4
C8h
Page 49
54h
R
Sensor Input 5 Base
Count
Stores the reference count value for
sensor input 5
C8h
Page 49
55h
R
Sensor Input 6 Base
Count
Stores the reference count value for
sensor input 6
C8h
Page 49
56h
R
Sensor Input 7 Base
Count
Stores the reference count value for
sensor input 7
C8h
Page 49
57h
R
Sensor Input 8 Base
Count
Stores the reference count value for
sensor input 8
C8h
Page 49
Power Button Registers
60h
R/W
Power Button
Specifies the power button
00h
Page 50
61h
R/W
Power Button
Configuration
Configures the power button feature
22h
Page 50
Calibration Sensitivity Configuration Registers
80h
R/W
Calibration Sensitivity
Configuration 1
Stores calibration sensitivity settings
for proximity
00h
Page 52
81h
R/W
Calibration Sensitivity
Configuration 2
Stores calibration sensitivity settings
for proximity
00h
Page 52
Calibration Registers
B1h
B2h
R
Sensor Input 1
Calibration
Stores the upper 8-bit calibration
value for CS1
00h
Page 51
R
Sensor Input 2
Calibration
Stores the upper 8-bit calibration
value for CS2
00h
Page 51
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TABLE 5-1:
REGISTER SET IN HEXADECIMAL ORDER (CONTINUED)
Register
Address
B3h
B4h
B5h
B6h
B7h
B8h
B9h
BAh
R/W
Register Name
Function
Default
Value
Page
R
Sensor Input 3
Calibration
Stores the upper 8-bit calibration
value for CS3
00h
Page 51
R
Sensor Input 4
Calibration
Stores the upper 8-bit calibration
value for CS4
00h
Page 51
R
Sensor Input 5
Calibration
Stores the upper 8-bit calibration
value for CS5
00h
Page 51
R
Sensor Input 6
Calibration
Stores the upper 8-bit calibration
value for CS6
00h
Page 51
R
Sensor Input 7
Calibration
Stores the upper 8-bit calibration
value for CS7
00h
Page 51
R
Sensor Input 8
Calibration
Stores the upper 8-bit calibration
value for CS8
00h
Page 51
R
Sensor Input
Calibration LSB 1
Stores the 2 LSBs of the calibration
value for CS1 - CS4
00h
Page 51
R
Sensor Input
Calibration LSB 2
Stores the 2 LSBs of the calibration
value for CS5 - CS8
00h
Page 51
ID Registers
FDh
R
Product ID
Stores a fixed value that identifies
the CAP1298
71h
Page 52
FEh
R
Manufacturer ID
Stores a fixed value that identifies
MCHP
5Dh
Page 53
FFh
R
Revision
Stores a fixed value that represents
the revision number
00h
Page 53
During power-on reset (POR), the default values are stored in the registers. A POR is initiated when power is first
applied to the part and the voltage on the VDD supply surpasses the POR level as specified in the electrical characteristics.
When a bit is “set”, this means it’s at a logic ‘1’. When a bit is “cleared”, this means it’s at a logic ‘0’.
5.1
TABLE 5-2:
Main Control Register
MAIN CONTROL REGISTER
Addr
R/W
Register
00h
R/W
Main Control
B7
B6
GAIN[1:0]
B5
B4
STBY
DSLEEP
B3
B2
C_GAIN[1:0]
B1
B0
Default
COMBO
INT
00h
The Main Control register controls the primary power state of the device (see Section 4.1, "Power States").
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If more than one power state bit is set, the actual power state will be as shown in Table 5-3, "Power State Bit Overrides".
TABLE 5-3:
POWER STATE BIT OVERRIDES
DSLEEP
COMBO
STBY
Power State
0
0
0
Active
0
0
1
Standby
0
1
X
Combo
1
X
X
DSleep
Bits 7 - 6 - GAIN[1:0] - Controls the analog gain used by the capacitive touch sensing circuitry. As the gain is increased,
the effective sensitivity is likewise increased as a smaller delta capacitance is required to generate the same delta count
values. The sensitivity settings may need to be adjusted along with the gain settings such that data overflow does not
occur.
APPLICATION NOTE: The GAIN[1:0] settings apply to both Standby and Active states, unless the COMBO bit is
set. When the COMBO bit is set, this control only applies to the sensors enabled in the
Active state, and the C_GAIN[1:0] control applies to the sensors enabled in the Standby
state.
APPLICATION NOTE: Whenever the gain settings change, the device will recalibrate all sensor inputs as if they
had no base count.
TABLE 5-4:
GAIN AND C_GAIN BIT DECODE
GAIN[1:0] or C_GAIN[1:0]
Capacitive Touch Sensor Input Gain
1
0
0
0
1
0
1
2
1
0
4
1
1
8
Bit 5 - STBY - Enables Standby.
• ‘0’ (default) - The device is not in the Standby state.
• ‘1’ - The device is in the Standby state. Capacitive touch sensor input scanning is limited to the sensor inputs set in
the Standby Channel register (see Section 5.21, "Standby Channel Register"). The status registers will not be
cleared until read. Sensor inputs that are no longer sampled will flag a release and then remain in a non-touched
state.
Bit 4 - DSLEEP - Enables Deep Sleep.
• ‘0’ (default) - The device is not in the Deep Sleep state.
• ‘1’ - The device is in the Deep Sleep state. All sensor input scanning is disabled. The status registers are automatically cleared and the INT bit is cleared..
Bits 3 - 2 - C_GAIN[1:0] - When the COMBO bit is set, this bit controls the analog gain used for capacitive touch sensor
inputs enabled in the Standby state. As the gain is increased, the effective sensitivity is likewise increased as a smaller
delta capacitance is required to generate the same delta count values. The Standby sensitivity settings may need to be
adjusted along with the gain settings such that data overflow does not occur.
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CAP1298
APPLICATION NOTE: The C_GAIN[1:0] setting is only used if the COMBO bit is set. When the COMBO bit is set,
this control only applies to the sensors enabled in the Standby state, and the GAIN[1:0]
control applies to the sensors enabled in the Active state.
Bit 1 - COMBO - Enables Combo state (see Section 4.3.1.3, "Combo State Sensing Settings").
• ‘0’ (default) - The device is not in the Combo state.
• ‘1’ - The device is in the Combo state. The device is monitoring sensor inputs enabled in the Active state (see Section 5.7, "Sensor Input Enable Register") as well as those enabled in the Standby state (see Section 5.21,
"Standby Channel Register"). The status registers will not be cleared until read. Sensor inputs that are no longer
sampled will flag a release and then remain in a non-touched state.
Bit 0 - INT - Indicates that there is an interrupt (see Section 4.9, "Interrupts"). When this bit is set, it asserts the ALERT#
pin. If a channel detects a touch but interrupts are not enabled for that channel (see Section 5.11, "Interrupt Enable Register"), no action is taken. This bit is cleared by writing a logic ‘0’ to it. When this bit is cleared, the ALERT# pin will be
deasserted, and all status registers will be cleared if the condition has been removed.
• ‘0’ - No interrupt pending.
• ‘1’ - An interrupt condition occurred, and the ALERT# pin has been asserted.
5.2
Status Registers
TABLE 5-5:
STATUS REGISTERS
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
02h
R
General Status
-
BC_
OUT
ACAL
_FAIL
PWR
RESET
MULT
MTP
TOUCH
00h
03h
R
Sensor Input
Status
CS8
CS7
CS6
CS5
CS4
CS3
CS2
CS1
00h
All status bits are cleared when the device enters Deep Sleep (DSLEEP = ‘1’ - see Section 5.1, "Main Control Register").
5.2.1
GENERAL STATUS - 02H
Bit 6 - BC_OUT - Indicates that the base count is out of limit for one or more enabled sensor inputs (see Section 4.4,
"Sensor Input Calibration"). This bit will not be cleared until all enabled sensor inputs have base counts within the limit.
• ‘0’ - All enabled sensor inputs have base counts in the operating range.
• ‘1’ - One or more enabled sensor inputs has the base count out of limit. A status bit is set in the Base Count Out of
Limit Register (see Section 5.17, "Base Count Out of Limit Register").
Bit 5 - ACAL_FAIL - Indicates analog calibration failure for one or more enabled sensor inputs (see Section 4.4, "Sensor
Input Calibration"). This bit will not be cleared until all enabled sensor inputs have successfully completed analog calibration.
• ‘0’ - All enabled sensor inputs were successfully calibrated.
• ‘1’ - One or more enabled sensor inputs failed analog calibration. A status bit is set in the Calibration Active Register (see Section 5.10.1, "Calibration Activate and Status Register").
Bit 4 - PWR - Indicates that the designated power button has been held for the designated time (see Section 4.6, "Power
Button"). This bit will cause the INT bit to be set. This bit is cleared when the INT bit is cleared if there is no longer a
touch on the power button.
• ‘0’ - The power button has not been held for the required time or is not enabled.
• ‘1’ - The power button has been held for the required time.
Bit 3 - RESET - Indicates that the device has come out of reset. This bit is set when the device exits a POR state. This
bit will cause the INT bit to be set and is cleared when the INT bit is cleared.
Bit 2 - MULT - Indicates that the device is blocking detected touches due to the Multiple Touch detection circuitry (see
Section 5.14, "Multiple Touch Configuration Register"). This bit will not cause the INT bit to be set and hence will not
cause an interrupt.
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Bit 1 - MTP - Indicates that the device has detected a number of sensor inputs that exceed the MTP threshold either via
the pattern recognition or via the number of sensor inputs (see Section 5.15, "Multiple Touch Pattern Configuration Register"). This bit will cause the INT bit to be set if the MTP_ALERT bit is also set. This bit is cleared when the INT bit is
cleared if the condition that caused it to be set has been removed.
Bit 0 - TOUCH - Indicates that a touch was detected. This bit is set if any bit in the Sensor Input Status register is set.
5.2.2
SENSOR INPUT STATUS - 03H
The Sensor Input Status Register stores status bits that indicate a touch has been detected. A value of ‘0’ in any bit
indicates that no touch has been detected. A value of ‘1’ in any bit indicates that a touch has been detected.
All bits are cleared when the INT bit is cleared and if a touch on the respective capacitive touch sensor input is no longer
present. If a touch is still detected, the bits will not be cleared (but this will not cause the interrupt to be asserted).
Bit 7 - CS8 - Indicates that a touch was detected on Sensor Input 8.
Bit 6 - CS7 - Indicates that a touch was detected on Sensor Input 7.
Bit 5 - CS6 - Indicates that a touch was detected on Sensor Input 6.
Bit 4 - CS5 - Indicates that a touch was detected on Sensor Input 5.
Bit 3 - CS4 - Indicates that a touch was detected on Sensor Input 4.
Bit 2 - CS3 - Indicates that a touch was detected on Sensor Input 3.
