SMSC CAP1006 5 and 6 channel capacitive touch sensor Datasheet

CAP1005 / CAP1006
5 and 6 Channel Capacitive
Touch Sensor
PRODUCT FEATURES
Datasheet
General Description
Applications
The CAP1006 and CAP1005 are multiple channel
Capacitive Touch sensors. The CAP1006 contains six
(6) individual Capacitive Touch sensor inputs while the
CAP1005 contains five (5) sensors. Both devices offer
programmable sensitivity for use in touch sensor
applications. Each sensor automatically recalibrates to
compensate for gradual environmental changes.
„
„
„
„
Desktop and Notebook PC’s
LCD Monitors
Printers
Appliances
Features
„
„
The CAP1005 / CAP1006 offers multiple power states
operating at low quiescent currents.
Six (6) Capacitive Touch Sensor Inputs - CAP1006
Five (5) Capacitive Touch Sensor Inputs - CAP1005
— Programmable sensitivity
— Automatic recalibration
— Individual thresholds for each button
During the Standby mode of operation, one or more
Capacitive Touch Sensors are active.
„
„
Flexible Capacitive Touch Sense algorithm
Multiple Communication interfaces
— SMBus / I2C compliant interface (CAP1006-1 only)
— SMSC BC-Link interface (CAP1006-2 only)
— SPI communications (CAP1005 only)
The Deep Sleep mode of operation is the lowest power
state available drawing 3uA of current. During this
mode, no sensors are active. Communications will wake
the device.
„
Low Power operation
— 3uA quiescent current in Deep Sleep
— Samples one or more channels in Standby
— Open Drain or Push-Pull
„
Available in 10-pin 3mm x 3mm RoHS compliant DFN
package
CAP1006 Block Diagram
VDD
CAP1005 Block Diagram
VDD
GND
GND
2
SMCLK1 / BC_CLK
SMBus
Slave
Protocol
Capacitive Sensing Algorithm
1
SPI_CS#
2
SMDATA / BC_DATA
Capacitive Sensing Algorithm
SPI
Protocol
ALERT#1 / BC_IRQ#2
1
CS1
CS2
CS3
CS4
CS5
CS6
2
= CAP1006-1
= CAP1006-2
SPI_CLK
SPI_MOSI
SPI_MISO
CS1
CS2
CS3
CS4
CS5
Note: I2C is a trademark of NXP semiconductor. BC-Link is a trademark of SMSC.
SMSC CAP1005 / CAP1006
DATASHEET
Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
ORDERING INFORMATION
ORDERING NUMBER
PACKAGE
FEATURES
CAP1006-1-AIA-TR
10-pin DFN 3mm x 3mm
(Lead Free RoHS compliant)
Six Capacitive Touch Sensors, SMBus
interface
CAP1006-2-AIA-TR
10-pin DFN 3mm x 3mm
(Lead Free RoHS compliant)
Six Capacitive Touch Sensors, BC-Link
interface
CAP1005-1-AIA-TR
10-pin DFN 3mm x 3mm
(Lead Free RoHS compliant)
Five Capacitve Touch sensors, Full
Duplex SPI interface
REEL SIZE IS 4,000 PIECES
80 ARKAY DRIVE, HAUPPAUGE, NY 11788 (631) 435-6000, FAX (631) 273-3123
Copyright © 2009 SMSC or its subsidiaries. All rights reserved.
Circuit diagrams and other information relating to SMSC products are included as a means of illustrating typical applications. Consequently, complete information sufficient for
construction purposes is not necessarily given. Although the information has been checked and is believed to be accurate, no responsibility is assumed for inaccuracies. SMSC
reserves the right to make changes to specifications and product descriptions at any time without notice. Contact your local SMSC sales office to obtain the latest specifications
before placing your product order. The provision of this information does not convey to the purchaser of the described semiconductor devices any licenses under any patent
rights or other intellectual property rights of SMSC or others. All sales are expressly conditional on your agreement to the terms and conditions of the most recently dated
version of SMSC's standard Terms of Sale Agreement dated before the date of your order (the "Terms of Sale Agreement"). The product may contain design defects or errors
known as anomalies which may cause the product's functions to deviate from published specifications. Anomaly sheets are available upon request. SMSC products are not
designed, intended, authorized or warranted for use in any life support or other application where product failure could cause or contribute to personal injury or severe property
damage. Any and all such uses without prior written approval of an Officer of SMSC and further testing and/or modification will be fully at the risk of the customer. Copies of
this document or other SMSC literature, as well as the Terms of Sale Agreement, may be obtained by visiting SMSC’s website at http://www.smsc.com. SMSC is a registered
trademark of Standard Microsystems Corporation (“SMSC”). Product names and company names are the trademarks of their respective holders.
SMSC DISCLAIMS AND EXCLUDES ANY AND ALL WARRANTIES, INCLUDING WITHOUT LIMITATION ANY AND ALL IMPLIED WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE, AND AGAINST INFRINGEMENT AND THE LIKE, AND ANY AND ALL WARRANTIES ARISING FROM ANY COURSE
OF DEALING OR USAGE OF TRADE. IN NO EVENT SHALL SMSC BE LIABLE FOR ANY DIRECT, INCIDENTAL, INDIRECT, SPECIAL, PUNITIVE, OR CONSEQUENTIAL
DAMAGES; OR FOR LOST DATA, PROFITS, SAVINGS OR REVENUES OF ANY KIND; REGARDLESS OF THE FORM OF ACTION, WHETHER BASED ON CONTRACT;
TORT; NEGLIGENCE OF SMSC OR OTHERS; STRICT LIABILITY; BREACH OF WARRANTY; OR OTHERWISE; WHETHER OR NOT ANY REMEDY OF BUYER IS HELD
TO HAVE FAILED OF ITS ESSENTIAL PURPOSE, AND WHETHER OR NOT SMSC HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
Revision 1.1 (08-05-09)
2
DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Table of Contents
Chapter 1 Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Chapter 2 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Chapter 3 Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.1
3.2
3.3
3.4
3.5
3.6
Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1.1
SMBus (I2C) Communications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1.2
SPI Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1.3
BC-Link Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
System Management Bus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.1
SMBus Start Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.2
SMBus Address and RD / WR Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.3
SMBus Data Bytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.4
SMBus ACK and NACK Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.5
SMBus Stop Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.6
SMBus Timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.7
SMBus and I2C Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SMBus Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.1
SMBus Write Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.2
Block Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.3
SMBus Read Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.4
Block Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.5
SMBus Send Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.6
SMBus Receive Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPI Interface (CAP1005 only). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.1
SPI Normal Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.2
SPI_CS# Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.3
Address Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.4
SPI Timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Normal SPI Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.5.1
Reset Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.5.2
Set Address Pointer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.5.3
Write Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.5.4
Read Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BC-Link Interface (CAP1006-2 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13
13
13
13
13
14
14
14
14
14
14
14
15
15
15
16
16
16
16
17
17
17
17
18
18
19
20
20
21
22
Chapter 4 General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.1
4.2
4.3
Power States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Capacitive Touch Sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2.1
Sensing Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2.2
Recalibrating Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ALERT# Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3.1
Sensor Interrupt Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24
25
25
25
25
25
Chapter 5 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.1
5.2
5.3
5.4
5.5
5.6
Main Status Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Noise Flag Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sensor Delta Count Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sensitivity Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SMSC CAP1005 / CAP1006
3
DATASHEET
29
30
30
31
31
33
Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
5.7
5.8
5.9
5.10
5.11
5.12
5.13
5.14
5.15
5.16
5.17
5.18
5.19
5.20
5.21
5.22
5.23
5.24
5.25
Sensor Enable Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sensor Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sensor Configuration 2 Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Averaging and Sampling Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Calibration Activate Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interrupt Enable Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Repeat Rate Enable Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Multiple Touch Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recalibration Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sensor Threshold Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sensor Noise Threshold Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.17.1 Sensor Noise Threshold 1 Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.17.2 Sensor Noise Threshold 2 Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standby Channel Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standby Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standby Sensitivity Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standby Threshold Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sensor Base Count Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Product ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manufacturer ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
34
36
36
38
38
39
39
40
41
42
42
42
43
43
45
45
46
46
47
47
Chapter 6 Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
6.1
6.2
CAP1006 and CAP1005 Package Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Package Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Chapter 7 Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Revision 1.1 (08-05-09)
4
DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
List of Figures
Figure 1.1
Figure 1.2
Figure 3.1
Figure 3.1
Figure 3.1
Figure 3.2
Figure 3.3
Figure 3.4
Figure 3.5
Figure 3.6
Figure 4.1
Figure 4.2
Figure 4.3
Figure 4.4
Figure 6.1
Figure 6.2
Figure 6.3
Figure 6.4
Figure 6.5
Figure 6.6
CAP1006 Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
CAP1005 Pin Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
SMBus Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
SPI Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Example SPI Bus Communication - Normal Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
SPI Reset Interface Command - Normal Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
SPI Set Address Pointer Command - Normal Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
SPI Write Command - Normal Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
SPI Read Command - Normal Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
