TI LMP92018SQE/NOPB Lmp92018 analog system monitor and controller Datasheet

LMP92018
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SNAS514B – NOVEMBER 2011 – REVISED MAY 2013
LMP92018 Analog System Monitor and Controller
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FEATURES
APPLICATIONS
•
•
•
•
1
2
•
•
•
•
•
8 ANALOG VOLTAGE MONITORING
CHANNELS
– 10-Bit ADC with Programmable Input MUX
– Internal/External Reference
– Tolerates High-Source Impedance at Lower
Sampling Rates
4 PROGRAMMABLE ANALOG VOLTAGE
OUTPUTS
– Four 10-Bit DACs
– Internal/External Reference
– Drives Loads up to 1nF
VOLTAGE REFERENCE
– User-Selectable Source: External or Internal
– Internal Reference 2.5V
TEMPERATURE SENSOR
– ±2.5°C Accuracy
12-BIT GPIO PORT
– Each Bit Individually Programmable
– User-Selectable Rail
SPI-COMPATIBLE BUS
– User-Selectable Rail
Communication Infrastructure
System Monitoring and Control
Industrial Monitoring and Control
DESCRIPTION
LMP92018 is a complete analog monitoring and
control circuit which integrates an eight channel 10-bit
Analog-to-Digital Converter (ADC), four 10-bit Digitalto-Analog Converters (DACs), an internal reference,
an internal temperature sensor, a12-bit GPIO port,
and a 10MHz SPI interface.
The eight channels of the ADC can be used to
monitor rail voltages, current sense amplifier outputs,
health monitors or sensors while the four DACs can
be used to control PA (Power Amplifier) bias points,
control actuators, potentiometers, etc.
Both the ADC and DACs can use either the internal
2.5V
reference
or
an
external
reference
independently allowing for flexibility in system design.
The built-in digital temperature sensor enables
accurate (±2.5°C) local temperature measurement
whose value is captured in the user accessible
register.
Block Diagram
IN[7:0]
OUT3
VDD
OUT0
8
DAC
DAC
DAC
DAC
Multiplexer
ADC
Temp. Sensor
Int/Ext
Ref
LMP92018
SPI
Interface
GPIO
4
12
REF
GPIO[11:0]
VGPIO
CSB
SCLK
DIN
DOUT
DRDYB
VIO
GND
1
2
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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LMP92018
SNAS514B – NOVEMBER 2011 – REVISED MAY 2013
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DESCRIPTION (CONTINUED)
The LMP92018 also includes a 12-bit GPIO port which allows for the resources of the microcontroller to be
further extended, thus providing even more flexibility and reducing the number of signal interfacing to the
microcontroller.
Both the GPIO port and the SPI compatible interface have independent supply pins enabling the LMP92018 to
interface with low voltage microcontrollers.
The LMP92018 is available in a space saving 36-pin WQFN package and is specified over the full -30°C to
+85°C temperature range.
Typical Application
5V
48V
5V
VDD
REF
IN[7:0]
Scaled
Voltage
Sensing
Ratiometric
Sensing
Voltage
Sense
Channels
8
LM94023
LMP8640
1.8V
Temp
VIO
Analog
Sensors
Current
sensing
ROUT<10k
DRDYB
SPI
4
Voltage
Source
+
-
LMP92018
uC
CSB
SCLK
DIN
DOUT
Servo
OUT[3:0]
Actuator
Control
Analog
Voltage
Control
4
PA
Bias
Control
3.3V
VGPIO
Digital
Control
GPIO[11:0]
Bidirectional
Digital Bus
12
Digital
Status
Indicators
2
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IN[7:0]
OUT3
VDD
OUT0
8
DAC
DAC
DAC
DAC
Multiplexer
ADC
Temp. Sensor
Int/Ext
Ref
LMP92018
SPI
Interface
GPIO
4
12
REF
GPIO[11:0]
VGPIO
CSB
SCLK
DIN
DOUT
DRDYB
VIO
GND
Overview
The LMP92018 has a flexible, feature-rich functionality which makes it ideally suited for many analog monitoring
and control applications, for example, base-station PA subsystems. This device provides the analog interface
between a programmable supervisor, such as a microcontroller, and an analog system whose behavior is to be
monitored and controlled by the supervisor.
To facilitate the analog monitoring functionality, the device contains a single 10-bit ADC preceded by a 8-input
multiplexor.
The analog control functionality is served by four 10-bit voltage output DACs.
Additional digital monitoring and control can be realized via the General Purpose I/O port GPIO[11:0].
Two more blocks are present for added functionality: a local temperature sensor and an internal reference
voltage generator.