Bit 1 - CS2 - Indicates that a touch was detected on Sensor Input 2.
Bit 0 - CS1 - Indicates that a touch was detected on Sensor Input 1.
5.3
TABLE 5-6:
Noise Flag Status Registers
NOISE FLAG STATUS REGISTERS
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
0Ah
R
Noise Flag
Status
CS8_
NOISE
CS7_
NOISE
CS6_
NOISE
CS5_
NOISE
CS4_
NOISE
CS3_
NOISE
CS2_
NOISE
CS1_
NOISE
00h
The Noise Flag Status registers store status bits that can be used to indicate that the analog block detected noise above
the operating region of the analog detector or the RF noise detector (see Section 4.8.3, "Noise Status and Configuration"). These bits indicate that the most recently received data from the sensor input is invalid and should not be used
for touch detection. So long as the bit is set for a particular channel, the delta count value is reset to 00h and thus no
touch is detected.
These bits are not sticky and will be cleared automatically if the analog block does not report a noise error.
APPLICATION NOTE: If the MTP detection circuitry is enabled, these bits count as sensor inputs above the MTP
threshold (see Section 4.7, "Multiple Touch Pattern Detection") even if the corresponding
delta count is not. If the corresponding delta count also exceeds the MTP threshold, it is not
counted twice.
APPLICATION NOTE: Regardless of the state of the Noise Status bits, if low frequency noise is detected on a
sensor input, that sample will be discarded unless the DIS_ANA_NOISE bit is set. As well,
if RF noise is detected on a sensor input, that sample will be discarded unless the
DIS_RF_NOISE bit is set.
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5.4
Sensor Input Delta Count Registers
TABLE 5-7:
SENSOR INPUT DELTA COUNT REGISTERS
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
10h
R
Sensor Input 1
Delta Count
Sign
64
32
16
8
4
2
1
00h
11h
R
Sensor Input 2
Delta Count
Sign
64
32
16
8
4
2
1
00h
12h
R
Sensor Input 3
Delta Count
Sign
64
32
16
8
4
2
1
00h
13h
R
Sensor Input 4
Delta Count
Sign
64
32
16
8
4
2
1
00h
14h
R
Sensor Input 5
Delta Count
Sign
64
32
16
8
4
2
1
00h
15h
R
Sensor Input 6
Delta Count
Sign
64
32
16
8
4
2
1
00h
16h
R
Sensor Input 7
Delta Count
Sign
64
32
16
8
4
2
1
00h
17h
R
Sensor Input 8
Delta Count
Sign
64
32
16
8
4
2
1
00h
The Sensor Input Delta Count registers store the delta count that is compared against the threshold used to determine
if a touch has been detected. The count value represents a change in input due to the capacitance associated with a
touch on one of the sensor inputs and is referenced to a calibrated base “not touched” count value. The delta is an
instantaneous change and is updated once per sensor input per sensing cycle (see Section 4.3.2, "Sensing Cycle").
The value presented is a standard 2’s complement number. In addition, the value is capped at a value of 7Fh. A reading
of 7Fh indicates that the sensitivity settings are too high and should be adjusted accordingly (see Section 5.5).
The value is also capped at a negative value of 80h for negative delta counts which may result upon a release.
5.5
TABLE 5-8:
Sensitivity Control Register
SENSITIVITY CONTROL REGISTER
Addr
R/W
Register
B7
1Fh
R/W
Sensitivity Control
-
B6
B5
B4
DELTA_SENSE[2:0]
B3
B2
B1
B0
Default
BASE_SHIFT[3:0]
The Sensitivity Control register controls the sensitivity of a touch detection.
Bits 6-4 DELTA_SENSE[2:0] - Controls the sensitivity of a touch detection for sensor inputs enabled in the Active state.
The sensitivity settings act to scale the relative delta count value higher or lower based on the system parameters. A
setting of 000b is the most sensitive while a setting of 111b is the least sensitive. At the more sensitive settings, touches
are detected for a smaller delta capacitance corresponding to a “lighter” touch. These settings are more sensitive to
noise, however, and a noisy environment may flag more false touches with higher sensitivity levels.
APPLICATION NOTE: A value of 128x is the most sensitive setting available. At the most sensitive settings, the
MSB of the Delta Count register represents 64 out of ~25,000 which corresponds to a touch
of approximately 0.25% of the base capacitance (or a C of 25fF from a 10pF base
capacitance). Conversely, a value of 1x is the least sensitive setting available. At these
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CAP1298
settings, the MSB of the Delta Count register corresponds to a delta count of 8192 counts
out of ~25,000 which corresponds to a touch of approximately 33% of the base capacitance
(or a C of 3.33pF from a 10pF base capacitance).
TABLE 5-9:
DELTA_SENSE BIT DECODE
DELTA_SENSE[2:0]
Sensitivity Multiplier
2
1
0
0
0
0
128x (most sensitive)
0
0
1
64x
0
1
0
32x (default)
0
1
1
16x
1
0
0
8x
1
0
1
4x
1
1
0
2x
1
1
1
1x - (least sensitive)
Bits 3 - 0 - BASE_SHIFT[3:0] - Controls the scaling and data presentation of the Base Count registers. The higher the
value of these bits, the larger the range and the lower the resolution of the data presented. The scale factor represents
the multiplier to the bit-weighting presented in these register descriptions.
APPLICATION NOTE: The BASE_SHIFT[3:0] bits normally do not need to be updated. These settings will not affect
touch detection or sensitivity. These bits are sometimes helpful in analyzing the Cap Sensing
board performance and stability.
TABLE 5-10:
BASE_SHIFT BIT DECODE
BASE_SHIFT[3:0]
Data Scaling Factor
3
2
1
0
0
0
0
0
1x
0
0
0
1
2x
0
0
1
0
4x
0
0
1
1
8x
0
1
0
0
16x
0
1
0
1
32x
0
1
1
0
64x
0
1
1
1
128x
1
0
0
0
256x
All others
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256x
(default = 1111b)
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5.6
Configuration Registers
TABLE 5-11:
CONFIGURATION REGISTERS
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
20h
R/W
Configuration
TIME
OUT
-
DIS_
DIG_
NOISE
DIS_
ANA_
NOISE
MAX_
DUR_EN
-
-
-
20h
44h
R/W
Configuration
2
-
BC_
OUT_
RECAL
BLK_
PWR_
CTRL
BC_
OUT_
INT
SHOW_
RF_
NOISE
DIS_
RF_
NOISE
ACAL
_FAIL
_INT
INT_
REL_
n
40h
The Configuration registers control general global functionality that affects the entire device.
5.6.1
CONFIGURATION - 20H
Bit 7 - TIMEOUT - Enables the timeout and idle functionality of the SMBus protocol.
• ‘0’ (default) - The SMBus timeout and idle functionality are disabled. The SMBus interface will not time out if the
clock line is held low. Likewise, it will not reset if both the data and clock lines are held high for longer than 200us.
• ‘1’ - The SMBus timeout and idle functionality are enabled. The SMBus interface will reset if the clock line is held
low for longer than 30ms. Likewise, it will reset if both the data and clock lines are held high for longer than 200us.
Bit 5 - DIS_DIG_NOISE - Determines whether the digital noise threshold (see Section 5.20, "Sensor Input Noise Threshold Register") is used by the device. Setting this bit disables the feature.
• ‘0’ - The digital noise threshold is used. If a delta count value exceeds the noise threshold but does not exceed the
touch threshold, the sample is discarded and not used for the automatic recalibration routine.
• ‘1’ (default) - The noise threshold is disabled. Any delta count that is less than the touch threshold is used for the
automatic recalibration routine.
Bit 4 - DIS_ANA_NOISE - Determines whether the analog noise filter is enabled. Setting this bit disables the feature.
• ‘0’ (default) - If low frequency noise is detected by the analog block, the delta count on the corresponding channel
is set to 0. Note that this does not require that Noise Status bits be set.
• ‘1’ - A touch is not blocked even if low frequency noise is detected.
Bit 3 - MAX_DUR_EN - Determines whether the maximum duration recalibration is enabled.
• ‘0’ (default) - The maximum duration recalibration functionality is disabled. A touch may be held indefinitely and no
recalibration will be performed on any sensor input.
• ‘1’ - The maximum duration recalibration functionality is enabled. If a touch is held for longer than the MAX_DUR
bit settings (see Section 5.8), the recalibration routine will be restarted (see Section 4.4.3, "Delayed Recalibration").
5.6.2
CONFIGURATION 2 - 44H
Bit 6 - BC_OUT_RECAL - Controls whether to retry analog calibration when the base count is out of limit for one or more
sensor inputs.
• ‘0’ - When the BC_OUTx bit is set for a sensor input, the out of limit base count will be used for the sensor input.
• ‘1’ (default) - When the BC_OUTx bit is set for a sensor input (see Section 5.17, "Base Count Out of Limit Register"), analog calibration will be repeated on the sensor input.
Bit 5 - BLK_PWR_CTRL - Determines whether the device will reduce power consumption while waiting between conversion time completion and the end of the sensing cycle.
• ‘0’ (default) - The device will reduce power consumption during the time between the end of the last conversion
and the end of the sensing cycle.
• ‘1’ - The device will not reduce power consumption during the time between the end of the last conversion and the
end of the sensing cycle.
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Bit 4 - BC_OUT_INT - Controls the interrupt behavior when the base count is out of limit for one or more sensor inputs.
• ‘0’ (default) - An interrupt is not generated when the BC_OUT bit is set (see Section 5.2, "Status Registers").
• ‘1’ - An interrupt is generated when the BC_OUT bit is set.
Bit 3 - SHOW_RF_NOISE - Determines whether the Noise Status bits will show RF Noise as the only input source.
• ‘0’ (default) - The Noise Status registers will show both RF noise and low frequency noise if either is detected on a
capacitive touch sensor input.
• ‘1’ - The Noise Status registers will only show RF noise if it is detected on a capacitive touch sensor input. Low frequency noise will still be detected and touches will be blocked normally; however, the status bits will not be
updated.
Bit 2 - DIS_RF_NOISE - Determines whether the RF noise filter is enabled. Setting this bit disables the feature.
• ‘0’ (default) - If RF noise is detected by the analog block, the delta count on the corresponding channel is set to 0.
Note that this does not require that Noise Status bits be set.
• ‘1’ - A touch is not blocked even if RF noise is detected.
Bit 1 - ACAL_FAIL_INT - Controls the interrupt behavior when analog calibration fails for one or more sensor inputs (see
Section 4.4, "Sensor Input Calibration").
• ‘0’ (default) - An interrupt is not generated when the ACAL_FAIL bit is set (see Section 5.2, "Status Registers").