SPI Read Command - Normal Mode - Full . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
System Diagram for CAP1006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
System Diagram for CAP1005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Sensor Interrupt Behavior - Repeat Rate Enabled. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Sensor Interrupt Behavior - No Repeat Rate Enabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
10-Pin DFN 3mm x 3mm Package Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
10-Pin DFN 3mm x 3mm Package Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
10-Pin DFN 3mm x 3mm PCB Footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
CAP1006-1 Package Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
CAP1006-2 Package Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
CAP1005 Package Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
SMSC CAP1005 / CAP1006
5
DATASHEET
Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
List of Tables
Table 1.1 Pin Description for CAP1006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Table 1.2 Pin Description for CAP1005 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Table 1.3 Pin Types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Table 2.1 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Table 2.2 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Table 3.1 Protocol Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Table 3.2 Write Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Table 3.3 Block Write Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Table 3.4 Read Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 3.5 Block Read Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 3.6 Send Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 3.7 Receive Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 5.1 Register Set in Hexadecimal Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 5.2 Main Status Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 5.3 Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 5.4 Noise Flag Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 5.5 Sensor Delta Count Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 5.6 Sensitivity Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 5.7 DELTA_SENSE Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 5.8 BASE_SHIFT Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 5.9 Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 5.10 Sensor Enable Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 5.11 Sensor Configuration Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Table 5.12 MAX_DUR Bit Decode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 5.13 RPT_RATE Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 5.14 Sensor Configuration 2 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 5.15 Averaging and Sampling Configuration Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 5.16 AVG Bit Decode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 5.17 CYCLE_TIME Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 5.18 Calibration Activate Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Table 5.19 Interrupt Enable Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Table 5.20 Repeat Rate Enable Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Table 5.21 Multiple Touch Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Table 5.22 B_MULT_T Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Table 5.23 Recalibration Configuration Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Table 5.24 NEG_DELTA_CNT Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Table 5.25 CAL_CFG Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Table 5.26 Sensor Threshold Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Table 5.27 Sensor Noise Threshold Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Table 5.28 CSx_BN_TH Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Table 5.29 Standby Channel Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Table 5.30 Standby Configuration Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Table 5.31 STBY_AVG Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Table 5.32 STBY_CY_TIME Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Table 5.33 Standby Configuration Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Table 5.34 STBY_SENSE Bit Decode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Table 5.35 Standby Threshold Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Table 5.36 Sensor Base Count Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Table 5.37 Product ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Table 5.38 Vendor ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Table 5.39 Revision Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Table 7.1 Customer Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Revision 1.1 (08-05-09)
6
DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Chapter 1 Pin Description
CAP1006
3mm x 3mm DFN
CS1
1
10 CS2
ALERT# / BC_IRQ#
2
9
CS3
SMDATA / BC_DATA
3
8
CS4
SMCLK / BC_CLK
4
7
CS5
VDD
5
6
CS6
GND
Figure 1.1 CAP1006 Pin
Table 1.1 Pin Description for CAP1006
PIN
NUMBER
PIN NAME
PIN FUNCTION
PIN TYPE
1
CS1
Capacitive Touch Sensor 1
AIO
ALERT# - Active low alert / interrupt output usable for SMBus alert
(CAP1006-1)
OD (5V)
2
ALERT# /
BC_IRQ#
BC_IRQ# - Active low interrupt / optional for BC-Link
(CAP1006-2)
OD (5V)
SMDATA - Bi-directional, open-drain SMBus data - requires pull-up
resistor (CAP1006-1)
DIOD (5V)
BC_DATA - Bi-directional, open-drain BC-Link data - requires pullup resistor (CAP1006-2)
DIO
SMCLK - SMBus clock input - requires pull-up resistor
(CAP1006-1)
DI (5V)
BC_CLK - BC-Link clock input (CAP1006-2)
DI (5V)
3
4
SMDATA /
BC_DATA
SMCLK /
BC_CLK
5
VDD
Positive Power supply
Power
6
CS6
Capacitive Touch Sensor 6
AIO
7
CS5
Capacitive Touch Sensor 5
AIO
8
CS4
Capacitive Touch Sensor 4
AIO
9
CS3
Capacitive Touch Sensor 3
AIO
SMSC CAP1005 / CAP1006
7
DATASHEET
Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Table 1.1 Pin Description for CAP1006 (continued)
PIN
NUMBER
PIN NAME
PIN FUNCTION
PIN TYPE
10
CS2
Capacitive Touch Sensor 2
AIO
Bottom
Pad
GND
Ground
Power
CAP1005
3mm x 3mm DFN
SPI_CS#
1
10 CS1
SPI_MOSI
2
9
CS2
SPI_MISO
3
8
CS3
SPI_CLK
4
7
CS4
VDD
5
6
CS5
GND
Figure 1.2 CAP1005 Pin Diagram
Table 1.2 Pin Description for CAP1005
PIN
NUMBER
PIN NAME
PIN FUNCTION
PIN TYPE
1
SPI_CS#
Active low chip-select for SPI bus
DI (5V)
2
SPI_MOSI
SPI_MOSI - SPI Master-Out-Slave-In port
DI (5V)
3
SPI_MISO
SPI Master-In-Slave-Out data port
DO
4
SPI_CLK
SPI clock input
DI (5V)
5
VDD
Positive Power supply
Power
6
CS5
Capacitive Touch Sensor 5
AIO
7
CS4
Capacitive Touch Sensor 4
AIO
8
CS3
Capacitive Touch Sensor 3
AIO
9
CS2
Capacitive Touch Sensor 2
AIO
Revision 1.1 (08-05-09)
8
DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Table 1.2 Pin Description for CAP1005 (continued)
PIN
NUMBER
PIN NAME
PIN FUNCTION
PIN TYPE
10
CS1
Capacitive Touch Sensor 1
AIO
Bottom Pad
GND
Ground
Power
The pin types are described in detail below. All pins labeled with (5V) are 5V tolerant.
APPLICATION NOTE: For the 5V tolerant pins that have a pull-up resistor, the pull-up voltage must not exceed 3.6V
when the CAP1005 / CAP1006 is unpowered.
Table 1.3 Pin Types
PIN TYPE
DESCRIPTION
Power
SMSC CAP1005 / CAP1006
This pin is used to supply power or ground to the
device.
DI
Digital Input - This pin is used as a digital input. This
pin is 5V tolerant.
AIO
Analog Input / Output -This pin is used as an I/O for
analog signals.
DIOD
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.
OD
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.
DO
Push-pull Digital Output - This pin is used as a digital
output and can sink and source current.
DIO
Push-pull Digital Input / Output - This pin is used as an
I/O for digital signals.
9
DATASHEET
Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Chapter 2 Electrical Specifications
Table 2.1 Absolute Maximum Ratings
Voltage on 5V tolerant pins (V5VT_PIN)
-0.3 to 5.5
V
Voltage on 5V tolerant pins (|V5VT_PIN - VDD|) Note 2.2
0 to 3.6
V
Voltage on VDD pin
-0.3 to 4
V
Voltage on any other pin to GND
-0.3 to VDD + 0.3
V
Package Power Dissipation up to TA = 85°C for 10 pin DFN
(see Note 2.3)
0.7
W
Junction to Ambient (θJA)
77.7
°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 2.3mm thermal landing.
Table 2.2 Electrical Specifications
VDD = 3V to 3.6V, TA = 0°C to 100°C, all Typical values at TA = 27°C unless otherwise noted.
CHARACTERISTIC
SYMBOL
MIN
TYP
MAX
UNIT
CONDITIONS
DC Power
Supply Voltage
VDD
Supply Current
3.0
3.3
3.6
V
ISTBY
160
210
uA
Standby state active
1 sensor monitored
Default conditions (8 avg, 70ms
cycle time)
IDSLEEP
3
10
uA
Deep Sleep state active
No communications
TA < 85°C
IDD
300
500
uA
Average current
Capacitive Sensing Active
Capacitive Touch Sensor
Revision 1.1 (08-05-09)
10
DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Table 2.2 Electrical Specifications (continued)
VDD = 3V to 3.6V, TA = 0°C to 100°C, all Typical values at TA = 27°C unless otherwise noted.
CHARACTERISTIC
SYMBOL
Maximum Base
Capacitance
CBASE
Detectable
Capacitive Shift
ΔCTOUCH
MIN
TYP
MAX
50
0.1
2
UNIT
CONDITIONS
pF
Pad untouched
pF
Pad touched
I/O Pins - SPI_CS#, SPI_MOSI, and ALERT# pins
Output Low Voltage
VOL
Input High Voltage
VIH
Input Low Voltage
VIL
0.8
V
Leakage Current
ILEAK
±5
uA
0.4
2.0
V
ISINK_IO = 4mA
V
powered or unpowered
TA < 85°C
SMDATA / BC_DATA / SPI_MSIO / SPI_MISO and SMCLK / BC_CLK / SPI_CLK pins
0.4
V
ISINK_IO = 8mA
VDD 0.4
V
ISOURCE_IO = 8mA
2.0
V
Output Low Voltage
VOL
Output High Voltage
VOH
Input High Voltage
VIH
Input Low Voltage
VIL
0.8
V
Leakage Current
ILEAK
±5
uA
SMBus First
Communication
tSMB
15
ms
powered or unpowered
TA < 85°C
pull-up voltage < 3.6V
SMBus Timing (CAP1006-1 only)
5
pF
Input Capacitance
CIN
Clock Frequency
fSMB
Spike Suppression
tSP
Bus free time Start to
Stop
tBUF
1.3
us
Setup Time: Start
tSU:STA
0.6
us
Setup Time: Stop
tSU:STP
0.6
us
Data Hold Time
tHD:DAT
0.6
6
us
Data Setup Time
tSU:DAT
0.6
72
us
Clock Low Period
tLOW
1.3
us
Clock High Period
tHIGH
0.6
us
Clock/Data Fall time
tFALL
300
ns
Min = 20+0.1CLOAD ns
Clock/Data Rise time
tRISE
300
ns
Min = 20+0.1CLOAD ns
SMSC CAP1005 / CAP1006
10
400
kHz
50
ns
11
DATASHEET
Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Table 2.2 Electrical Specifications (continued)
VDD = 3V to 3.6V, TA = 0°C to 100°C, all Typical values at TA = 27°C unless otherwise noted.
CHARACTERISTIC
SYMBOL
Capacitive Load
CLOAD
MIN
TYP
MAX
UNIT
CONDITIONS
400
pF
per bus line
BC-Link Timing (CAP1006-2 only)
Clock Period
tCLK
250
ns
Data Hold Time
tHD:DAT
0
ns
Data Setup Time
tSU:DAT
30
ns
Clock Duty Cycle
Duty
40
50
60
Data must be valid before clock
%
SPI Timing (CAP1005 only)
Clock Period
tP
250
Clock Low Period
tLOW
0.4 x tP
0.6 x tP
ns
Clock High Period
tHIGH
0.4 x tP
0.6 x tP
ns
Clock Rise / Fall
time
tRISE /
tFALL
0.1 x tP
ns
Data Output Delay
tD:CLK
10
ns
Data Setup Time
tSU:DAT
20
ns
Data Hold Time
tHD:DAT
20
ns
SPI_CS# to
SPI_CLK setup time
tSU:CS
0
ns
Wake Time
tWAKE
10
Revision 1.1 (08-05-09)
ns
20
12
DATASHEET
us
SPI_CS# asserted to CLK assert
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Chapter 3 Communications
3.1
Communications
The CAP1006-1 communicates using the SMBus or I2C protocol. The CAP1006-2 communicates using
the 2-wire proprietary BC-Link protocol. The CAP1005 communicates using 4-wire SPI bus.