8-CHANNEL ANALOG SENSE WITH 10-BIT ADC
The user can monitor up to 8 external voltages with the 10-bit ADC and its 8-channel input MUX. Typically these
voltages will be generated by the analog sensors, instrumentation amplifiers, current sense amplifiers, or simply
resistive dividers if high potentials need to be measured.
PROGRAMMABLE ANALOG CONTROL VOLTAGE OUTPUTS
Four identical individually programmable 10-bit DAC blocks are available to generate analog voltages, which can
be used to control bias conditions of external circuits, position of servos, etc.
INTERNAL DIGITAL TEMPERATURE SENSOR
An on-board digital temperature sensor is available to report the device's own temperature. The temperature
sensor output is stored in the internal register for user readback via the SPI interface.
INTERNAL VOLTAGE REFERENCE SOURCE
The user can choose to enable the internal reference of 2.5V to use with the ADC and/or DACs. The internal
reference source can also drive an external load.
12-BIT GENERAL PURPOSE I/O
The GPIO port can be used to expand the microcontroller capabilities. This port is memory mapped to the
internal register, which in turn is accessible via the SPI interface. Each bit is individually programmable as an
input or an output
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SPI INTERFACE
The microcontroller communicates with LMP92018 via a popular SPI interface. This interface provides the user
full access to all Data, Status and Control registers of the device.
REF
IN7
IN6
IN5
IN4
IN3
IN2
IN1
IN0
36
35
34
33
32
31
30
29
28
Connection Diagram
VDD
1
27
GPIO0
GND
2
26
GPIO1
GND
3
25
GPIO2
VGPIO
4
24
GPIO3
VIO
5
23
GPIO4
CSB
6
22
GPIO5
SCLK
7
21
GPIO6
DIN
8
20
GPIO7
DOUT
9
19
DRDYB
14
15
16
17
18
GPIO10
GPIO9
GPIO8
13
OUT0
GND
12
OUT1
GPIO11
11
10
OUT3
OUT2
DAP
Figure 1. 36-Pin WQFN (Top View)
See NJK0036A Package
PIN DESCRIPTIONS
Name
Pin
Function
VDD
1
Supply rail
VGPIO
4
GPIO rail
VIO
5
SPI rail
GND
2, 3 14
Device Ground
*
Die Attach Pad. For best thermal
conductivity and best noise immunity
DAP should be soldered to the PCB pad
which is connected directly to circuit
common node (GND).
DAP
ESD Structures
ESD+
ESD+
IN[7:0]
4
35:28
Analog input
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PIN DESCRIPTIONS (continued)
Name
Pin
Function
OUT[3:0]
10:13
Analog output
DOUT
9
SPI Data Output
GPIO[11:0]
15:18; 20:27
General Purpose Digital I/O. Logic level
is referenced to VGPIO pin.
CSB
6
SPI Chip Select, Active LO
SCLK
7
SPI Data Clock
DIN
8
SPI Data Input
DRBYB
19
Data Ready, open-drain active LO
ESD Structures
ESD+
ESD+
REF
36
ADC/DAC Voltage Reference Input or
Output
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
Absolute Maximum Ratings (1) (2) (3)
VDD Relative to GND
−0.3V to 6.0V
VIO Relative to GND
−0.3V to VDD
VGPIO Relative to GND
−0.3V to VDD
Voltage between any 2 pins (4)
6.0V
Current in or out of any pin (4)
5mA
32mA, TA = 125°C
Current through VDD
44mA, TA = 85°C
Current through VGPIO
20mA, TA = 125°C
54mA, TA = 125°C
Current through GND
66mA, TA = 85°C
Junction Temperature
+150°C
−65°C to +150°C
Storage Temperature Range
Human Body Model
ESD Susceptibility (5)
2500V
Machine Model
200V
Charged Device Model
(1)
(2)
(3)
(4)
(5)
1500V
“Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur, including inoperability and degradation of
device reliability and/or performance. Functional operation of the device and/or non-degradation at the Absolute Maximum Ratings or
other conditions beyond those indicated in the Recommended Operating Conditions is not implied. The recommended Operating
Conditions indicate conditions at which the device is functional and the device should not be operated beyond such conditions.
All voltages are measured with respect to GND = 0V, unless otherwise specified.
If Military/Aerospace specified devices are required, please contact the TI Sales Office/Distributors for availability and specifications.
When the input voltage (VIN) at any pin exceeds power supplies (VIN < GND or VIN > VDD), the current at that pin must not exceed
5mA, and the voltage (VIN) at that pin relative to any other pin must not exceed 6.0V. See Pin Descriptions for additional details of input
circuit structures.