• ‘1’ - An interrupt is generated when the ACAL_FAIL bit is set
Bit 0 - INT_REL_n - Controls the interrupt behavior when a release is detected on a button (see Section 4.9.2, "Capacitive Sensor Input Interrupt Behavior").
• ‘0’ (default) - An interrupt is generated when a press is detected and again when a release is detected and at the
repeat rate (if enabled - see Section 5.12).
• ‘1’ - An interrupt is generated when a press is detected and at the repeat rate but not when a release is detected.
5.7
TABLE 5-12:
Sensor Input Enable Register
SENSOR INPUT ENABLE REGISTER
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
21h
R/W
Sensor Input
Enable
CS8_EN
CS7_EN
CS6_EN
CS5_EN
CS4_EN
CS3_EN
CS2_EN
CS1_EN
FFh
The Sensor Input Enable register determines whether a capacitive touch sensor input is included in the sensing cycle
in the Active state.
For all bits in this register:
• ‘0’ - The specified input is not included in the sensing cycle in the Active state.
• ‘1’ (default) - The specified input is included in the sensing cycle in the Active state.
Bit 7 - CS8_EN - Determines whether the CS8 input is monitored in the Active state.
Bit 6 - CS7_EN - Determines whether the CS7 input is monitored in the Active state.
Bit 5 - CS6_EN - Determines whether the CS6 input is monitored in the Active state.
Bit 4 - CS5_EN - Determines whether the CS5 input is monitored in the Active state.
Bit 3 - CS4_EN - Determines whether the CS4 input is monitored in the Active state.
Bit 2 - CS3_EN - Determines whether the CS3 input is monitored in the Active state.
Bit 1 - CS2_EN - Determines whether the CS2 input is monitored in the Active state.
Bit 0 - CS1_EN - Determines whether the CS1 input is monitored in the Active state.
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CAP1298
5.8
Sensor Input Configuration Register
TABLE 5-13:
SENSOR INPUT CONFIGURATION REGISTER
Addr
R/W
Register
22h
R/W
Sensor Input
Configuration
B7
B6
B5
B4
MAX_DUR[3:0]
B3
B2
B1
B0
RPT_RATE[3:0]
Default
A4h
The Sensor Input Configuration Register controls timings associated with the capacitive sensor inputs.
Bits 7 - 4 - MAX_DUR[3:0] - (default 1010b) - Determines the maximum time that a sensor pad is allowed to be touched
until the capacitive touch sensor input is recalibrated (see Section 4.4.3, "Delayed Recalibration"), as shown in Table 514.
TABLE 5-14:
MAX_DUR BIT DECODE
MAX_DUR[3:0]
Time before Recalibration
3
2
1
0
0
0
0
0
560ms
0
0
0
1
840ms
0
0
1
0
1120ms
0
0
1
1
1400ms
0
1
0
0
1680ms
0
1
0
1
2240ms
0
1
1
0
2800ms
0
1
1
1
3360ms
1
0
0
0
3920ms
1
0
0
1
4480ms
1
0
1
0
5600ms (default)
1
0
1
1
6720ms
1
1
0
0
7840ms
1
1
0
1
8906ms
1
1
1
0
10080ms
1
1
1
1
11200ms
Bits 3 - 0 - RPT_RATE[3:0] - (default 0100b) Determines the time duration between interrupt assertions when auto
repeat is enabled (see Section 4.9.2, "Capacitive Sensor Input Interrupt Behavior"). The resolution is 35ms and the
range is from 35ms to 560ms as shown in Table 5-15.
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CAP1298
TABLE 5-15:
RPT_RATE BIT DECODE
RPT_RATE[3:0]
Interrupt Repeat Rate
5.9
3
2
1
0
0
0
0
0
35ms
0
0
0
1
70ms
0
0
1
0
105ms
0
0
1
1
140ms
0
1
0
0
175ms (default)
0
1
0
1
210ms
0
1
1
0
245ms
0
1
1
1
280ms
1
0
0
0
315ms
1
0
0
1
350ms
1
0
1
0
385ms
1
0
1
1
420ms
1
1
0
0
455ms
1
1
0
1
490ms
1
1
1
0
525ms
1
1
1
1
560ms
Sensor Input Configuration 2 Register
TABLE 5-16:
SENSOR INPUT CONFIGURATION 2 REGISTER
Addr
R/W
Register
B7
B6
B5
B4
23h
R/W
Sensor Input
Configuration 2
-
-
-
-
B3
B2
B1
M_PRESS[3:0]
B0
Default
07h
Bits 3 - 0 - M_PRESS[3:0] - (default 0111b) - Determines the minimum amount of time that sensor inputs configured to
use auto repeat must detect a sensor pad touch to detect a “press and hold” event (see Section 4.9.2, "Capacitive Sensor Input Interrupt Behavior"). If the sensor input detects a touch for longer than the M_PRESS[3:0] settings, a “press
and hold” event is detected. If a sensor input detects a touch for less than or equal to the M_PRESS[3:0] settings, a
touch event is detected.
The resolution is 35ms and the range is from 35ms to 560ms as shown in Table 5-17.
 2013-2015 Microchip Technology Inc.
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CAP1298
TABLE 5-17:
M_PRESS BIT DECODE
M_PRESS[3:0]
M_PRESS Settings
5.10
3
2
1
0
0
0
0
0
35ms
0
0
0
1
70ms
0
0
1
0
105ms
0
0
1
1
140ms
0
1
0
0
175ms
0
1
0
1
210ms
0
1
1
0
245ms
0
1
1
1
280ms (default)
1
0
0
0
315ms
1
0
0
1
350ms
1
0
1
0
385ms
1
0
1
1
420ms
1
1
0
0
455ms
1
1
0
1
490ms
1
1
1
0
525ms
1
1
1
1
560ms
Averaging and Sampling Configuration Register
TABLE 5-18:
AVERAGING AND SAMPLING CONFIGURATION REGISTER
Addr
R/W
Register
B7
24h
R/W
Averaging and
Sampling
Config
-
B6
B5
AVG[2:0]
B4
B3
B2
SAMP_TIME[1:0]
B1
B0
CYCLE_TIME
[1:0]
Default
39h
The Averaging and Sampling Configuration register controls the number of samples taken and the target sensing cycle
time for sensor inputs enabled in the Active state.
Bits 6 - 4 - AVG[2:0] - Determines the number of samples that are taken for all channels enabled in the Active state
during the sensing cycle as shown in Table 5-19. All samples are taken consecutively on the same channel before the
next channel is sampled and the result is averaged over the number of samples measured before updating the measured results.
For example, if CS1, CS2, and CS3 are sampled during the sensing cycle, and the AVG[2:0] bits are set to take 4 samples per channel, then the full sensing cycle will be: CS1, CS1, CS1, CS1, CS2, CS2, CS2, CS2, CS3, CS3, CS3, CS3.
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TABLE 5-19:
AVG BIT DECODE
AVG[2:0]
Number Of Samples Taken Per
Measurement
2
1
0
0
0
0
1
0
0
1
2
0
1
0
4
0
1
1
8 (default)
1
0
0
16
1
0
1
32
1
1
0
64
1
1
1
128
Bits 3 - 2 - SAMP_TIME[1:0] - Determines the time to take a single sample as shown in Table 5-20. Sample time affects
the magnitude of the base counts, as shown in Table 4-1, "Ideal Base Counts".
TABLE 5-20:
SAMP_TIME BIT DECODE
SAMP_TIME[1:0]
Sample Time
1
0
0
0
320us
0
1
640us
1
0
1.28ms (default)
1
1
2.56ms
Bits 1 - 0 - CYCLE_TIME[1:0] - Determines the desired sensing cycle time for channels enabled in the Active state, as
shown in Table 5-21. All enabled channels are sampled at the beginning of the sensing cycle. If additional time is
remaining, the device is placed into a lower power state for the remainder of the sensing cycle.
TABLE 5-21:
CYCLE_TIME BIT DECODE
CYCLE_TIME[1:0]
Programmed Sensing Cycle Time
1
0
0
0
35ms
0
1
70ms (default)
1
0
105ms
1
1
140ms
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APPLICATION NOTE: The programmed sensing cycle time (CYCLE_TIME[1:0]) is only maintained if the actual time
to take the samples is less than the programmed cycle time. The AVG[2:0] bits will take
priority, so the sensing cycle time will be extended as necessary to accommodate the
number of samples to be measured.
5.10.1
CALIBRATION ACTIVATE AND STATUS REGISTER
TABLE 5-22:
CALIBRATION ACTIVATE AND STATUS REGISTER
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
26h
R/W
Calibration
Activate
and Status
CS8_
CAL
CS7_
CAL
CS6_
CAL
CS5_
CAL
CS4_
CAL
CS3_
CAL
CS2_
CAL
CS1_
CAL
00h
The Calibration Activate and Status Register serves a dual function:
1.
It forces the selected sensor inputs to be calibrated, affecting both the analog and digital blocks (see Section 4.4,
"Sensor Input Calibration"). When one or more bits are set, the device performs the calibration routine on the
corresponding sensor inputs. When the analog calibration routine is finished, the CALX[9:0] bits are updated (see
Section 5.28, "Sensor Input Calibration Registers"). If the analog calibration routine completed successfully for a
sensor input, the corresponding bit is automatically cleared.
APPLICATION NOTE: In the case above, bits can be set by host or are automatically set by the device whenever
a sensor input is newly enabled (such as coming out of Deep Sleep, after power-on reset,
when a bit is set in the Sensor Enable Channel Enable register (21h) and the device is in
the Active state, or when a bit is set in the Standby Channel Enable Register (40h) and the
device is in the Standby state).
2. It serves as an indicator of an analog calibration failure. If any of the bits could not be cleared, the ACAL_FAIL
bit is set (see Section 5.2, "Status Registers"). A bit will fail to clear if a noise bit is set or if the calibration value
is at the maximum or minimum value.
APPLICATION NOTE: In the case above, do not check the Calibration Activate and Status bits for failures unless
the ACAL_FAIL bit is set. In addition, if a sensor input is newly enabled, do not check the
Calibration Activate and Status bits until time has elapsed to complete calibration on the
sensor input. Otherwise, the ACAL_FAIL bit may be set for one sensor input, but the newly
enabled sensor input may still be set to ‘1’ in the Calibration Activate and Status, not because
it failed, but because it has not been calibrated yet.
For all bits in this register:
• ‘0’ - No action needed.
• ‘1’ - Writing a ‘1’, forces a calibration on the corresponding sensor input. If the ACAL_FAIL flag is set and this bit is
set (see application note above), the sensor input could not complete analog calibration.
Bit 7 - CS8_CAL - Bit for CS8 input.
Bit 6 - CS7_CAL - Bit for CS7 input.
Bit 5 - CS6_CAL - Bit for CS6 input.
Bit 4 - CS5_CAL - Bit for CS5 input.
Bit 3 - CS4_CAL - Bit for CS4 input.