Regardless of the communications mechanism, the device functionality remains unchanged.
SMBus (I2C) Communications
3.1.1
When configured to communicate via the SMBus, the CAP1006 supports the following protocols: Send
Byte, Receive Byte, Read Byte, and Write Byte. In addition, the device supports I2C formatting for block
read and block write protocols.
See Section 3.2 and Section 3.3 for more information on the SMBus bus and protocols respectively.
3.1.2
SPI Communications
The CAP1005 is configured to communicate via SPI bus, using a 4-wire protocol. It does not support
the 3-wire protocol.
See Section 3.4 and Section 3.5 for more information on the SPI bus and protocols respectively.
3.1.3
BC-Link Communications
When BC-Link communications are used, the CAP1006 supports the read byte protocol and the write
byte protocol.
See Section 3.6 for more information on the BC-Link Bus and protocols respectively.
APPLICATION NOTE: Upon power up, the CAP1006 will not respond to any communications for up to 15ms. After
this time, full functionality is available.
3.2
System Management Bus
The CAP1006 communicates with a host controller, such as an SMSC SIO, through the SMBus. The
SMBus is a two-wire 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 CAP1006 will not stretch the clock signal.
TLOW
THIGH
THD:STA
TSU:STO
TRISE
SMCLK
THD:STA
THD:DAT
TFALL
TSU:STA
TSU:DAT
SMDATA
TBUF
P
S
S
S - Start Condition
P - Stop Condition P
Figure 3.1 SMBus Timing Diagram
SMSC CAP1005 / CAP1006
13
DATASHEET
Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
3.2.1
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.
The CAP1006-1 responds to SMBus address 0101_000(r/w).
3.2.3
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 CAP1006 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.
3.2.6
SMBus Timeout
The CAP1006 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).
3.2.7
SMBus and I2C Compliance
The major difference between SMBus and I2C devices is highlighted here. For complete compliance
information refer to the SMBus 2.0 specification.
1. Minimum frequency for SMBus communications is 10kHz.
2. The client protocol will reset if the clock is held low longer than 30ms.
3. The client protocol will reset if both the clock and the data line are high for longer than 150us (idle
condition).
4. I2C devices do not support the Alert Response Address functionality (which is optional for SMBus).
5. 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 CAP1006 supports I2C formatting only.
Revision 1.1 (08-05-09)
14
DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
3.3
SMBus Protocols
The CAP1006 is SMBus 2.0 compatible and supports Send Byte, Read Byte, Block Read, Receive
Byte as valid protocols as shown below. The CAP1006 also supports the I2C block read and block
write protocols. Finally, it will respond to the Alert Response Address protocol but is not in full
compliance.
All of the below protocols use the convention in Table 3.1.
Table 3.1 Protocol Format
DATA SENT
TO DEVICE
Data sent
3.3.1
DATA SENT TO
THE HOST
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
Block Write
The Block Write is used to write multiple data bytes to a group of contiguous registers as shown in
Table 3.3. It is an extension of the Write Byte Protocol.
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 3.3 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
SMSC CAP1005 / CAP1006
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DATASHEET
Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
3.3.3
SMBus Read Byte
The Read Byte protocol is used to read one byte of data from the registers as shown in Table 3.4.
Table 3.4 Read Byte Protocol
START
SLAVE
ADDRESS
1->0
0101_000
3.3.4
WR
ACK
REGISTER
ADDRESS
ACK
START
CLIENT
ADDRESS
0
0
XXh
0
1 ->0
0101_000
RD
1
ACK
0
REGISTER
DATA
XXh
NACK
1
STOP
0 -> 1
Block Read
The Block Read is used to read multiple data bytes from a group of contiguous registers as shown in
Table 3.5. It is an extension of the Read Byte Protocol.
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 3.5 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
0
XXh
0
XXh
0
XXh
0
...
XXh
1
0 -> 1
3.3.5
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 3.6.
Table 3.6 Send Byte Protocol
START
SLAVE
ADDRESS
WR
ACK
REGISTER
ADDRESS
ACK
STOP
1 -> 0
0101_000
0
0
XXh
0
0 -> 1
3.3.6
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 3.7.
Table 3.7 Receive Byte Protocol
START
SLAVE
ADDRESS
RD
ACK
REGISTER DATA
NACK
STOP
1 -> 0
0101_000
1
0
XXh
1
0 -> 1
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SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
3.4
SPI Interface (CAP1005 only)
The SMBus has a predefined packet structure, the SPI does not. The SPI Bus can operate in two
modes of operation, normal 4-wire mode and bi-directional 3-wire mode. The CAP1005 only supports
normal 4-wire mode. All SPI commands consist of 8-bit packets set to a specific slave device (identified
by the CS pin).
The SPI bus will latch data on the rising edge of the clock and the clock and data both idle high.
All commands are supported via both operating modes. The supported commands are: Reset Serial
interface, set address pointer, write command and read command. Note that all other codes received
during the command phase are ignored and have no effect on the operation of the device.
tP
tHIGH
tLOW
SPI_CLK
tFALL
tRISE
SPI_MSIO or
SPI_MOSI or
SPI_MISO
tSU:DAT
tD:CLK
tHD:DAT
Figure 3.1 SPI Timing
3.4.1
SPI Normal Mode
In the normal mode of operation, there are dedicated input and output data lines. The host
communicates by sending a command along the CAP1005 SPI_MOSI data line and reading data on
the SPI_MISO data line. Both communications occur simultaneously which allows for larger through
put of data transactions.
All basic transfers consist of two 8 bit transactions from the Master device while the slave device is
simultaneously sending data at the current address pointer value.
Data writes consist of two or more 8-bit transactions. The host sends a specific write command
followed by the data to write the address pointer. Data reads consist of one or more 8-bit transactions.
The host sends the specific read data command and continues clocking for as many data bytes as it
wishes to receive.
3.4.2
SPI_CS# Pin
The SPI Bus is a single master, multiple slave serial bus. Each slave has a dedicated CS pin (chip
select) that the master asserts low to identify that the slave is being addressed. There are no formal
addressing options.
3.4.3
Address Pointer
All data writes and reads are accessed from the current address pointer. In both Bi-directional mode
and Full Duplex mode, the Address pointer is automatically incremented following every read
command or every write command.
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The address pointer will return to 00h after reaching FFh.
3.4.4
SPI Timeout
The CAP1005 does not detect any timeout conditions on the SPI bus.
3.5
Normal SPI Protocols
When operating in normal mode, the SPI bus internal address pointer is incremented depending upon
which command has been transmitted. Multiple commands may be transmitted sequentually so long
as the SPI_CS# pin is asserted low. Figure 3.1 shows an example of this operation.
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DATASHEET
SMSC CAP1005 / CAP1006
SPI_MOSI
7Ah
7Ah
7Dh
41h
7Eh
66h
7Dh
41h
7Fh
7Fh
7Fh
7Fh
7Fh
7Fh
7Dh
40h
7Fh
7Fh
SPI_MISO
XXh
(invalid)
XXh
(invalid)
YYh
(invalid)
YYh
(invalid)
XXh
(invalid)
45h
AAh
(invalid)
AAh
(invalid)
55h
(invalid)
66h
AAh
AAh
55h
80h
43h
78h
XXh
(invalid)
56h
SPI Address Pointer
SPI Data output buffer
Register Address /
Data
41h
45h
00h
XXh
40h / 56h
41h / 45h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
46h / 78h
42h
AAh
41h
55h
41h
66h
42h
AAh
43h
55h
44h
80h
45h
43h
46h
78h
40h
80h
40h
56h
40h / 56h
41h / 45h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
40h / 56h
41h / 66h
42h / AAh
43h / 55h
44h / 80h
45h / 43h
46h / 78h
46h / 78h
46h / 78h
46h / 78h
46h / 78h
46h /78h
46h /78h
46h / 78h
46h /78h
Indicates SPI Address pointer incremented
19
DATASHEET
Figure 3.1 Example SPI Bus Communication - Normal Mode
3.5.1
Reset Interface
Resets the Serial interface whenever two successive 7Ah codes are received. Regardless of the current phase of the transaction - command or data,
the receipt of the successive reset commands resets the Serial communication interface only. All other functions are not affected by the reset operation.
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Revision 1.1 (08-05-09)
SPI_CS#
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
SPI_CS#
SPI_CLK
Master SPDOUT
SPI_MOSI
‘0’
‘1’
‘1’
‘1’
‘1’
‘0’
‘1’
‘0’
‘0’
Reset - 7Ah
‘1’
‘1’
‘1’
‘0’
‘1’
‘0’
Reset - 7Ah
Invalid register data
SPI_MISO
‘1’
00h – Internal Data buffer empty
Master Drives
Slave Drives
Figure 3.2 SPI Reset Interface Command - Normal Mode
3.5.2
Set Address Pointer
The Set Address Pointer command sets the Address pointer for subsequent reads and writes of data.
The pointer is set on the rising edge of the final data bit. At the same time, the data that is to be read
is fetched and loaded into the internal output buffer but is not transmitted.