The Human Body Model (HBM) is a 100 pF capacitor charged to the specified voltage then discharged through a 1.5kΩ resistor into
each pin. The Machine Model (MM) is a 200 pF capacitor charged to specified voltage then discharged directly into each pin. The
Charged Device Model (CDM) is a specified circuit characterizing an ESD event that occurs when a device acquires charge through
some triboelectric (frictional) or electrostatic induction process and then abruptly touches a grounded object or surface.
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Operating Conditions (1) (2)
−40°C to 125°C
Operating Ambient Temperature
VDD Voltage Range
4.75V to 5.25V
VIO Voltage Range
1.8V to VDD
VGPIO Voltage Range
1.8V to VDD
DAC Output Load C
0nF to 1nF
θJA
25.2°C/W
θJC
2.4°C/W
(1)
(2)
“Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur, including inoperability and degradation of
device reliability and/or performance. Functional operation of the device and/or non-degradation at the Absolute Maximum Ratings or
other conditions beyond those indicated in the Recommended Operating Conditions is not implied. The recommended Operating
Conditions indicate conditions at which the device is functional and the device should not be operated beyond such conditions.
All voltages are measured with respect to GND = 0V, unless otherwise specified.
Electrical Characteristics
Unless otherwise noted, these specifications apply for VDD=4.75V to 5.25V, REF=VDD, TA=25°C. Boldface limits are over
the temperature range of −30°C ≤ TA ≤ 85°C unless otherwise noted. DAC input code range 12 to 1012. DAC output
CL = 200 pF unless otherwise noted.
Symbol
Parameter
Conditions
Min
Typ
Max
Units
10
10
Bits
−0.9
+1
ADC CHARACTERISTICS
Resolution with No Missing
Codes
DNL
Differential Non-Linearity
INL
Integral Non-Linearity
−1
1
OE
Offset Error
−2
+2
OEDRIFT
Offset Error Temperature Drift
OEMTCH
Offset Error Match (1)
−1
1
Gain Error
−2
2
GE
GEDRIFT
Gain Error Temperature Drift
GEMTCH
Gain Error Match (1)
SINAD
THD
SFDR
PSRR
Signal-to-Noise Ratio
Total Harmonic Distortion
Spurious Free Dynamic Range
Power Supply Rejection Ratio
0.001
LSB/°C
0.001
−1
10 kHz Sine Wave
58
10 kHz Sine Wave, up to 5th harmonic
−69
10 kHz Sine Wave
70
LSB
LSB
LSB/°C
1
LSB
dB
dBc
Offset Error change with VDD
−150
Gain Error change with VDD
−150
dB
DAC CHARACTERISTICS
10
RL = 100k
−0.5
+0.5
Integral Non-Linearity
RL = 100k
−2
+2
OE
Offset Error (2)
RL = 100k
Offset Error Temperature Drift
FSE
Full-Scale Error
GE
Gain Error (3)
Gain Error Temperature Drift
Zero Code Output
Bits
Bits
Differential Non-Linearity
ZCO
6
10
INL
GEDRIFT
(3)
10
Monotonicity
DNL
OEDRIFT
(1)
(2)
Resolution
LSB
10
RL = 100k
1
µV/°C
VDD = 5.25V, REF=5, RL = 100k,
CODE=3FFh
-0.4
+0.3
RL = 100k
−0.2
+0.2
RL = 100k
1.4
IOUT = 200 µA
7
IOUT = 1mA
31
mV
%FS
ppm/° C
mV
Device Specification is guaranteed by characterization and is not tested in production.
DAC Offset is the y-intercept of the straight line defined by DAC output at code 0d12 and 0d1011points of the measured transfer
characteristic.
DAC Gain Error is the difference in slope of the straight line defined by DAC output at code 0d12 and 0d1011 points of transfer
characteristic, and that of the ideal characteristic.
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Electrical Characteristics (continued)
Unless otherwise noted, these specifications apply for VDD=4.75V to 5.25V, REF=VDD, TA=25°C. Boldface limits are over
the temperature range of −30°C ≤ TA ≤ 85°C unless otherwise noted. DAC input code range 12 to 1012. DAC output
CL = 200 pF unless otherwise noted.