Bit 2 - CS3_CAL - Bit for CS3 input.
Bit 1 - CS2_CAL - Bit for CS2 input.
Bit 0 - CS1_CAL - Bit for CS1 input.
APPLICATION NOTE: Writing a ‘0’ to clear a ‘1’ may cause a planned calibration to be skipped, if the calibration
routine had not reached the sensor input yet.
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5.11
Interrupt Enable Register
TABLE 5-23:
INTERRUPT ENABLE REGISTER
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
27h
R/W
Interrupt
Enable
CS8_
INT_EN
CS7_
INT_EN
CS6_
INT_EN
CS5_
INT_EN
CS4_
INT_EN
CS3_
INT_EN
CS2_
INT_EN
CS1_
INT_EN
FFh
The Interrupt Enable register determines whether a sensor pad touch or release (if enabled) causes an interrupt (see
Section 4.9, "Interrupts").
For all bits in this register:
• ‘0’ - The ALERT# pin will not be asserted if a touch is detected on the specified sensor input.
• ‘1’ (default) - The ALERT# pin will be asserted if a touch is detected on the specified sensor input.
Bit 7 - CS8_INT_EN - Enables the ALERT# pin to be asserted if a touch is detected on CS8 (associated with the CS8
status bit).
Bit 6 - CS7_INT_EN - Enables the ALERT# pin to be asserted if a touch is detected on CS7 (associated with the CS7
status bit).
Bit 5 - CS6_INT_EN - Enables the ALERT# pin to be asserted if a touch is detected on CS6 (associated with the CS6
status bit).
Bit 4 - CS5_INT_EN - Enables the ALERT# pin to be asserted if a touch is detected on CS5 (associated with the CS5
status bit).
Bit 3 - CS4_INT_EN - Enables the ALERT# pin to be asserted if a touch is detected on CS4 (associated with the CS4
status bit).
Bit 2 - CS3_INT_EN - Enables the ALERT# pin to be asserted if a touch is detected on CS3 (associated with the CS3
status bit).
Bit 1 - CS2_INT_EN - Enables the ALERT# pin to be asserted if a touch is detected on CS2 (associated with the CS2
status bit).
Bit 0 - CS1_INT_EN - Enables the ALERT# pin to be asserted if a touch is detected on CS1 (associated with the CS1
status bit).
5.12
TABLE 5-24:
Repeat Rate Enable Register
REPEAT RATE ENABLE REGISTER
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
28h
R/W
Repeat Rate
Enable
CS8_
RPT_EN
CS7_
RPT_EN
CS6_
RPT_EN
CS5_
RPT_EN
CS4_
RPT_EN
CS3_
RPT_EN
CS2_
RPT_EN
CS1_
RPT_EN
FFh
The Repeat Rate Enable register enables the repeat rate of the sensor inputs as described in Section 4.9.2, "Capacitive
Sensor Input Interrupt Behavior".
For all bits in this register:
• ‘0’ - The repeat rate for the specified sensor input is disabled. It will only generate an interrupt when a touch is
detected and when a release is detected (if enabled) no matter how long the touch is held.
• ‘1’ (default) - The repeat rate for the specified sensor input is enabled. In the case of a “touch” event, it will generate an interrupt when a touch is detected and a release is detected (as determined by the INT_REL_n bit - see
Section 5.6, "Configuration Registers"). In the case of a “press and hold” event, it will generate an interrupt when a
touch is detected and at the repeat rate so long as the touch is held.
Bit 7 - CS8_RPT_EN - Enables the repeat rate for capacitive touch sensor input 8.
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Bit 6 - CS7_RPT_EN - Enables the repeat rate for capacitive touch sensor input 7.
Bit 5 - CS6_RPT_EN - Enables the repeat rate for capacitive touch sensor input 6.
Bit 4 - CS5_RPT_EN - Enables the repeat rate for capacitive touch sensor input 5.
Bit 3 - CS4_RPT_EN - Enables the repeat rate for capacitive touch sensor input 4.
Bit 2 - CS3_RPT_EN - Enables the repeat rate for capacitive touch sensor input 3.
Bit 1 - CS2_RPT_EN - Enables the repeat rate for capacitive touch sensor input 2.
Bit 0 - CS1_RPT_EN - Enables the repeat rate for capacitive touch sensor input 1.
5.13
Signal Guard Enable Register
TABLE 5-25:
SIGNAL GUARD ENABLE REGISTER
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
29h
R/W
Signal
Guard
Enable
CS8_
SG_EN
CS7_
SG_EN
CS6_
SG_EN
-
CS4_
SG_EN
CS3_
SG_EN
CS2_
SG_EN
CS1_
SG_EN
00h
The Signal Guard Enable register enables the signal guard for the specified sensor inputs as described in Section 4.5.1,
"Signal Guard". When the signal guard is enabled, CS5 is disabled.
For all bits in this register:
• ‘0’ (default) - The signal guard is disabled for the specified sensor input.
• ‘1’ - The signal guard is enabled for the specified sensor input.
Bit 7 - CS8_SG_EN - Enables the signal guard for capacitive touch sensor input 8.
Bit 6 - CS7_SG_EN - Enables the signal guard for capacitive touch sensor input 7.
Bit 5 - CS6_SG_EN - Enables the signal guard for capacitive touch sensor input 6.
Bit 3 - CS4_SG_EN - Enables the signal guard for capacitive touch sensor input 4.
Bit 2 - CS3_SG_EN - Enables the signal guard for capacitive touch sensor input 3.
Bit 1 - CS2_SG_EN - Enables the signal guard for capacitive touch sensor input 2.
Bit 0 - CS1_SG_EN - Enables the signal guard for capacitive touch sensor input 1.
5.14
Multiple Touch Configuration Register
TABLE 5-26:
MULTIPLE TOUCH CONFIGURATION
Addr
R/W
Register
B7
B6
B5
B4
2Ah
R/W
Multiple Touch
Config
MULT_
BLK_
EN
-
-
-
B3
B2
B_MULT_T[1:0]
B1
B0
Default
-
-
80h
The Multiple Touch Configuration register controls the settings for the multiple touch detection circuitry. These settings
determine the number of simultaneous buttons that may be pressed before additional buttons are blocked and the MULT
status bit is set.
Bit 7 - MULT_BLK_EN - Enables the multiple button blocking circuitry.
• ‘0’ - The multiple touch circuitry is disabled. The device will not block multiple touches.
• ‘1’ (default) - The multiple touch circuitry is enabled. The device will flag the number of touches equal to programmed multiple touch threshold and block all others. It will remember which sensor inputs are valid and block all
others until that sensor pad has been released. Once a sensor pad has been released, the N detected touches
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(determined via the sensing cycle order of CS1 - CS8) will be flagged and all others blocked.
Bits 3 - 2 - B_MULT_T[1:0] - Determines the number of simultaneous touches on all sensor pads before a Multiple Touch
Event is detected and sensor inputs are blocked. The bit decode is given by Table 5-27.
TABLE 5-27:
B_MULT_T BIT DECODE
B_MULT_T[1:0]
Number of Simultaneous Touches
5.15
TABLE 5-28:
1
0
0
0
1 (default)
0
1
2
1
0
3
1
1
4
Multiple Touch Pattern Configuration Register
MULTIPLE TOUCH PATTERN CONFIGURATION
Addr
R/W
Register
B7
B6
B5
B4
2Bh
R/W
Multiple Touch
Pattern Config
MTP_ EN
-
-
-
B3
B2
MTP_TH[1:0]
B1
B0
Default
COMP_
PTRN
MTP_
ALERT
00h
The Multiple Touch Pattern Configuration register controls the settings for the multiple touch pattern detection circuitry.
This circuitry works like the multiple touch detection circuitry with the following differences:
1.
2.
3.
4.
The detection threshold is a percentage of the touch detection threshold as defined by the MTP_TH[1:0] bits
whereas the multiple touch circuitry uses the touch detection threshold.
The MTP detection circuitry either will detect a specific pattern of sensor inputs as determined by the Multiple
Touch Pattern register settings or it will use the Multiple Touch Pattern register settings to determine a minimum
number of sensor inputs that will cause the MTP circuitry to flag an event (see Section 5.16, "Multiple Touch Pattern Register"). When using pattern recognition mode, if all of the sensor inputs set by the Multiple Touch Pattern
register have a delta count greater than the MTP threshold or have their corresponding Noise Flag Status bits
set, the MTP bit will be set. When using the absolute number mode, if the number of sensor inputs with thresholds
above the MTP threshold or with Noise Flag Status bits set is equal to or greater than this number, the MTP bit
will be set.
When an MTP event occurs, all touches are blocked and an interrupt is generated.
All sensor inputs will remain blocked so long as the requisite number of sensor inputs are above the MTP threshold or have Noise Flag Status bits set. Once this condition is removed, touch detection will be restored. Note that
the MTP status bit is only cleared by writing a ‘0’ to the INT bit once the condition has been removed.
Bit 7 - MTP_EN - Enables the multiple touch pattern detection circuitry.
• ‘0’ (default) - The MTP detection circuitry is disabled.
• ‘1’ - The MTP detection circuitry is enabled.
Bits 3 - 2 - MTP_TH[1:0] - Determine the MTP threshold, as shown in Table 5-29. This threshold is a percentage of sensor input threshold (see Section 5.19, "Sensor Input Threshold Registers") for inputs enabled in the Active state or of
the standby threshold (see Section 5.24, "Standby Threshold Register") for inputs enabled in the Standby state.
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TABLE 5-29:
MTP_TH BIT DECODE
MTP_TH[1:0]
Threshold Divide Setting
1
0
0
0
12.5% (default)
0
1
25%
1
0
37.5%
1
1
100%
Bit 1 - COMP_PTRN - Determines whether the MTP detection circuitry will use the Multiple Touch Pattern register as a
specific pattern of sensor inputs or as an absolute number of sensor inputs.
• ‘0’ (default) - The MTP detection circuitry will use the Multiple Touch Pattern register bit settings as an absolute
minimum number of sensor inputs that must be above the threshold or have Noise Flag Status bits set. The number will be equal to the number of bits set in the register.
• ‘1’ - The MTP detection circuitry will use pattern recognition. Each bit set in the Multiple Touch Pattern register
indicates a specific sensor input that must have a delta count greater than the MTP threshold or have a Noise Flag
Status bit set. If the criteria are met, the MTP status bit will be set.
Bit 0 - MTP_ALERT - Enables an interrupt if an MTP event occurs. In either condition, the MTP status bit will be set.
• ‘0’ (default) - If an MTP event occurs, the ALERT# pin is not asserted.
• ‘1’ - If an MTP event occurs, the ALERT# pin will be asserted.