SPI_CS#
SPI_CLK
Master SPDOUT
SPI_MOSI
‘0’
‘1’
‘1’
‘1’
‘1’
‘1’
‘0’
Register Address
‘1’
Set Address Pointer – 7Dh
Unknown, Invalid Data
Unknown, Invalid Data
SPI_MISO
Master Drives
Slave Drives
Address pointer set
Figure 3.3 SPI Set Address Pointer Command - Normal Mode
3.5.3
Write Data
The Write Data protocol updates the contents of the register referenced by the address pointer. As the
command is processed, the data to be read is fetched and loaded into the internal output buffer but
not transmitted. Then, the register is updated with the data to be written. Finally, the address pointer
is incremented.
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5 and 6 Channel Capacitive Touch Sensor
Datasheet
SPI_CS#
SPI_CLK
Master SPDOUT
SPI_MOSI
Write Command – 7Eh
SPI_MISO
Unknown, Invalid Data
Data to Write
Old Data at Current Address Pointer
Master Drives
Slave Drives
1. Data written at current
address pointer
2. Address pointer incremented
Figure 3.4 SPI Write Command - Normal Mode
3.5.4
Read Data
The Read Data protocol is used to read data from the device. During the normal mode of operation,
while the device is receiving data, the CAP1005 is simultaneously transmitting data to the host. For
the Set Address commands and the Write Data commands, this data may be invalid and it is
recommended that the Read Data command is used.
SPI_CS#
SPI_CLK
Master SPDOUT
SPI_MOSI
‘0’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
SPI_MISO
Invalid, Unknown Data *
Master Drives
‘0’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
Subsequent Read
Commands – 7F
First Read Command – 7Fh
Data at Current Address Pointer
Address Pointer
Incremented **
Slave Drives
* The first read command after any other command will return invalid data for the first
byte. Subsequent read commands will return the data at the Current Address Pointer
** The Address Pointer is incremented 8 clocks after the Read Command has been
received. Therefore continually sending Read Commands will result in each command
reporting new data. Once Read Commands have been finished, the last data byte will be
read during the next 8 clocks for any command
Figure 3.5 SPI Read Command - Normal Mode
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5 and 6 Channel Capacitive Touch Sensor
Datasheet
1. Register Read Address
updated to Current SPI Read
Address pointer.
2. Register Read Address
incremented = current address
pointer +1 – end result =
register address pointer doesn’t
change
1. Register Read Address
incremented = current address
pointer + 1
1. Register Read Address
updated to Current SPI Read
Address pointer
SPI_CS#
SPI_MISO
‘0’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
XXh
Read Command – 7Fh
Master SPDOUT
SPI_MOSI
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
Subsequent Read Commands – 7Fh
Data at previously set register address = current
SPI_CLK
address pointer
Master Drives
1. Output buffer transmitted =
data at previous address
1. Register data loaded into
pointer + 1 = current address
output buffer = data at current
pointer
address pointer
‘0’
Data at previously set register address = current
address pointer (SPI)
Data at previously set register address = current
address pointer (SPI)
Slave Drives
1. Output buffer transmitted =
data at current address pointer
+1
2. Flag set to increment SPI
Read Address at end of next 8
clocks
Register Data loaded into
1. Register data loaded into
Output buffer = data at current
output buffer = data at current
address pointer + 1
address pointer
1. SPI Read Address
Incremented = new current
1. Output buffer transmitted =
address pointer
data at current address pointer
2. Register Read Address
+1
Incremented = current address 1. Output buffer transmitted =
2. Flag set to increment SPI
data at previous register
pointer +1
Read Address at end of next 8
address pointer + 1 = current
clocks
address pointer
Figure 3.6 SPI Read Command - Normal Mode - Full
3.6
BC-Link Interface (CAP1006-2 only)
The BC-Link is a proprietary bus developed to allow communication between a host controller device
to a companion device. This device uses this serial bus to read and write registers and for interrupt
processing. The interface uses a data port concept, where the base interface has an address register,
data register and a control register, defined in the SMSC’s 8051’s SFR space.
Refer to documentation for the BC-Link comptabile host controller for details on how to access the
CAP1006 via the BC-Link Interface.
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DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Chapter 4 General Description
The CAP1006 / 1005 are multiple channel Capacitive Touch sensors. The CAP1006 contains six (6)
individual Capacitive Touch sensor inputs while the CAP1005 contains five (5) sensors. Both devices
offer programmable sensitivity for use in touch sensor applications. Each sensor automatically
recalibrates to compensate for gradual environmental changes.
The CAP1005 / CAP1006 offers multiple power states operating at low quiescent currents during its
Deep Sleep state. It can monitor one or more channels while in a lower power state and respond to
communications normally.
The device communicates with a host controller using the SPI bus (CAP1005 only), SMSC BC-Link
bus (CAP1006-2 only), or via SMBus / I2C (CAP1006-1 only). 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.
A typical system diagram for the CAP1006 is shown in Figure 4.1 and a system diagram for the
CAP1005 is shown in Figure 4.2.
SMDATA1 / BC_DATA2
SMCLK1 / BC_CLK2
ALERT#
Embedded Controller
VDD
CAP1006
Touch
Button
CS1
CS2
Touch
Button
Touch
Button
CS3
CS4
Touch
Button
Touch
Button
CS5
CS6
Touch
Button
1
2
= CAP1006-1
= CAP1006-2
Figure 4.1 System Diagram for CAP1006
SMSC CAP1005 / CAP1006
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Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
SPI_MOSI
SPI_MISO
SPI_CS#
SPI_CLK
Embedded Controller
VDD
CAP1005
Touch
Button
CS1
CS2
Touch
Button
Touch
Button
CS3
CS4
Touch
Button
Touch
Button
CS5
Figure 4.2 System Diagram for CAP1005
4.1
Power States
The CAP1005 / CAP1006 has three operating states depending on the status of the STBY and
DSLEEP bits. When the device transitions between power states, previously detected touches (for
inactive channels) are cleared and the status bits reset.
1. Fully Active - The device is fully active. It is monitoring all active Capacitive Sensor channels.
2. Standby - The device is in a lower power state. It will measure a programmable number of channels
(as determined by the Standby Channel register - default none). Interrupts will still be generated
based on the active channels. The device will still respond to communications normally and can
be returned to the Fully Active state of operation by clearing the STBY bit.
3. Deep Sleep - The device is in its lowest power state. It is not monitoring any Capacitive Sensor
channels. It can be awakened by SMBus or SPI communications targeting the device (which will
cause the DSLEEP bit to be automatically cleared).
APPLICATION NOTE: The CAP1006-2, which communicates using the BC-Link protocol, does not support Deep
Sleep.
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SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
4.2
Capacitive Touch Sensing
The CAP1005 / CAP1006 contains six (6) (CAP1006) or five (5) (CAP1005) independent Capacitive
Touch Sensor inputs. Each sensor has dynamic range to detect a change of capacitance due to a
touch. Additionally, each sensor can be configured to be automatically and routinely re-calibrated.
4.2.1
Sensing Cycle
Each Capacitive Touch Sensor has controls to be activated and included in the sensing cycle. When
the device is active, it automatically initiates a sensing cycle and repeats the cycle every time it
finishes. The cycle polls through each active Sensor starting with CS1 and extending through CS6. As
each Capacitive Touch Sensor is polled, its measurement is compared against a baseline “not touched”
measurement. If the delta measurement is large enough, then a touch is detected and an interrupt
generated.
The sensing cycle time is programmable (see Section 5.10).
4.2.2
Recalibrating Sensors
Each sensor is regularly recalibrated at an adjustable rate. By default, the recalibration routine stores
the average 256 previous measurements and periodically updates the base “Not Touched” setting for
the Capacitive Touch Sensor input.
It is possible that the device loses sensitivity to a touch. This may happen as a result of a noisy
environment, an accidental recalibration during a touch, or other environmental changes. When this
occurs, then the base untouched sensor may generate negative delta count values. The device will
detect this condition based on a programmable number of consecutive negative delta readings. When
it detects the condition, the CAP1005 / CAP1006 will automatically re-calibrate the base-count settings.
During this recalibration, the device will not respond to touches.
4.3
ALERT# Pin
The ALERT# pin is an active low output that is driven when an interrupt event is detected.
Whenever an interrupt is generated, the INT bit (see Section 5.1) is set. The ALERT# pin is cleared
when INT bit is cleared by the user. Additionally, when the INT bit is cleared by the user, status bits
are only cleared if no touch is detected.
4.3.1
Sensor Interrupt Behavior
The sensor interrupts are generated in one of two ways:
1. An interrupt is generated when a touch is detected and when a release is detected (see Figure 4.4).
2. If the repeat rate is enabled (see Section 5.6), then, so long as the touch is held, another interrupt
will be generated based on the programmed repeat rate (see Figure 4.3).
When the repeat rate is enabled, the device uses an additional control called MPRESS that determines
whether a touch is flagged as a simple “touch” or a “press and hold”. The MPRESS[3:0] bits set a
minimum press timer. When the button is touched the timer begins. If the sensor is released before
the minimum press timer expires, then it is flagged as a touch and an interrupt is generated upon the
release. If the sensor detects a touch for longer than this timer value, then 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 and upon a release.
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Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Interrupt on
Touch
Polling Cycle
(35ms)
Interrupt on
Release
Button Repeat Rate
(175ms)
Touch Detected
Button Repeat Rate
(175ms)
Button Repeat Rate
(175ms)
ALERT Pin / INT bit
Button Status
SMBus Write to INT bit
Figure 4.3 Sensor Interrupt Behavior - Repeat Rate Enabled
APPLICATION NOTE: The host may need to poll the device twice to determine that a release has been detected.