5.16
Multiple Touch Pattern Register
TABLE 5-30:
MULTIPLE TOUCH PATTERN REGISTER
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
2Dh
R/W
Multiple
Touch
Pattern
CS8_
PTRN
CS7_
PTRN
CS6_
PTRN
CS5_
PTRN
CS4_
PTRN
CS3_
PTRN
CS2_
PTRN
CS1_
PTRN
FFh
The Multiple Touch Pattern register acts as a pattern to identify an expected sensor input profile for diagnostics or other
significant events. There are two methods for how the Multiple Touch Pattern register is used: as specific sensor inputs
or number of sensor input that must exceed the MTP threshold or have Noise Flag Status bits set. Which method is used
is based on the COMP_PTRN bit (see Section 5.15). The methods are described below.
1.
2.
Specific Sensor Inputs: If, during a single sensing cycle, the specific sensor inputs above the MTP threshold or
with Noise Flag Status bits set match those bits set in the Multiple Touch Pattern register, an MTP event is
flagged.
Number of Sensor Inputs: If, during a single sensing cycle, the number of sensor inputs with a delta count above
the MTP threshold or with Noise Flag Status bits set is equal to or greater than the number of pattern bits set, an
MTP event is flagged.
For all bits in this register:
• ‘0’ - The specified sensor input is not considered a part of the pattern.
• ‘1’ - The specified sensor input is considered a part of the pattern, or the absolute number of sensor inputs that
must have a delta count greater than the MTP threshold or have the Noise Flag Status bit set is increased by 1.
Bit 7 - CS8_PTRN - Determines whether CS8 is considered as part of the Multiple Touch Pattern.
Bit 6 - CS7_PTRN - Determines whether CS7 is considered as part of the Multiple Touch Pattern.
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Bit 5 - CS6_PTRN - Determines whether CS6 is considered as part of the Multiple Touch Pattern.
Bit 4 - CS5_PTRN - Determines whether CS5 is considered as part of the Multiple Touch Pattern.
Bit 3 - CS4_PTRN - Determines whether CS4 is considered as part of the Multiple Touch Pattern.
Bit 2 - CS3_PTRN - Determines whether CS3 is considered as part of the Multiple Touch Pattern.
Bit 1 - CS2_PTRN - Determines whether CS2 is considered as part of the Multiple Touch Pattern.
Bit 0 - CS1_PTRN - Determines whether CS1 is considered as part of the Multiple Touch Pattern.
5.17
Base Count Out of Limit Register
TABLE 5-31:
BASE COUNT OUT OF LIMIT REGISTER
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
2Eh
R
Base Count
Out of Limit
BC_
OUT_
8
BC_
OUT_
7
BC_
OUT_
6
BC_
OUT_
5
BC_
OUT_
4
BC_
OUT_
3
BC_
OUT_
2
BC_
OUT_
1
00h
The Base Count Out of Limit Register indicates which sensor inputs have base counts out of limit (see Section 4.4, "Sensor Input Calibration"). When these bits are set, the BC_OUT bit is set (see Section 5.2, "Status Registers").
For all bits in this register:
• ‘0’ - The base count for the specified sensor input is in the operating range.
• ‘1’ - The base count of the specified sensor input is not in the operating range.
Bit 7 - BC_OUT_8 - Indicates whether CS8 has a base count out of limit.
Bit 6 - BC_OUT_7 - Indicates whether CS7 has a base count out of limit.
Bit 5 - BC_OUT_6 - Indicates whether CS6 has a base count out of limit.
Bit 4 - BC_OUT_5 - Indicates whether CS6 has a base count out of limit.
Bit 3 - BC_OUT_4 - Indicates whether CS6 has a base count out of limit.
Bit 2 - BC_OUT_3 - Indicates whether CS3 has a base count out of limit.
Bit 1 - BC_OUT_2 - Indicates whether CS2 has a base count out of limit.
Bit 0 - BC_OUT_1 - Indicates whether CS1 has a base count out of limit.
5.18
Recalibration Configuration Register
TABLE 5-32:
RECALIBRATION CONFIGURATION REGISTERS
Addr
R/W
Register
B7
B6
B5
2Fh
R/W
Recalibration
Configuration
BUT_
LD_TH
NO_CLR
_INTD
NO_CLR
_NEG
B4
B3
NEG_DELTA_
CNT[1:0]
B2
B1
B0
Default
CAL_CFG[2:0]
8Ah
The Recalibration Configuration register controls some recalibration routine settings (see Section 4.4, "Sensor Input
Calibration") as well as advanced controls to program the Sensor Input Threshold register settings.
Bit 7 - BUT_LD_TH - Enables setting all Sensor Input Threshold registers by writing to the Sensor Input 1 Threshold
register.
• ‘0’ - Each Sensor Input X Threshold register is updated individually.
• ‘1’ (default) - Writing the Sensor Input 1 Threshold register will automatically overwrite the Sensor Input Threshold
registers for all sensor inputs (Sensor Input Threshold 1 through Sensor Input Threshold 8). The individual Sensor
Input X Threshold registers (Sensor Input 2 Threshold through Sensor Input 8 Threshold) can be individually
updated at any time.
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Bit 6 - NO_CLR_INTD - Controls whether the accumulation of intermediate data is cleared if the noise status bit is set.
• ‘0’ (default) - The accumulation of intermediate data is cleared if the noise status bit is set.
• ‘1’ - The accumulation of intermediate data is not cleared if the noise status bit is set.
APPLICATION NOTE: Bits 5 and 6 should both be set to the same value. Either both should be set to ‘0’ or both
should be set to ‘1’.
Bit 5 - NO_CLR_NEG - Controls whether the consecutive negative delta counts counter is cleared if the noise status bit
is set.
‘0’ (default) - The consecutive negative delta counts counter is cleared if the noise status bit is set.
‘1’ - The consecutive negative delta counts counter is not cleared if the noise status bit is set.
Bits 4 - 3 - NEG_DELTA_CNT[1:0] - Determines the number of negative delta counts necessary to trigger a digital recalibration (see Section 4.4.2, "Negative Delta Count Recalibration"), as shown in Table 5-33.
TABLE 5-33:
NEG_DELTA_CNT BIT DECODE
NEG_DELTA_CNT[1:0]
Number of Consecutive Negative Delta Count Values
1
0
0
0
8
0
1
16 (default)
1
0
32
1
1
None (disabled)
Bits 2 - 0 - CAL_CFG[2:0] - Determines the update time and number of samples of the automatic recalibration routine
(see Section 4.4.1, "Automatic Recalibration"). The settings apply to all sensor inputs universally (though individual sensor inputs can be configured to support recalibration - see Section 5.10.1).
TABLE 5-34:
CAL_CFG BIT DECODE
CAL_CFG[2:0]
Recalibration Samples
(see Note 5-1)
Update Time (see
Note 5-2)
2
1
0
0
0
0
16
16
0
0
1
32
32
0
1
0
64
64 (default)
0
1
1
128
128
1
0
0
256
256
1
0
1
256
1024
1
1
0
256
2048
1
1
1
256
4096
Note 5-1
Recalibration Samples refers to the number of samples that are measured and averaged before the
Base Count is updated however does not control the base count update period.
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Note 5-2
5.19
Update Time refers to the amount of time (in sensing cycle periods) that elapses before the Base
Count is updated. The time will depend upon the number of channels enabled, the averaging setting,
and the programmed sensing cycle time.
Sensor Input Threshold Registers
TABLE 5-1:
SENSOR INPUT THRESHOLD REGISTERS
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
30h
R/W
Sensor Input 1
Threshold
-
64
32
16
8
4
2
1
40h
31h
R/W
Sensor Input 2
Threshold
-
64
32
16
8
4
2
1
40h
32h
R/W
Sensor Input 3
Threshold
-
64
32
16
8
4
2
1
40h
33h
R/W
Sensor Input 4
Threshold
-
64
32
16
8
4
2
1
40h
34h
R/W
Sensor Input 5
Threshold
-
64
32
16
8
4
2
1
40h
35h
R/W
Sensor Input 6
Threshold
-
64
32
16
8
4
2
1
40h
36h
R/W
Sensor Input 7
Threshold
-
64
32
16
8
4
2
1
40h
37h
R/W
Sensor Input 8
Threshold
-
64
32
16
8
4
2
1
40h
The Sensor Input Threshold registers store the delta threshold that is used to determine if a touch has been detected.
When a touch occurs, the input signal of the corresponding sensor pad changes due to the capacitance associated with
a touch. If the sensor input change exceeds the threshold settings, a touch is detected.
When the BUT_LD_TH bit is set (see Section 5.18 - bit 7), writing data to the Sensor Input 1 Threshold register will
update all of the Sensor Input Threshold registers (31h - 37h inclusive).
5.20
TABLE 5-2:
Sensor Input Noise Threshold Register
SENSOR INPUT NOISE THRESHOLD REGISTER
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
38h
R/W
Sensor Input
Noise Threshold
-
-
-
-
-
-
B1
B0
CS_BN_TH
[1:0]
Default
01h
The Sensor Input Noise Threshold register controls the value of a secondary internal threshold to detect noise and
improve the automatic recalibration routine. If a capacitive touch sensor input exceeds the Sensor Input Noise Threshold
but does not exceed the sensor input threshold, it is determined to be caused by a noise spike. That sample is not used
by the automatic recalibration routine. This feature can be disabled by setting the DIS_DIG_NOISE bit.
Bits 1-0 - CS1_BN_TH[1:0] - Controls the noise threshold for all capacitive touch sensor inputs, as shown in Table 5-3.
The threshold is proportional to the threshold setting.
 2013-2015 Microchip Technology Inc.
DS00001571B-page 45
CAP1298
TABLE 5-3:
CSX_BN_TH BIT DECODE
CS_BN_TH[1:0]
Percent Threshold Setting
5.21
1
0
0
0
25%
0
1
37.5% (default)
1
0
50%
1
1
62.5%
Standby Channel Register
TABLE 5-4:
STANDBY CHANNEL REGISTER
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
40h
R/W
Standby
Channel
CS8_
STBY
CS7_
STBY
CS6_
STBY
CS5_
STBY
CS4_
STBY
CS3_
STBY
CS2_
STBY
CS1_
STBY
00h
The Standby Channel register controls which (if any) capacitive touch sensor inputs are enabled in Standby (see Section
4.3.1.2, "Standby State Sensing Settings").
For all bits in this register:
• ‘0’ (default) - The specified channel will not be monitored in Standby.
• ‘1’ - The specified channel will be monitored in Standby. It will use the standby threshold setting, and the standby
averaging and sensitivity settings.
Bit 7 - CS8_STBY - Controls whether the CS8 channel is enabled in Standby.
Bit 6 - CS7_STBY - Controls whether the CS7 channel is enabled in Standby.
Bit 5 - CS6_STBY - Controls whether the CS6 channel is enabled in Standby.
Bit 4 - CS5_STBY - Controls whether the CS5 channel is enabled in Standby.
Bit 3 - CS4_STBY - Controls whether the CS4 channel is enabled in Standby.
Bit 2 - CS3_STBY - Controls whether the CS3 channel is enabled in Standby.
Bit 1 - CS2_STBY - Controls whether the CS2 channel is enabled in Standby.
Bit 0 - CS1_STBY - Controls whether the CS1 channel is enabled in Standby.
5.22
Standby Configuration Register
TABLE 5-5:
STANDBY CONFIGURATION REGISTER
Addr
R/W
Register
B7
41h
R/W
Standby
Configuration
AVG_
SUM
B6
B5
STBY_AVG[2:0]
B4
B3
B2
STBY_SAMP_
TIME[1:0]
B1
B0
STBY_CY_TIME
[1:0]
Default
39h
The Standby Configuration register controls averaging and sensing cycle time for sensor inputs enabled in Standby. This
register allows the user to change averaging and sample times on a limited number of sensor inputs in Standby and still
maintain normal functionality in the Active state.
DS00001571B-page 46
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CAP1298
Bit 7 - AVG_SUM - Determines whether the sensor inputs enabled in Standby will average the programmed number of
samples or whether they will accumulate for the programmed number of samples.
• ‘0’ - (default) - The Standby enabled sensor input delta count values will be based on the average of the programmed number of samples when compared against the threshold.
• ‘1’ - The Standby enabled sensor input delta count values will be based on the summation of the programmed
number of samples when compared against the threshold. Caution should be used with this setting as a touch
may overflow the delta count registers and may result in false readings.
Bits 6 - 4 - STBY_AVG[2:0] - Determines the number of samples that are taken for all Standby enabled channels during
the sensing cycle as shown in Table 5-6. All samples are taken consecutively on the same channel before the next channel is sampled and the result is averaged over the number of samples measured before updating the measured results.
TABLE 5-6:
STBY_AVG BIT DECODE
STBY_AVG[2:0]
Number Of Samples Taken Per
Measurement
2
1
0
0
0
0
1
0
0
1
2
0
1
0
4
0
1
1
8 (default)
1
0
0
16
1
0
1
32
1
1
0
64
1
1
1
128
Bit 3 - 2 - STBY_SAMP_TIME[1:0] - Determines the time to take a single sample for sensor inputs enabled in Standby
as shown in Table 5-7.
TABLE 5-7:
STBY_SAMP_TIME BIT DECODE
STBY_SAMP_TIME[1:0]
Sampling Time
1
0
0
0
320us
0
1
640us
1
0
1.28ms (default)
1
1
2.56ms
Bits 1 - 0 - STBY_CY_TIME[2:0] - Determines the desired sensing cycle time for sensor inputs enabled during Standby,
as shown in Table 5-8. This control is also used to determine programmed cycle time in the Combo state (see Section
4.3.1.3, "Combo State Sensing Settings"). All enabled channels are sampled at the beginning of the sensing cycle. If
additional time is remaining, the device is placed into a lower power state for the remainder of the sensing cycle.
 2013-2015 Microchip Technology Inc.
DS00001571B-page 47
CAP1298
TABLE 5-8:
STBY_CY_TIME BIT DECODE
STBY_CY_TIME[1:0]
Programmed Sensing Cycle Time
1
0
0
0
35ms
0
1
70ms (default)
1
0
105ms
1
1
140ms
APPLICATION NOTE: The programmed sensing cycle time (STDBY_CY_TIME[1:0] is only maintained if the actual
time to take the samples is less than the programmed cycle time. The STBY_AVG[2:0] bits
will take priority, so the sensing cycle time will be extended as necessary to accommodate
the number of samples to be measured.
5.23
TABLE 5-9:
Standby Sensitivity Register
STANDBY SENSITIVITY REGISTER
Addr
R/W
Register
B7
B6
B5
B4
B3
42h
R/W
Standby
Sensitivity
-
-
-
-
-
B2
B1
B0
STBY_SENSE[2:0]
Default
02h
The Standby Sensitivity register controls the sensitivity for sensor inputs enabled in Standby.
Bits 2 - 0 - STBY_SENSE[2:0] - Controls the sensitivity for sensor inputs that are enabled in Standby. The sensitivity
settings act to scale the relative delta count value higher or lower based on the system parameters. A setting of 000b is
the most sensitive while a setting of 111b is the least sensitive. At the more sensitive settings, touches are detected for
a smaller delta capacitance corresponding to a “lighter” touch. These settings are more sensitive to noise, however, and
a noisy environment may flag more false touches than higher sensitivity levels.
APPLICATION NOTE: A value of 128x is the most sensitive setting available. At the most sensitivity settings, the
MSB of the Delta Count register represents 64 out of ~25,000 which corresponds to a touch
of approximately 0.25% of the base capacitance (or a C of 25fF from a 10pF base
capacitance). Conversely a value of 1x is the least sensitive setting available. At these
settings, the MSB of the Delta Count register corresponds to a delta count of 8192 counts
out of ~25,000 which corresponds to a touch of approximately 33% of the base capacitance
(or a C of 3.33pF from a 10pF base capacitance).
TABLE 5-10:
STBY_SENSE BIT DECODE
STBY_SENSE[2:0]
Sensitivity Multiplier
2
1
0
0
0
0
128x (most sensitive)
0
0
1
64x
0
1
0
32x (default)
DS00001571B-page 48
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CAP1298
TABLE 5-10:
STBY_SENSE BIT DECODE (CONTINUED)
STBY_SENSE[2:0]
Sensitivity Multiplier
5.24
2
1
0
0
1
1
16x
1
0
0
8x
1
0
1
4x
1
1
0
2x
1
1
1
1x - (least sensitive)
Standby Threshold Register
TABLE 5-11:
STANDBY THRESHOLD REGISTER
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
43h
R/W
Standby
Threshold
-
64
32
16
8
4
2
1
40h
The Standby Threshold register stores the delta threshold that is used to determine if a touch has been detected. When
a touch occurs, the input signal of the corresponding sensor pad changes due to the capacitance associated with a
touch. If the sensor input change exceeds the threshold settings, a touch is detected.
5.25
Sensor Input Base Count Registers
TABLE 5-12:
SENSOR INPUT BASE COUNT REGISTERS
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
50h
R
Sensor Input 1
Base Count
128
64
32
16
8
4
2
1
C8h
51h
R
Sensor Input 2
Base Count
128
64
32
16
8
4
2
1
C8h
52h
R
Sensor Input 3
Base Count
128
64
32
16
8
4
2
1
C8h
53h
R
Sensor Input 4
Base Count
128
64
32
16
8
4
2
1
C8h
54h
R
Sensor Input 5
Base Count
128
64
32
16
8
4
2
1
C8h
55h
R
Sensor Input 6
Base Count
128
64
32
16
8
4
2
1
C8h
56h
R
Sensor Input 7
Base Count
128
64
32
16
8
4
2
1
C8h
57h
R
Sensor Input 8
Base Count
128
64
32
16
8
4
2
1
C8h
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DS00001571B-page 49
CAP1298
The Sensor Input Base Count registers store the calibrated “not touched” input value from the capacitive touch sensor
inputs. These registers are periodically updated by the calibration and recalibration routines.
The routine uses an internal adder to add the current count value for each reading to the sum of the previous readings
until sample size has been reached. At this point, the upper 16 bits are taken and used as the Sensor Input Base Count.
The internal adder is then reset and the recalibration routine continues.
The data presented is determined by the BASE_SHIFT[3:0] bits (see Section 5.5).
5.26
Power Button Register
TABLE 5-13:
POWER BUTTON REGISTER
Addr
R/W
Register
B7
B6
B5
B4
B3
60h
R/W
Power Button
-
-
-
-
-
B2
B1
B0
PWR_BTN[2:0]
Default
00h
The Power Button Register indicates the sensor input that has been designated as the power button (see Section 4.6,
"Power Button").
Bits 2 - 0 - PWR_BTN[2:0] - When the power button feature is enabled, this control indicates the sensor input to be used
as the power button. The decode is shown in Table 5-14.
TABLE 5-14:
PWR_BTN BIT DECODE
PWR_BTN[2:0]
Sensor Input Designated as Power Button
5.27
2
1
0
0
0
0
CS1
0
0
1
CS2
0
1
0
CS3
0
1
1
CS4
1
0
0
CS5
1
0
1
CS6
1
1
0
CS7
1
1
1
CS8
Power Button Configuration Register
TABLE 5-15:
POWER BUTTON CONFIGURATION REGISTER
Addr
R/W
Register
B7
B6
61h
R/W
Power Button
Configuration
-
STBY_
PWR_
EN
B5
B4
STBY_PWR_
TIME [1:0]
B3
B2
-
PWR_
EN
B1
B0
PWR_TIME [1:0]
Default
22h
The Power Button Configuration Register controls the length of time that the designated power button must indicate a
touch before an interrupt is generated and the power status indicator is set (see Section 4.6, "Power Button").
DS00001571B-page 50
 2013-2015 Microchip Technology Inc.
CAP1298
Bit 6 - STBY_PWR_EN - Enables the power button feature in the Standby state.
• ‘0’ (default) - The Standby power button circuitry is disabled.
• ‘1’ - The Standby power button circuitry is enabled.
Bits 5 - 4 - STBY_PWR_TIME[1:0] - Determines the overall time, as shown in Table 5-16, that the power button must
be held in the Standby state, in order for an interrupt to be generated and the PWR bit to be set.
Bit 2 - PWR_EN - Enables the power button feature in the Active state.
• ‘0’ (default) - The power button circuitry is disabled in the Active state.
• ‘1’ -The power button circuitry is enabled in the Active state.
Bits 1 - 0 - PWR_TIME[1:0] - Determines the overall time, as shown in Table 5-16, that the power button must be held
in the Active state, in order for an interrupt to be generated and the PWR bit to be set.