Interrupt on
Touch
Polling Cycle
(35ms)
Interrupt on
Release
Touch Detected
ALERT Pin /
INT bit
Button Status
SMBus Write to
INT bit
Figure 4.4 Sensor Interrupt Behavior - No Repeat Rate Enabled
Revision 1.1 (08-05-09)
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DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Chapter 5 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 Status Control
Controls general power states and
power dissipation
00h
Page 29
03h
R
Sensor Status
Returns the state of the sampeld
Capacative Touch Sensor
00h
Page 30
0Ah
R
Noise Flag Status
Stores the noise flags for sensors
00h
Page 30
10h
R
Sensor 1 Delta Count
Stores the delta count for CS1
00h
Page 31
11h
R
Sensor 2 Delta Count
Stores the delta count for CS2
00h
Page 31
12h
R
Sensor 3 Delta Count
Stores the delta count for CS3
00h
Page 31
13h
R
Sensor 4 Delta Count
Stores the delta count for CS4
00h
Page 31
14h
R
Sensor 5 Delta Count
Stores the delta count for CS5
00h
Page 31
15h
R
Sensor 6 Delta Count
Stores the delta count for CS6
00h
Page 31
1Fh
R/W
Sensitivity Control
Controls the sensitivity of the
threshold and delta counts and data
scaling of the base counts
2Fh
Page 31
20h
R/W
Configuration
Controls general functionality
20h
Page 33
21h
R/W
Sensor Enable
Controls whether the Capacitive
Touch Sensor inputs are sampled
3Fh
Page 33
22h
R/W
Sensor Configuration
Controls reset delay and auto-repeat
delay for sensors operating in the full
power state
A4h
Page 34
23h
R/W
Sensor Configuration
2
Controls the MPRESS controls for all
sensors
07h
Page 36
24h
R/W
Averaging and
Sampling Config
Controls averaging and sampling
window
1Dh
Page 36
26h
R/W
Calibration Activate
Activates manual re-calibration for
Capacative Touch Sensors
FFh
Page 38
27h
R/W
Interrupt Enable
Enables Interrupts associated with
Capacative Touch Sensors
3Fh
Page 38
28h
R/W
Repeat Rate Enable
Enables repeat rate for Capacative
Touch Sensors
3Fh
Page 39
2Ah
R/W
Multiple Press
Configuration
Determines the number of
simultaneous touches to flag a
multiple touch condition
80h
Page 39
2Fh
R/W
Recalibration
Configuration
Determines re-calibration timing and
sampling window
8Bh
Page 40
SMSC CAP1005 / CAP1006
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DATASHEET
Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Table 5.1 Register Set in Hexadecimal Order (continued)
REGISTER
ADDRESS
R/W
REGISTER NAME
FUNCTION
DEFAULT
VALUE
PAGE
30h
R/W
Sensor 1 Threshold
Stores the delta count threshold to
determine a touch for Capacitive
Touch Sensor 1
40h
Page 41
31h
R/W
Sensor 2 Threshold
Stores the delta count threshold to
determine a touch for Capacitive
Touch Sensor 2
40h
Page 41
32h
R/W
Sensor 3 Threshold
Stores the delta count threshold to
determine a touch for Capacitive
Touch Sensor 3
40h
Page 41
33h
R/W
Sensor 4 Threshold
Stores the delta count threshold to
determine a touch for Capacitive
Touch Sensor 4
40h
Page 41
34h
R/W
Sensor 5 Threshold
Stores the delta count threshold to
determine a touch for Capacitive
Touch Sensor 5
40h
Page 41
35h
R/W
Sensor 6 Threshold
Stores the delta count threshold to
determine a touch for Capacitive
Touch Sensor 6
40h
Page 41
38h
R/W
Sensor Noise
Threshold 1
Stores controls for selecting the
noise threshold for sensors 1 - 4
55h
Page 42
39h
R/W
Sensor Noise
Threshold 2
Stores controls for selecting the
noise threshold for sensors 5 - 6
55h
Page 42
Standby Configuration Registers
40h
R/W
Standby Channel
Controls which sensors are enabled
while in standby
00h
Page 43
41h
R/W
Standby Configuration
Controls averaging and cycle time
while in standby
1Dh
Page 43
42h
R/W
Standby Sensitivity
Controls sensitivity settings used
while in standby
02h
Page 45
43h
R/W
Standby Threshold
Stores the touch detection threshold
for active sensors in standby
40h
Page 45
50h
R
Sensor 1 Base Count
Stores the reference count value for
sensor 1
C8h
Page 46
51h
R
Sensor 2 Base Count
Stores the reference count value for
sensor 2
C8h
Page 46
52h
R
Sensor 3 Base Count
Stores the reference count value for
sensor 3
C8h
Page 46
53h
R
Sensor 4 Base Count
Stores the reference count value for
sensor 4
C8h
Page 46
54h
R
Sensor 5 Base Count
Stores the reference count value for
sensor 5
C8h
Page 46
55h
R
Sensor 6 Base Count
Stores the reference count value for
sensor 6
C8h
Page 46
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DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Table 5.1 Register Set in Hexadecimal Order (continued)
REGISTER
ADDRESS
R/W
FDh
DEFAULT
VALUE
REGISTER NAME
FUNCTION
Product ID
CAP1006
Stores a fixed value that identifies
each product
Product ID
CAP1005
Stores a fixed value that identifies
each product
45h
PAGE
44h
R
Page 46
FEh
R
Manufacturer ID
Stores a fixed value that identifies
SMSC
5Dh
Page 47
FFh
R
Revision
Stores a fixed value that represents
the revision number
81h
Page 47
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. Any reads to undefined registers will return 00h. Writes to
undefined registers will not have an effect.
5.1
Main Status Control Register
Table 5.2 Main Status Control Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
00h
R/W
Main Status
Control
-
-
STBY
DSLEEP
-
-
-
INT
00h
The Main Status and Control register controls the primary power state of the device.
Bit 5 - STBY - Enables Standby.
„
‘0’ (default) - Sensor scanning is active.
„
‘1’ - Capacitive Touch Sensor scanning is limited to the sensors set in the Standby Channel register
(see Section 5.18). The status registers will not be cleared until read. Sensors that are no longer
sampled will flag a release and then remain in a non-touched state.
Bit 4 - DSLEEP - Enables Deep Sleep by deactivating all functions. This bit will be cleared when SPI
or SMBus are received targeting the CAP1005 / CAP1006. If the CAP1005 / CAP1006 is configured
to communicate using the BC-Link protocol, then this bit is ignored.
„
‘0’ (default) - Sensor scanning is active.
„
‘1’ - All sensor scanning is disabled. The status registers are automatically cleared and the INT bit
is cleared.
Bit 0 - INT - Indicates that there is an interrupt. This bit is only set if the ALERT# pin has been asserted.
If a channel detects a touch and its associated interrupt enable bit is not set to a logic ‘1’ then 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. If the WAKE/SPI_MOSI pin
is asserted as a result of a touch detected while in Standby, it will likewise be deasserted when this
bit is cleared.
Note that this pin is not driven when communicating via the 4-wire SPI protocol
„
‘0’ - No interrupt pending.
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Datasheet
„
5.2
‘1’ - A touch has been detected on one or more channels and the interrupt has been asserted.
Status Registers
Table 5.3 Status Registers
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
03h
R
Sensor Status
-
-
CS6
CS5
CS4
CS3
CS2
CS1
00h
The Sensor Status Registers store 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 status bits are cleared when the device enters the Deep Sleep (DSLEEP = ‘1’ - see Section 5.1).
All status bits are cleared when the INT bit is cleared and if a touch on the respective Capacitive Touch
Sensor is no longer present. If a touch is still detected, then the bits will not be cleared (but this will
not cause the interrupt to be asserted - see Section 5.6).
Bit 5 - CS6 - Indicates that a touch was detected on Sensor 6.
Bit 4 - CS5 - Indicates that a touch was detected on Sensor 5.
Bit 3 - CS4 - Indicates that a touch was detected on Sensor 4.
Bit 2 - CS3 - Indicates that a touch was detected on Sensor 3.
Bit 1 - CS2 - Indicates that a touch was detected on Sensor 2.
Bit 0 - CS1 - Indicates that a touch was detected on Sensor 1.
5.3
Noise Flag Status Registers
Table 5.4 Noise Flag Status Registers
ADDR
R/W
REGISTER
0Ah
R
Noise Flag Status
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
-
-
CS6_
NOISE
CS5_
NOISE
CS4_
NOISE
CS3_
NOISE
CS2_
NOISE
CS1_
NOISE
00h
The Noise Flag Status registers store status bits that are generated from the analog block if the
detected noise is above the operating region of the analog detector. These bits indicate that the most
recently received data from the sensor is invalid and should not be used for touch detection.
Furthermore, so long as the bit is set for a particular channel, no decisions are made with the data. A
touch is not detected, and a release is not detected.
These bits are not sticky and will be cleared automatically if the analog block does not report a noise
error.
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5 and 6 Channel Capacitive Touch Sensor
Datasheet
5.4
Sensor Delta Count Registers
Table 5.5 Sensor Delta Count Registers
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
10h
R
Sensor 1 Delta
Count
Sign
64
32
16
8
4
2
1
00h
11h
R
Sensor 2 Delta
Count
Sign
64
32
16
8
4
2
1
00h
12h
R
Sensor 3 Delta
Count
Sign
64
32
16
8
4
2
1
00h
13h
R
Sensor 4 Delta
Count
Sign
64
32
16
8
4
2
1
00h
14h
R
Sensor 5 Delta
Count
Sign
64
32
16
8
4
2
1
00h
15h
R
Sensor 6 Delta
Count
Sign
64
32
16
8
4
2
1
00h
The Sensor 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
capacitor associated with a touch on one of the sensors and is referenced to a calibrated base “Not
touched” count value. The delta is an instantaneous change and is updated once per sensor per
sensing cycle (see Section 4.2.1 - sensor 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 FFh for negative delta counts which may result upon
a release.
5.5
Sensitivity Control Register
Table 5.6 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. 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 C 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 ΔC of 25fF from a 10pF base
capacitance). Conversely a value of 1x is the least sensitive setting available. At these
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5 and 6 Channel Capacitive Touch Sensor
Datasheet
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 ΔC of 3.33pF from a 10pF base capacitance).