TABLE 5-16:
POWER BUTTON TIME BITS DECODE
PWR_TIME[1:0] / STBY_PWR_TIME[1:0]
Power Button Touch Hold Time
5.28
TABLE 5-17:
1
0
0
0
280ms
0
1
560ms
1
0
1.12 sec (default)
1
1
2.24 sec
Sensor Input Calibration Registers
SENSOR INPUT CALIBRATION REGISTERS
Addr
Register
R/W
B7
B6
B5
B4
B3
B2
B1
B0
Default
B1h
Sensor Input 1
Calibration
R
CAL1_9
CAL1_8
CAL1_7
CAL1_6
CAL1_5
CAL1_4
CAL1_3
CAL1_2
00h
B2h
Sensor Input 2
Calibration
R
CAL2_9
CAL2_8
CAL2_7
CAL2_6
CAL2_5
CAL2_4
CAL2_3
CAL2_2
00h
B3h
Sensor Input 3
Calibration
R
CAL3_9
CAL3_8
CAL3_7
CAL3_6
CAL3_5
CAL3_4
CAL3_3
CAL3_2
00h
B4h
Sensor Input 4
Calibration
R
CAL4_9
CAL4_8
CAL4_7
CAL4_6
CAL4_5
CAL4_4
CAL4_3
CAL4_2
00h
B5h
Sensor Input 5
Calibration
R
CAL5_9
CAL5_8
CAL5_7
CAL5_6
CAL5_5
CAL5_4
CAL5_3
CAL5_2
00h
B6h
Sensor Input 6
Calibration
R
CAL6_9
CAL6_8
CAL6_7
CAL6_6
CAL6_5
CAL6_4
CAL6_3
CAL6_2
00h
B7h
Sensor Input 7
Calibration
R
CAL7_9
CAL7_8
CAL7_7
CAL7_6
CAL7_5
CAL7_4
CAL7_3
CAL7_2
00h
B8h
Sensor Input 8
Calibration
R
CAL8_9
CAL8_8
CAL8_7
CAL8_6
CAL8_5
CAL8_4
CAL8_3
CAL8_2
00h
 2013-2015 Microchip Technology Inc.
DS00001571B-page 51
CAP1298
TABLE 5-17:
SENSOR INPUT CALIBRATION REGISTERS (CONTINUED)
Addr
Register
R/W
B7
B6
B5
B4
B3
B2
B1
B0
Default
B9h
Sensor Input
Calibration
LSB 1
R
CAL4_1
CAL4_0
CAL3_1
CAL3_0
CAL2_1
CAL2_0
CAL1_1
CAL1_0
00h
BAh
Sensor Input
Calibration
LSB 2
R
CAL8_1
CAL8_0
CAL7_1
CAL7_0
CAL6_1
CAL6_0
CAL5_1
CAL5_0
00h
The Sensor Input Calibration registers hold the 10-bit value that represents the last calibration value. The value represents the capacitance applied to the internal sensing circuits to balance the capacitance of the sensor input pad. Minimum (000h) and maximum (3FFh) values indicate analog calibration failure (see Section 4.4, "Sensor Input
Calibration").
5.29
Calibration Sensitivity Configuration Registers
TABLE 5-18:
CALIBRATION SENSITIVITY CONFIGURATION REGISTERS
Addr
Register
R/W
B7
B6
B5
B4
B3
B2
B1
B0
Default
80h
Calibration
Sensitivity
Config 1
R/W
CALSEN4[1:0]
CALSEN3[1:0]
CALSEN2[1:0]
CALSEN1[1:0]
00h
81h
Calibration
Sensitivity
Config 2
R/W
CALSEN8[1:0]
CALSEN7[1:0]
CALSEN6[1:0]
CALSEN5[1:0]
00h
CALSENx[1:0] - Controls the gain used by the calibration routine to enable sensor inputs to be more sensitive for proximity detection. Gain is based on capacitance touch pad capacitance ranges, as shown in Table 5-19. Since each sensor
input can have a different pad capacitance, each sensor input has a control.
TABLE 5-19:
CALSENX BIT DECODE
CALSENx[1:0]
5.30
Gain
Capacitive Touch Pad Capacitance
Range
1
0
0
0
1
5-50pF (default)
0
1
2
0-25pF
1
0
4
0-12.5pF
Product ID Register
TABLE 5-20:
PRODUCT ID REGISTER
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
FDh
R
Product ID
CAP1298
0
1
1
1
0
0
0
1
71h
DS00001571B-page 52
 2013-2015 Microchip Technology Inc.
CAP1298
The Product ID register stores a unique 8-bit value that identifies the device.
5.31
Manufacturer ID Register
TABLE 5-21:
VENDOR ID REGISTER
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
FEh
R
Manufacturer ID
0
1
0
1
1
1
0
1
5Dh
The Vendor ID register stores an 8-bit value that represents MCHP.
5.32
Revision Register
TABLE 5-22:
REVISION REGISTER
Addr
R/W
Register
B7
B6
B5
B4
B3
B2
B1
B0
Default
FFh
R
Revision
0
0
0
0
0
0
0
0
00h
The Revision register stores an 8-bit value that represents the part revision.
 2013-2015 Microchip Technology Inc.
DS00001571B-page 53
CAP1298
6.0
PACKAGE INFORMATION
6.1
CAP1298 Package Drawings
FIGURE 6-1:
Note:
CAP1298 14-LEAD PLASTIC SMALL OUTLINE, NARROW, 3.90 MM BODY (SOIC)
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
DS00001571B-page 54
 2013-2015 Microchip Technology Inc.
CAP1298
FIGURE 6-1:
Note:
CAP1298 14-LEAD PLASTIC SMALL OUTLINE, NARROW, 3.90 MM BODY (SOIC)
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
 2013-2015 Microchip Technology Inc.
DS00001571B-page 55
CAP1298
FIGURE 6-1:
1RWH
CAP1298 14-LEAD PLASTIC SMALL OUTLINE, NARROW, 3.90 MM BODY (SOIC)
)RUWKHPRVWFXUUHQWSDFNDJHGUDZLQJVSOHDVHVHHWKH0LFURFKLS3DFNDJLQJ6SHFLILFDWLRQORFDWHGDW
KWWSZZZPLFURFKLSFRPSDFNDJLQJ
DS00001571B-page 56
 2013-2015 Microchip Technology Inc.
CAP1298
FIGURE 6-2:
CAP1298 16-PIN QFN 3MM X 3MM
 2013-2015 Microchip Technology Inc.
DS00001571B-page 57
CAP1298
FIGURE 6-3:
DS00001571B-page 58
CAP1298 PACKAGE DIMENSIONS - 16-PIN QFN 3MM X 3MM
 2013-2015 Microchip Technology Inc.
CAP1298
FIGURE 6-4:
CAP1298 PCB LAND PATTERN AND STENCIL - 16-PIN QFN 3MM X 3MM
 2013-2015 Microchip Technology Inc.
DS00001571B-page 59
CAP1298
6.2
Package Marking
FIGURE 6-5:
CAP1298 PACKAGE MARKING
CAP1298Ͳ1ͲSLͲTR
3 6 WW
N N N A
Line1–DeviceCode,Week
Line2–AlphanumericTraceabilityCode
PbͲFreeJEDEC®designatorforMatteTin(Sn)
PIN1
CAP1298Ͳ2ͲSLͲTR
H 5 WW
N N N A
Line1–DeviceCode,Week
Line2–AlphanumericTraceabilityCode
PbͲFreeJEDEC®designatorforMatteTin(Sn)
PIN1
Line1–DeviceCode,Week
Line2–AlphanumericTraceabilityCode
3 6 WW
N N N A
2x0.6
e3
PBͲFREE/GREENSYMBOL
(Ni/PdPPͲLF)
PIN1
Lines1Ͳ2: CenterHorizontalAlignment
Line3: AsShown
BOTTOM
CAP1298Ͳ1ͲA4ͲTR
TOP
Bottommarkingnotallowed
TOP
H 5 WW
N N N A
2x0.6
e3
PBͲFREE/GREENSYMBOL
(Ni/PdPPͲLF)
PIN1
Lines1Ͳ2: CenterHorizontalAlignment
Line3: AsShown
BOTTOM
Bottommarkingnotallowed
DS00001571B-page 60
CAP1298Ͳ2ͲA4ͲTR
Line1–DeviceCode,Week
Line2–AlphanumericTraceabilityCode
 2013-2015 Microchip Technology Inc.
CAP1298
APPENDIX A:
A.1
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
DEVICE DELTA
Delta from CAP1128 / CAP1188 to CAP1298
Revision ID set to 00h.
Pinout changed. RESET, WAKE, and ADDR_COMM pins removed. LED pins removed. SPI pins / muxing also
removed. Added GND pin as ground slug is no longer used for ground connection.
Reduced package size from a 20-pin 4mm x 4mm QFN to a 16-pin 3mm x 3mm QFN.
Added Power Button feature (see Section 4.6, "Power Button").
Added ACAL_FAIL bit to flag analog calibration failures (see Section 5.2, "Status Registers") and ACAL_FAIL_INT bit to control analog calibration failure interrupts (see Section 5.6, "Configuration Registers").
Added BC_OUT bit to flag calibration failures regarding base counts out of limit (see Section 5.2, "Status Registers") and BC_OUT_RECAL and BC_OUT_INT bit to control base count out of limit behavior and interrupts (see
Section 5.6, "Configuration Registers"). Added Base Count Out of Limit Register to indicate which sensor inputs
have base counts outside the operating range (see Section 5.17, "Base Count Out of Limit Register").
New Combo state has been added which allows some sensors programmed to use the Active state settings and
other sensors programmed to use the Standby state settings to function at the same time (see Section 4.3.1.3,
"Combo State Sensing Settings").
Added an option for a signal guard that is overloaded with the CS5 pin. This signal guard is configured to power
a ground shield for improved signal in certain applications (see Section 4.5.1, "Signal Guard").
Increased supply voltage range for 5V operation.
Increased operating temperature range from 0°C - 85°C to -40°C to 125°C.
LEDs removed.
SMBus address fixed at 0101_000(r/w).
Removed SPI communications protocol option.
Removed RESET pin function.
Removed WAKE pin function.
Removed ALERT pin configuration.
Register set changes are shown in Table A-1, "Register Delta".
TABLE A-1:
REGISTER DELTA
Address
Register Delta
Delta
Default
00h
Page 26
Added bits - Main
Control Register
Added C_GAIN[1:0] and COMBO bits.
Changed function of GAIN[1:0] bits if
COMBO bit is set.
00h
02h
Page 28
Added bits - General
Status Register
Added bit 4 PWR for new Power Button
feature. Added bit 5 ACAL_FAIL to
indicate analog calibration failure. Added
bit 6 BC_OUT. Removed bit 4 LED
status.
00h
04h
Removed - LED Status
Register
removed register
n/a
20h
Page 32
Removed bit Configuration Register
Removed bit 6 WAKE_CFG.
20h
26h
Page 38
Renamed Calibration
Activate and Status
Register and added
functionality
In addition to forcing a calibration, the
register also indicates the status of
calibration for each sensor input.
00h
29h
Page 40
New - Signal Guard
Enable Register
new register for Signal Guard feature
00h
 2013-2015 Microchip Technology Inc.
DS00001571B-page 61
CAP1298
TABLE A-1:
REGISTER DELTA (CONTINUED)
Address
Register Delta
Delta
Default
2Eh
Page 43
New - Base Count Out
of Limit Register
new register for calibration status
00h
44h
Page 32
Added and removed
bits - Configuration 2
Register
Added bit 1 ACAL_FAIL_INT. Changed
bit 4 from BLK_POL_MIR to
BC_OUT_INT. Changed bit 6 from
ALT_POL to BC_OUT_RECAL.
Removed bit 7 INV_LINK_TRAN.
40h
60h
Page 50
New - Power Button
Register
new register for Power Button feature
00h
61h
Page 50
New - Power Button
Configuration Register
new register for configuring the Power
Button feature
00h
71h
Removed - LED Output
Type Register
removed register
n/a
72h
Removed - Sensor
Input LED Linking
Register
removed register
n/a
73h
Removed - LED
Polarity Register
removed register
n/a
74h
Removed - LED Output
Control Register
removed register
n/a
77h
Removed - Linked LED
Transition Control
Register
removed register
n/a
79h
Removed - LED Mirror
Control Register
removed register
n/a
80h
Page 52
Added - Calibration
Sensitivity Config 1
new register for proximity
00h
81h
Page 52
Changed - Calibration
Sensitivity Config 2
Changed from LED Behavior register to
new register for proximity
00h
82h
Removed - LED
Behavior Register 2
removed register
n/a
84h
Removed - LED Pulse
1 Period
removed register
n/a
85h
Removed - LED Pulse
2 Period
removed register
n/a
86h
Removed - LED
Breathe Period
Register
removed register
n/a
88h
Removed - LED Config
Register
removed register
n/a
90h
Removed - LED Pulse
1 Duty Cycle Register
removed register
n/a
91h
Removed - LED Pulse
2 Duty Cycle Register
removed register
n/a
DS00001571B-page 62
 2013-2015 Microchip Technology Inc.
CAP1298
TABLE A-1:
REGISTER DELTA (CONTINUED)
Address
Register Delta
Delta
Default
92h
Removed - LED
Breathe Duty Cycle
Register
removed register
n/a
93h
Removed - LED Direct
Duty Cycle Register
removed register
n/a
94h
Removed - LED Direct
Ramp Rates Register
removed register
n/a
95h
Removed - LED Off
Delay
removed register
n/a
FDh
Page 52
Changed - Product ID
New product ID for CAP1298
71h
FFh
Page 53
Changed - Revision
Register
Revision changed.
00h
 2013-2015 Microchip Technology Inc.
DS00001571B-page 63
CAP1298
7.0
REVISION HISTORY
TABLE 7-1:
REVISION HISTORY
Revision Level and Date
DS00001571B (08-25-15)
Section/Figure/Entry
Correction
Added 14-lead SOIC packages, SOIC pinout
diagrams, package marking.
Updated ordering information.
CAP1298 Revision A replaces the previous SMSC version Revision 1.0
DS00001571B-page 64
 2013-2015 Microchip Technology Inc.
CAP1298
THE MICROCHIP WEB SITE
Microchip provides online support via our WWW site at www.microchip.com. This web site is used as a means to make
files and information easily available to customers. Accessible by using your favorite Internet browser, the web site contains the following information:
• Product Support – Data sheets and errata, application notes and sample programs, design resources, user’s
guides and hardware support documents, latest software releases and archived software
• General Technical Support – Frequently Asked Questions (FAQ), technical support requests, online discussion
groups, Microchip consultant program member listing
• Business of Microchip – Product selector and ordering guides, latest Microchip press releases, listing of seminars and events, listings of Microchip sales offices, distributors and factory representatives
CUSTOMER CHANGE NOTIFICATION SERVICE
Microchip’s customer notification service helps keep customers current on Microchip products. Subscribers will receive
e-mail notification whenever there are changes, updates, revisions or errata related to a specified product family or
development tool of interest.
To register, access the Microchip web site at www.microchip.com. Under “Support”, click on “Customer Change Notification” and follow the registration instructions.
CUSTOMER SUPPORT
Users of Microchip products can receive assistance through several channels:
•
•
•
•
Distributor or Representative
Local Sales Office
Field Application Engineer (FAE)
Technical Support
Customers should contact their distributor, representative or field application engineer (FAE) for support. Local sales
offices are also available to help customers. A listing of sales offices and locations is included in the back of this document.
Technical support is available through the web site at: http://www.microchip.com/support
 2013-2015 Microchip Technology Inc.
DS00001571B-page 65
CAP1298
PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
PART NO.
[X]
Device
Address
Option
XX
-
Package
Device:
CAP1298
Tape and Reel
Option
TR
Tape and Reel
Package:(2)
A4
SL
16-pin QFN
14-pin SOIC
-
[XX]
Tape and Reel
Option
Examples:
a)
CAP1298-1-A4-TR
0b0101_000[r/w] Address
16-pin QFN package
b)
CAP1298-2-SL-TR
0b0101_001[r/w] Address
14-pin SOIC package
Note
DS00001571B-page 66
1:
Tape and Reel identifier only appears in the
catalog part number description. This identifier is used for ordering purposes and is
not printed on the device package. Check
with your Microchip Sales Office for package availability with the Tape and Reel
option.
2:
For other small form-factor package availability and marking information, please
visit www.microchip.com/packaging or
contact your local sales office.
 2013-2015 Microchip Technology Inc.
CAP1298
Note the following details of the code protection feature on Microchip devices:
•
Microchip products meet the specification contained in their particular Microchip Data Sheet.
•
Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
•
There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
•
Microchip is willing to work with the customer who is concerned about the integrity of their code.
•
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
Information contained in this publication regarding device applications and the like is provided only for your convenience and may be
superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO
REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR
OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE,
MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer’s risk, and the buyer agrees to defend, indemnify and hold
harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or
otherwise, under any Microchip intellectual property rights unless otherwise stated.
Trademarks
The Microchip name and logo, the Microchip logo, dsPIC, FlashFlex, flexPWR, JukeBlox, KEELOQ, KEELOQ logo, Kleer, LANCheck,
MediaLB, MOST, MOST logo, MPLAB, OptoLyzer, PIC, PICSTART, PIC32 logo, RightTouch, SpyNIC, SST, SST Logo, SuperFlash and
UNI/O are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries.
The Embedded Control Solutions Company and mTouch are registered trademarks of Microchip Technology Incorporated in the U.S.A.
Analog-for-the-Digital Age, BodyCom, chipKIT, chipKIT logo, CodeGuard, dsPICDEM, dsPICDEM.net, ECAN, In-Circuit Serial
Programming, ICSP, Inter-Chip Connectivity, KleerNet, KleerNet logo, MiWi, MPASM, MPF, MPLAB Certified logo, MPLIB, MPLINK,
MultiTRAK, NetDetach, Omniscient Code Generation, PICDEM, PICDEM.net, PICkit, PICtail, RightTouch logo, REAL ICE, SQI, Serial
Quad I/O, Total Endurance, TSHARC, USBCheck, VariSense, ViewSpan, WiperLock, Wireless DNA, and ZENA are trademarks of
Microchip Technology Incorporated in the U.S.A. and other countries.
SQTP is a service mark of Microchip Technology Incorporated in the U.S.A.
Silicon Storage Technology is a registered trademark of Microchip Technology Inc. in other countries.
GestIC is a registered trademark of Microchip Technology Germany II GmbH & Co. KG, a subsidiary of Microchip Technology Inc., in
other countries.
All other trademarks mentioned herein are property of their respective companies.
© 2013-2015, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved.
ISBN: 9781632776792
QUALITY MANAGEMENT SYSTEM
CERTIFIED BY DNV
== ISO/TS 16949 ==
 2013-2015 Microchip Technology Inc.
Microchip received ISO/TS-16949:2009 certification for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
Tempe, Arizona; Gresham, Oregon and design centers in California
and India. The Company’s quality system processes and procedures
are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping
devices, Serial EEPROMs, microperipherals, nonvolatile memory and
analog products. In addition, Microchip’s quality system for the design
and manufacture of development systems is ISO 9001:2000 certified.
DS00001571B-page 67
Worldwide Sales and Service
AMERICAS
ASIA/PACIFIC
ASIA/PACIFIC
EUROPE
Corporate Office
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-792-7200
Fax: 480-792-7277
Technical Support:
http://www.microchip.com/
support
Web Address:
www.microchip.com
Asia Pacific Office
Suites 3707-14, 37th Floor
Tower 6, The Gateway
Harbour City, Kowloon
China - Xiamen
Tel: 86-592-2388138
Fax: 86-592-2388130
Austria - Wels
Tel: 43-7242-2244-39
Fax: 43-7242-2244-393
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Tel: 86-756-3210040
Fax: 86-756-3210049
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Tel: 45-4450-2828
Fax: 45-4485-2829
India - Bangalore
Tel: 91-80-3090-4444
Fax: 91-80-3090-4123
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Tel: 33-1-69-53-63-20
Fax: 33-1-69-30-90-79
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Tel: 91-11-4160-8631
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Tel: 49-2129-3766400
Atlanta
Duluth, GA
Tel: 678-957-9614
Fax: 678-957-1455
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Tel: 852-2943-5100
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Australia - Sydney
Tel: 61-2-9868-6733
Fax: 61-2-9868-6755
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Tel: 86-10-8569-7000
Fax: 86-10-8528-2104
Austin, TX
Tel: 512-257-3370
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Tel: 86-28-8665-5511
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Tel: 774-760-0087
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Tel: 852-2943-5100
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Fax: 82-2-558-5932 or
82-2-558-5934
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Tel: 60-3-6201-9857
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Tel: 86-532-8502-7355
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Tel: 86-21-5407-5533
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Tel: 63-2-634-9065
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Fax: 86-24-2334-2393
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Tel: 65-6334-8870
Fax: 65-6334-8850
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Tel: 86-755-8864-2200
Fax: 86-755-8203-1760
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Tel: 886-3-5778-366
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Tel: 86-27-5980-5300
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Tel: 886-7-213-7828
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Tel: 86-29-8833-7252
Fax: 86-29-8833-7256
Canada - Toronto
Tel: 905-673-0699
Fax: 905-673-6509
Germany - Karlsruhe
Tel: 49-721-625370
Germany - Munich
Tel: 49-89-627-144-0
Fax: 49-89-627-144-44
Italy - Milan
Tel: 39-0331-742611
Fax: 39-0331-466781
Italy - Venice
Tel: 39-049-7625286
Netherlands - Drunen
Tel: 31-416-690399
Fax: 31-416-690340
Poland - Warsaw
Tel: 48-22-3325737
Spain - Madrid
Tel: 34-91-708-08-90
Fax: 34-91-708-08-91
Sweden - Stockholm
Tel: 46-8-5090-4654
UK - Wokingham
Tel: 44-118-921-5800
Fax: 44-118-921-5820
Taiwan - Taipei
Tel: 886-2-2508-8600
Fax: 886-2-2508-0102
Thailand - Bangkok
Tel: 66-2-694-1351
Fax: 66-2-694-1350
07/14/15
 2013-2015 Microchip Technology Inc.
DS00001571B-page 68
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