Table 5.7 DELTA_SENSE Bit Decode
DELTA_SENSE[2:0]
2
1
0
SENSITIVITY MULTIPLIER
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 5.8 BASE_SHIFT Bit Decode
BASE_SHIFT[3:0]
3
2
1
0
DATA SCALING
FACTOR
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
256x
(default = 1111b)
All others
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5 and 6 Channel Capacitive Touch Sensor
Datasheet
5.6
Configuration Register
Table 5.9 Configuration Register
ADDR
R/W
REGISTER
B7
20h
R/W
Configuration
TIMEOUT
B6
B5
B4
B3
B2
B1
B0
DEFAULT
-
BLK_ DIG_
NOISE
BLK_ ANA_
NOISE
MAX_DUR_
EN
-
-
-
20h
The Configuration register controls general global functionality that affects the entire device.
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 150us. This is used for I2C compliance.
„
‘1’ - The SMBus timeout and idle functionality are enabled. The SMBus interface will time out 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 150us.
Bit 5 - BLK_DIG_NOISE - Determines whether the digital noise threshold is used by the device.
„
‘0’ - The digital noise threshold is used. If a delta count value exceeds the noise threshold but does
not exceed the touch threshold, then the sample is discarded and not used for the automatic recalibration routine.
„
‘1’ (default) - The noise threshold is not used. Any delta count that is less than the touch threshold
is used for the automatic re-calibration routine.
Bit 4 - BLK_ANA_NOISE - Determines whether the analog noise flag setting will block a touch
detection as well as the analog calibration routine.
„
‘0’ (default) - If the analog noise bit is set, then a touch is blocked on the corresponding channel
and will force the analog calibration routine to retry.
„
‘1’ - A touch is not blocked even if the analog noise bit is set. Likewise, the analog calibration
routine will not retry if the analog noise bit is set.
Bit 3 - MAX_DUR_EN - Determines whether the maximum duration recalibration is enabled for nongrouped sensors.
5.7
„
‘0’ (default) - The maximum duration recalibration functionality is disabled. A touch may be held
indefinitely and no re-calibration will be performed on any sensor.
„
‘1’ - The maximum duration recalibration functionality is enabled. If a touch is held for longer than
the MAX_DUR bit settings, then the re-calibration routine will be restarted (see Section 5.8).
Sensor Enable Registers
Table 5.10 Sensor Enable Registers
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
21h
R/W
Sensor Enable
-
-
CS6_EN
CS5_EN
CS4_EN
CS3_EN
CS2_EN
CS1_EN
3Fh
The Sensor Enable registers determine whether a Capacitive Touch Sensor input is included in the
sampling cycle. The length of the sampling cycle is not affected by the number of sensors measured.
Bit 5 - CS6_EN - Enables the CS6 input to be included during the sampling cycle.
„
‘0’ - The CS6 input is not included in the sampling cycle.
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Datasheet
„
‘1’ (default) - The CS6 input is included in the sampling cycle.
Bit 4 - CS5_EN - Enables the CS5 input to be included during the sampling cycle.
Bit 3 - CS4_EN - Enables the CS4 input to be included during the sampling cycle.
Bit 2 - CS3_EN - Enables the CS3 input to be included during the sampling cycle.
Bit 1 - CS2_EN - Enables the CS2 input to be included during the sampling cycle.
Bit 0 - CS1_EN - Enables the CS1 input to be included during the sampling cycle.
5.8
Sensor Configuration Register
Table 5.11 Sensor Configuration Register
ADDR
R/W
REGISTER
22h
R/W
Sensor
Configuration
B7
B6
B5
B4
MAX_DUR[3:0]
B3
B2
B1
RPT_RATE[3:0]
B0
DEFAULT
A4h
The Sensor Configuration Register controls timings associated with the Capacitive Sensor channels 1
- 6.
Bits 7 - 4 - MAX_DUR[3:0] - (default 1010b) - Determines the maximum time that a sensor is allowed
to be touched until the Capacitive Touch sensor is recalibrated as shown in Table 5.12.
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5 and 6 Channel Capacitive Touch Sensor
Datasheet
Table 5.12 MAX_DUR Bit Decode
MAX_DUR[3:0]
3
2
1
0
TIME BEFORE RECALIBRATION
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
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. The resolution is 35ms the range is from 35ms to 560ms as shown in
Table 5.13.
Table 5.13 RPT_RATE Bit Decode
RPT_RATE[3:0] OR M_PRESS[3:0]
3
2
1
0
INTERRUPT REPEAT RATE
OR M_PRESS TIME
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
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Datasheet
Table 5.13 RPT_RATE Bit Decode (continued)
RPT_RATE[3:0] OR M_PRESS[3:0]
3
2
1
0
INTERRUPT REPEAT RATE
OR M_PRESS TIME
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
5.9
Sensor Configuration 2 Register
Table 5.14 Sensor Configuration 2 Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
23h
R/W
Sensor
Configuration 2
-
-
-
-
B3
B2
B1
B0
M_PRESS[3:0]
DEFAULT
07h
Bits 3- 0 - M_PRESS[3:0] - (default 0111b) - Determines the minimum amount of time that sensors
configured to use auto repeat must detect a sensor touch to detect a “press and hold” event. If the
sensor detects a touch for longer than the M_PRESS[3:0] settings, then a “press and hold” event is
detected.
This is the maximum amount of time that sensors can detect a sensor touch to differentiate between
a “touch” and a “press and hold”. If a sensor detects a touch for less than or equal to the
M_PRESS[3:0] settings, then a touch event is detected.
The resolution is 35ms the range is from 35ms to 560ms as shown in Table 5.13.
5.10
Averaging and Sampling Configuration Register
Table 5.15 Averaging and Sampling Configuration Register
ADDR
R/W
REGISTER
24h
R/W
Averaging and
Sampling Config
B7
B6
B5
B4
AVG[2:0]
B3
B2
SAMP_
TIME
B1
B0
CYCLE_TIME
[1:0]
DEFAULT
1Dh
The Averaging and Sampling Configuration register controls the number of samples taken and the total
sensor cycle time for all active sensors while the device is functioning normally.
Bits 5 - 3 - AVG[2:0] - Determines the number of samples that are taken for all active channels during
the sensor cycle as shown in Table 5.16. All samples are taken consecutively on the same channel
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5 and 6 Channel Capacitive Touch Sensor
Datasheet
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 sensor cycle, and the AVG[2:0] bits are
set to take 4 samples per channel, then the full sensor cycle will be: CS1, CS1, CS1, CS1, CS2, CS2,
CS2, CS2, CS3, CS3, CS3, CS3.
Table 5.16 AVG Bit Decode
AVG[2:0]
2
1
0
NUMBER OF SAMPLES TAKEN
PER MEASUREMENT
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 2 - SAMP_TIME - Determines the time to take a single sample.
„
‘0’ - The sampling time is ~2.56ms.
„
‘1’ (default) - The sampling time is ~1.28ms.
Bits 1 - 0 - CYCLE_TIME[1:0] - Determines the overall cycle time for all measured channels during
normal operation as shown in Table 5.17. All measured channels are sampled at the beginning of the
cycle time. If additional time is remaining, then the device is placed into a lower power state for the
remaining duration of the cycle.
Table 5.17 CYCLE_TIME Bit Decode
CYCLE_TIME[1:0]
1
0
OVERALL CYCLE TIME
0
0
35ms
0
1
70ms (default)
1
0
105ms
1
1
140ms
APPLICATION NOTE: The programmed cycle time is only maintained if the total averaging time for all samples is
less than the programmed cycle. The AVG[2:0] bits will take priority so that if more samples
are required than would normally be allowed during the cycle time, the cycle time will be
extended as necessary to accommodate the number of samples to be measured.
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5 and 6 Channel Capacitive Touch Sensor
Datasheet
5.11
Calibration Activate Registers
Table 5.18 Calibration Activate Registers
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
26h
R/W
Calibration
Activate
-
-
CS6_CAL
CS5_CAL
CS4_CAL
CS3_CAL
CS2_CAL
CS1_CAL
FFh
The Calibration Activate register force the respective sensors to be re-calibrated. When a bit is set,
the corresponding Capacitive Touch Sensor will be re-calibrated and the bit will be automatically
cleared once the re-calibration routine has finished. During the re-calibration routine, the sensors will
not detect a press for up to 600ms and the Sensor Base Count register values will be invalid. During
this time, any press on the corresponding sensors will invalidate the re-calibration.
Bit 5 - CS6_CAL - When set, the CS6 input is re-calibrated. This bit is automatically cleared once the
sensor has been re-calibrated successfully.
Bit 4 - CS5_CAL - When set, the CS5 input is re-calibrated. This bit is automatically cleared once the
sensor has been re-calibrated successfully.
Bit 3 - CS4_CAL - When set, the CS4 input is re-calibrated. This bit is automatically cleared once the
sensor has been re-calibrated successfully.
Bit 2 - CS3_CAL - When set, the CS3 input is re-calibrated. This bit is automatically cleared once the
sensor has been re-calibrated successfully.
Bit 1 - CS2_CAL - When set, the CS2 input is re-calibrated. This bit is automatically cleared once the
sensor has been re-calibrated successfully.
Bit 0 - CS1_CAL - When set, the CS1 input is re-calibrated. This bit is automatically cleared once the
sensor has been re-calibrated successfully.
5.12
Interrupt Enable Register
Table 5.19 Interrupt Enable Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
27h
R/W
Interrupt
Enable
-
-
CS6_
INT_EN
CS5_
INT_EN
CS4_
INT_EN
CS3_
INT_EN
CS2_
INT_EN
CS1_
INT_EN
3Fh
The Interrupt Enable registers determine whether a sensor touch or release causes the interrupt pin
to be asserted.
Bit 5 - CS6_INT_EN - Enables the interrupt pin to be asserted if a touch is detected on CS6
(associated with the CS6 status bit).
„
‘0’ - The interrupt pin will not be asserted if a touch is detected on CS6 (associated with the CS6
status bit).
„
‘1’ (default) - The interrupt pin will be asserted a touch is detected on CS6 (associated with the
CS6 status bit).
Bit 4 - CS5_INT_EN - Enables the interrupt pin to be asserted if a touch is detected on CS5
(associated with the CS5 status bit).
Bit 3 - CS4_INT_EN - Enables the interrupt pin to be asserted if a touch is detected on CS4
(associated with the CS4 status bit).
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Datasheet
Bit 2 - CS3_INT_EN - Enables the interrupt pin to be asserted if a touch is detected on CS3
(associated with the CS3 status bit).
Bit 1 - CS2_INT_EN - Enables the interrupt pin to be asserted if a touch is detected on CS2
(associated with the CS2 status bit).
Bit 0 - CS1_INT_EN - Enables the interrupt pin to be asserted if a touch is detected on CS1
(associated with the CS1 status bit).
5.13
Repeat Rate Enable Register
Table 5.20 Repeat Rate Enable Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
28h
R/W
Repeat Rate
Enable
-
-
CS6_
RPT_EN
CS5_
RPT_EN
CS4_
RPT_EN
CS3_
RPT_EN
CS2_
RPT_EN
CS1_
RPT_EN
3Fh
The Repeat Rate Enable register determines the interrupt behavior of the buttons as described in
Section 4.3.1.
Bit 5 - CS6_RPT_EN - Enables the repeat rate for Capacitive Touch Sensor 6.
„
‘0’ - The repeat rate for CS6 is disabled. It will only generate an interrupt when a touch is detected
and when a release is detected no matter how long the touch is held for.
„
‘1’ (default) - The repeat rate for CS6 is enabled. In the case of a “touch” event, it will generate an
interrupt when a touch is detected and a release is detected. 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. It will not generate an interrupt when a release is detected.
Bit 4 - CS5_RPT_EN - Enables the repeat rate for Capacitive Touch Sensor 5.
Bit 3 - CS4_RPT_EN - Enables the repeat rate for Capacitive Touch Sensor 4.
Bit 2 - CS3_RPT_EN - Enables the repeat rate for Capacitive Touch Sensor 3.
Bit 1 - CS2_RPT_EN - Enables the repeat rate for Capacitive Touch Sensor 2.
Bit 0 - CS1_RPT_EN - Enables the repeat rate for Capacitive Touch Sensor 1.
5.14
Multiple Touch Configuration Register
Table 5.21 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 action is
taken.
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 accept the number of touches
equal to programmed multiple touch threshold and block all others. It will remember which sensor
is valid and block all others until that sensor has been released.
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5 and 6 Channel Capacitive Touch Sensor
Datasheet
Bits 3 - 2 - B_MULT_T[1:0] - Determines the number of simultaneous touches on all sensors before a
Multiple Touch Event is detected and sensors are blocked. The bit decode is given by Table 5.22.
Table 5.22 B_MULT_T Bit Decode
B_MULT_T[1:0]
5.15
1
0
NUMBER OF SIMULTANEOUS TOUCHES
0
0
1 (default)
0
1
2
1
0
3
1
1
4
Recalibration Configuration Register
Table 5.23 Recalibration Configuration Registers
ADDR
R/W
REGISTER
B7
B6
B5
2Fh
R/W
Recalibration
Configuration
BUT_
LD_TH
-
-
B4
B3
B2
NEG_DELTA_
CNT[1:0]
B1
B0
DEFAULT
CAL_CFG[2:0]
8Bh
The Recalibration Configuration register controls the automatic re-calibration routine settings as well
as advanced controls to program the Sensor Threshold register settings.
Bit 7 - BUT_LD_TH - Enables setting all Sensor Threshold registers by writing to the Sensor 1
Threshold register.
„
‘0’ - Each Sensor X Threshold register is updated individually.
„
‘1’ (default) - Writing the Sensor 1 Threshold register will automatically overwrite the Sensor
Threshold registers for all sensors (Sensor Threshold 1 through Sensor Threshold 6). The
individual Sensor X Threshold registers (Sensor 2 Threshold through Sensor 6 Threshold) can be
individually updated at any time.
Bits 4 - 3 - NEG_DELTA_CNT[1:0] - Determines the number of negative delta counts necessary to
trigger a digital re-calibration as shown in Table 5.24.
Table 5.24 NEG_DELTA_CNT Bit Decode
NEG_DELTA_CNT[1:0]
1
0
NUMBER OF CONSECUTIVE NEGATIVE DELTA
COUNT VALUES
0
0
8
0
1
16 (default)
1
0
32
1
1
None (disabled)
Revision 1.1 (08-05-09)
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DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Bits 2 - 0 - CAL_CFG[2:0] - Determines the update time and number of samples of the automatic recalibration routine. The settings applies to all sensors universally (though individual sensors can be
configured to support re-calibration - see Section 5.11).
Table 5.25 CAL_CFG Bit Decode
CAL_CFG[2:0]
2
1
0
RECALIBRATION
SAMPLES (SEE
Note 5.1)
0
0
0
16
16
0
0
1
32
32
0
1
0
64
64
0
1
1
256
256 (default)
1
0
0
256
1024
1
0
1
256
2048
1
1
0
256
4096
1
1
1
256
7936
5.16
UPDATE TIME (SEE
Note 5.2)
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.
Once this target number of update cycles is reached, the device may wait additional time
as determined by the Update Time before the base count is updated as determiend by the
settings.
Note 5.2
Update Time refers to the amount of time (in polling cycle periods) that elapses before the
Base Count is updated. For those settings that have the Update Time greater than the
Recalibration Samples value, the device will wait (and continue to average the updated
base count) until the Update Time has elapsed before the base count is updated.
Sensor Threshold Registers
Table 5.26 Sensor Threshold Registers
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
30h
R/W
Sensor 1
Threshold
-
64
32
16
8
4
2
1
40h
31h
R/W
Sensor 2
Threshold
-
64
32
16
8
4
2
1
40h
32h
R/W
Sensor 3
Threshold
-
64
32
16
8
4
2
1
40h
33h
R/W
Sensor 4
Threshold
-
64
32
16
8
4
2
1
40h
34h
R/W
Sensor 5
Threshold
-
64
32
16
8
4
2
1
40h
35h
R/W
Sensor 6
Threshold
-
64
32
16
8
4
2
1
40h
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Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
The Sensor 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 changes due to the
capacitance associated with a touch. If the sensor input change exceeds the threshold settings, then
a touch is detected.
When the BUT_LD_TH bit is set (see Section 5.15 - bit 7), writing data to the Sensor 1 Threshold
register will update all of the sensor threshold registers (31h - 37h inclusive).
5.17
Sensor Noise Threshold Registers
Table 5.27 Sensor Noise Threshold Registers
ADDR
R/W
REGISTER
38h
R/W
Sensor Noise
Threshold 1
39h
R/W
Sensor Noise
Threshold 2
B7
B6
CS4_BN_TH
[1:0]
0
1
B5
B4
CS3_BN_TH
[1:0]
0
1
B3
B2
B1
B0
DEFAULT
CS2_BN_TH
[1:0]
CS1_BN_TH
[1:0]
55h
CS6_BN_TH
[1:0]
CS5_BN_TH
[1:0]
55h
The Sensor Noise Threshold registers control the value of a secondary internal threshold to detect
noise and improve the automatic recalibration routine. If a Capacitive Touch Sensor output exceeds
the Sensor Noise Threshold but does not exceed the sensor threshold, then it is determined to be
caused by a noise spike. That sample is not used by the automatic re-calibration routine.
The Sensor Noise Threshold is proportional to the programmed threshold as shown in Table 5.28.
Table 5.28 CSx_BN_TH Bit Decode
CSX_BN_TH[1:0]
5.17.1
1
0
THRESHOLD DIVIDE SETTING
0
0
25%
0
1
37.5% (default)
1
0
50%
1
1
62.5%
Sensor Noise Threshold 1 Register
The Sensor Noise Threshold 1 register controls the noise threshold for Capacitive Touch Sensors 1-4.
Bits 7-6 - CS4_BN_TH[1:0] - Controls the noise threshold for Capacitive Touch Sensor 4.
Bits 5-4 - CS3_BN_TH[1:0] - Controls the noise threshold for Capacitive Touch Sensor 3.
Bits 3-2 - CS2_BN_TH[1:0] - Controls the noise threshold for Capacitive Touch Sensor 2.
Bits 1-0 - CS1_BN_TH[1:0] - Controls the noise threshold for Capacitive Touch Sensor 1.
5.17.2
Sensor Noise Threshold 2 Register
The Sensor Noise Threshold 2 register controls the noise threshold for Capacitive Touch Sensors 5 - 6.
Bits 3-2 - CS6_BN_TH[1:0] - Controls the noise threshold for Capacitive Touch Sensor 6.
Revision 1.1 (08-05-09)
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DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Bits 1-0 - CS5_BN_TH[1:0] - Controls the noise threshold for Capacitive Touch Sensor 5.
5.18
Standby Channel Register
Table 5.29 Standby Channel Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
40h
R/W
Standby
Channel
-
-
CS6_
STBY
CS5_
STBY
CS4_
STBY
CS3_
STBY
CS2_
STBY
CS1_
STBY
00h
The Standby Channel register controls which (if any) Capacitive Touch Sensors are active during
Standby.
Bit 5 - CS6_STBY - Controls whether the CS6 channel is active in Standby.
„
‘0’ (default) - The CS6 channel not be sampled during Standby mode.
„
‘1’ - The CS6 channel will be sampled during Standby Mode. It will use the Standby threshold
setting, and the standby averaging and sensitivity settings.
Bit 4 - CS5_STBY - Controls whether the CS5 channel is active in Standby.
Bit 3 - CS4_STBY - Controls whether the CS4 channel is active in Standby.
Bit 2 - CS3_STBY - Controls whether the CS3 channel is active in Standby.
Bit 1 - CS2_STBY - Controls whether the CS2 channel is active in Standby.
Bit 0 - CS1_STBY - Controls whether the CS1 channel is active in Standby.
5.19
Standby Configuration Register
Table 5.30 Standby Configuration Register
ADDR
R/W
REGISTER
B7
B6
41h
R/W
Standby
Configuration
AVG_
SUM
-
B5
B4
STBY_AVG[2:0]
B3
B2
STBY_
SAMP_
TIME
B1
B0
STBY_CY_TIME
[1:0]
DEFAULT
1Dh
The Standby Configuration register controls averaging and cycle time for those sensors that are active
in Standby.
Bit 7 - AVG_SUM - Determines whether the active sensors will average the programmed number of
samples or whether they will accumulate for the programmed number of samples.
„
‘0’ - (default) - The active sensor delta count values will be based on the average of the
programmed number of samples when compared against the threshold.
„
‘1’ - The active sensor delta count values will be based on the summation of the programmed
number of samples when compared against the threshold.
Bits 5 - 3 - STBY_AVG[2:0] - Determines the number of samples that are taken for all active channels
during the sensor cycle as shown in Table 5.31. 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.
SMSC CAP1005 / CAP1006
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DATASHEET
Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Table 5.31 STBY_AVG Bit Decode
STBY_AVG[2:0]
2
1
0
NUMBER OF SAMPLES TAKEN
PER MEASUREMENT
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 2 - STBY SAMP_TIME - Determines the time to take a single sample when the device is in Standby.
„
‘0’ - The sampling time is ~2.56ms.
„
‘1’ (default) - The sampling time is ~1.28ms.
Bits 1 - 0 - STBY_CY_TIME[2:0] - Determines the overall cycle time for all measured channels during
normal operation as shown in Table 5.17. All measured channels are sampled at the beginning of the
cycle time. If additional time is remaining, then the device is placed into a lower power state for the
remaining duration of the cycle.
Table 5.32 STBY_CY_TIME Bit Decode
STBY_CY_TIME[1:0]
1
0
OVERALL CYCLE TIME
0
0
35ms
0
1
70ms (default)
1
0
105ms
1
1
140ms
APPLICATION NOTE: The programmed cycle time is only maintained if the total averaging time for all samples is
less than the programmed cycle. The STBY_AVG[2:0] bits will take priority so that if more
samples are required than would normally be allowed during the cycle time, the cycle time
will be extended as necessary to accommodate the number of samples to be measured.
Revision 1.1 (08-05-09)
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DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
5.20
Standby Sensitivity Register
Table 5.33 Standby Configuration Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
42h
R/W
Standby
Sensitivity
-
-
-
-
-
B2
B1
B0
DEFAULT
STBY_SENSE[2:0]
02h
The Standby Sensitivity register controls the sensitivity for sensors that are active in Standby.
Bits 2 - 0 - STBY_SENSE[2:0] - Controls the sensitivity for sensors that are active 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 C 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 ΔC 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 ΔC of 3.33pF from a 10pF base capacitance).
Table 5.34 STBY_SENSE Bit Decode
STBY_SENSE[2:0]
5.21
2
1
0
SENSITIVITY MULTIPLIER
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)
Standby Threshold Register
Table 5.35 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
SMSC CAP1005 / CAP1006
45
DATASHEET
Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
The Standby Threshold registers 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 changes due to the
capacitance associated with a touch. If the sensor input change exceeds the threshold settings, then
a touch is detected.
5.22
Sensor Base Count Registers
Table 5.36 Sensor Base Count Registers
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
50h
R
Sensor 1 Base
Count
128
64
32
16
8
4
2
1
C8h
51h
R
Sensor 2 Base
Count
128
64
32
16
8
4
2
1
C8h
52h
R
Sensor 3 Base
Count
128
64
32
16
8
4
2
1
C8h
53h
R
Sensor 4 Base
Count
128
64
32
16
8
4
2
1
C8h
54h
R
Sensor 5 Base
Count
128
64
32
16
8
4
2
1
C8h
55h
R
Sensor 6 Base
Count
128
64
32
16
8
4
2
1
C8h
The Sensor Base Count registers store the calibrated “Not Touched” input value from the Capacitive
Touch Sensor inputs. These registers are periodically updated by the re-calibration routine.
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 Base Count. The internal adder is then reset and the re-calibration routine
continues.
The data presented is determined by the BASE_SHIFT[3:0] bits (see Section 5.5).
APPLICATION NOTE:
5.23
Product ID Register
Table 5.37 Product ID Register
ADDR
FDh
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
Product ID
CAP1006
0
1
0
0
0
1
0
0
44h
Product ID
CAP1005
0
1
0
0
0
1
0
1
45h
R
The Product ID register stores a unique 8-bit value that identifies the device.
Revision 1.1 (08-05-09)
46
DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
5.24
Manufacturer ID Register
Table 5.38 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 SMSC.
5.25
Revision Register
Table 5.39 Revision Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
FFh
R
Revision
1
0
0
0
0
0
0
1
81h
The Revision register stores an 8-bit value that represents the part revision.
SMSC CAP1005 / CAP1006
47
DATASHEET
Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Chapter 6 Package Information
6.1
CAP1006 and CAP1005 Package Drawings
Figure 6.1 10-Pin DFN 3mm x 3mm Package Drawing
Revision 1.1 (08-05-09)
48
DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Figure 6.2 10-Pin DFN 3mm x 3mm Package Dimensions
Figure 6.3 10-Pin DFN 3mm x 3mm PCB Footprint
SMSC CAP1005 / CAP1006
49
DATASHEET
Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
6.2
Package Marking
TOP
LINE 1: Device ID, First 2 of last 6 digits of
Lot Number
1 2
2x 0.6
LINE 2: Last 4 digits of Lot Number
e4
PB-FREE/GREEN SYMBOL
(Ni/Pd PP-LF)
PIN 1
LINES 1 & 2: CENTER HORIZONTAL ALIGNMENT
LINE 3: AS SHOWN
BOTTOM
BOTTOM MARKING IS NOT ALLOWED
Figure 6.4 CAP1006-1 Package Markings
TOP
LINE 1: Device ID, First 2 of last 6 digits of
Lot Number
1 3
2x 0.6
LINE 2: Last 4 digits of Lot Number
e4
PB-FREE/GREEN SYMBOL
(Ni/Pd PP-LF)
PIN 1
LINES 1 & 2: CENTER HORIZONTAL ALIGNMENT
LINE 3: AS SHOWN
BOTTOM
BOTTOM MARKING IS NOT ALLOWED
Figure 6.5 CAP1006-2 Package Markings
Revision 1.1 (08-05-09)
50
DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
TOP
LINE 1: Device ID, First 2 of last 6 digits of
Lot Number
1 1
2x 0.6
LINE 2: Last 4 digits of Lot Number
e4
PB-FREE/GREEN SYMBOL
(Ni/Pd PP-LF)
PIN 1
LINES 1 & 2: CENTER HORIZONTAL ALIGNMENT
LINE 3: AS SHOWN
BOTTOM
BOTTOM MARKING IS NOT ALLOWED
Figure 6.6 CAP1005 Package Markings
SMSC CAP1005 / CAP1006
51
DATASHEET
Revision 1.1 (08-05-09)
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Chapter 7 Revision History
Table 7.1 Customer Revision History
REVISION LEVEL & DATE
Rev. 1.1 (08-05-09)
SECTION/FIGURE/ENTRY
CORRECTION
Features
“TBD” replaced with “3uA” under Low Power
Operation
General Description
Deep sleep drawing “5uA” of current changed to
“3uA”
Table 2.2, "Electrical
Specifications"
Table updated:
- Current Measurement, ISTBY - changed the
typical column to 160, max to 210. Changed the
conditions to read: " Standby state active, one
sensor monitored, default conditions (8 avg, 70ms
cycle time)"
- Current Measurement, IDSLEEP -changed the
TYP column value to 3 and max to 10.
Rev. 1.0 (06-16-09)
Section 3.1.1, "SMBus (I2C)
Communications"
The following text deleted: “The SPI_CS# pin is not
used and any data presented to this pin will be
ignored.”
Section 6.2, "Package
Marking"
Updated package markings per new standards
Document title modified;
reel size added to ordering information;
updates to pinout, general description and register set.
“System RESET pin” removed from features
Rev. 0.56 (5/1/09)
Revision 1.1 (08-05-09)
Chapter 1, Pin Description
Pin tables modified adding SPI to “ALERT# /
BC_IRQ#” pin
Table 2.1, "Absolute
Maximum Ratings"
Notes following table modified
Figure 3.1, "SPI Timing"
Updated figure
Section 3.6, "BC-Link
Interface (CAP1006-2 only)"
Removed “8051” from 2nd paragraph
Chapter 4, General
Description
Second to last paragraph removed, not needed as
clarification follows
Section 4.1, "Power States"
Removed mention of LED driver outputs
Table 5.1, "Register Set in
Hexadecimal Order"
Updated text and register descriptions for incorrect
#’s Cap Sense channels
Section 6.2, "Package
Marking"
Updated package markings
General
Fixed typos and updated text as necessary.
Cleaned up system diagrams
Section 5.5, "Sensitivity
Control Register"
Renamed bit fields
52
DATASHEET
SMSC CAP1005 / CAP1006
5 and 6 Channel Capacitive Touch Sensor
Datasheet
Table 7.1 Customer Revision History (continued)
REVISION LEVEL & DATE
SECTION/FIGURE/ENTRY
CORRECTION
Section 5.6, "Configuration
Register"
Renamed bits 5 and 6
Rev. 0.53 (4/23/09)
Section 3.4, "SPI Interface
(CAP1005 only)"
Updated section to describe Normal operation
Rev. 0.52 (4/17/09)
General
Initial document creation
SMSC CAP1005 / CAP1006
53
DATASHEET
Revision 1.1 (08-05-09)
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