Symbol
FSO
Parameter
Full Scale Output at code 3FFh
Conditions
Min
IOUT = 200 µA
4.975
IOUT = 1mA
4.975
RL = 100k
4.975
Typ
Max
Units
V
IOS
Output Short Circuit Current
(Source) (4)
VDD = 5V, OUT = 0V,
Input Code =3 FFh
−67
IOS
Output Short Circuit Current
(Sink) (4)
VDD = 5V, OUT = DREF,
Input Code = 000h
76
IO
Continuous Output Current per
Channel (to prevent damage)
TA = 85° C
10
TA = 125° C
6.5
CL
Maximum Load Capacitance
RL = 2k or ∞
1000
Enabled
1.7
Ω
Disabled
>20
MΩ
ROUT
DC Output Impedance
mA
pF
ANALOG INPUT CHARACTERISTICS
VIN
FS Input Range
ILEAK
ADC in HOLD or Power Down
CINA
Input Capacitance
−1
In Acquisition mode
33
In Conversion mode
3
REF
V
+1
µA
pF
REFERENCE CHARACTERISTICS
ADC Reference Input Range
2.5
VDD
DAC Reference Input Range
2.5
VDD
DAC Reference Input Resistance
50
DAC Reference Input Current
IVREF(ADC)
ADC Reference Current, during
conversion, average value
IVREF(PD)
REF pin Current in Powerdown
V
External Reference, REF = VDD
REF Output Voltage
kΩ
125
µA
1
µA
10
µA
2.5
Internal Reference Tolerance
–0.15
V
0.15
%
REF Output Temperature Drift
17
ppm/°C
REF Output Maximum Current
1
mA
REF Output Load Regulation
REF Output Rail Regulation
–0.6
4.75V≤VDD≤5.25V
%
±0.04
%
0.0625
°C
TEMPERATURE SENSOR
Resolution
Temperature Error
(5)
−40°C to +125°C
−2.5
+2.5
°C
0.3x
VGPIO
V
DIGITAL INPUT CHARACTERISTICS (GPIO[11:0])
VIH
Input HIGH Voltage
VIL
Input LO Voltage
0.7x VGPIO
Hysteresis
(4)
(5)
IIND
Digital Input Current
CIND
Input Capacitance
250
±0.005
mV
±1
4
µA
pF
Indicates the typical internal short circuit current limit. Sustained operation at this level will lead to device damage.
Device Specification is guaranteed by characterization and is not tested in production.
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Electrical Characteristics (continued)
Unless otherwise noted, these specifications apply for VDD=4.75V to 5.25V, REF=VDD, TA=25°C. Boldface limits are over
the temperature range of −30°C ≤ TA ≤ 85°C unless otherwise noted. DAC input code range 12 to 1012. DAC output
CL = 200 pF unless otherwise noted.
Symbol
Parameter
Conditions
Min
Typ
Max
Units
DIGITAL INPUT CHARACTERISTICS (CSB, DIN, SCLK)
VIH
Input HIGH Voltage
VIL
Input LO Voltage
0.7 x VIO
V
0.3 x VIO
Hysteresis
250
IIND
Digital Input Current
CIND
Input Capacitance
±0.005
V
mV
±1
4
µA
pF
DIGITAL OUTPUT CHARACTERISTICS (GPIO[11:0])
VOL
Output LO Voltage
VOH
Output HI Voltage
IOZH, IOZL
TRI-STATE Output Leakage
Current
COUT
Output Capacitance
IOUT = 200 µA
0.01
0.4
IOUT = 1.6 mA
VGPIO = VDD = 5V
0.07
0.4
IOUT = 200µA
VGPIO-0.2
IOUT = 1.6 mA
VGPIO = VDD = 5V
VGPIO-0.5
V
V
VGPIO=VDD
±5
4
µA
pF
DIGITAL OUTPUT CHARACTERISTICS (DOUT)
VOL
Output LO Voltage
VOH
Output HI Voltage
IOZH, IOZL
TRI-STATE Output Leakage
Current
COUT
Output Capacitance
IOUT = 200 µA
0.01
0.4
V
IOUT = 1.6 mA
VIO = 3.3V
0.07
0.6
V
IOUT = 200 µA
VIO-0.2
IOUT = 1.6 mA
VIO = 3.3V
VIO-0.5
V
VGPIO = 1.8V =VDD
±5
4
µA
pF
DIGITAL OUTPUT CHARACTERISTICS (DRDYB)
VOH_MAX
VOL
Maximum Output HI Voltage
Output LO Voltage
IOUT = 1.6 mA
VIO = 3.3V to VDD
VIO-0.5
Force 0V or VDD
µA
0.01
V
POWER SUPPLY CHARACTERISTICS
VDD
VGPIO
Supply Voltage Range
4.75
GPIO Rail Range
1.8
5
VDD
5.5
1.8
VDD
V
VIO
SPI Rail Range
IDD
Supply Current, Conversion Mode
OUT[3:0] pins RL = ∞
4
mA
PWRCONV
Power Consumption, Conversion
Mode
OUT[3:0] pins RL = ∞
21
mW
50
µA
2.7
V
IPD
VPOR
Supply Current, Power-Down
Mode
Power-On Reset
(6)
1.9
AC ELECTRICAL CHARACTERISTICS
tTRACK
ADC Track Time
Dictated by SPI bus activity
t8+9×t1
µs
tHOLD
ADC Hold Time
Dictated by SPI bus activity
15×t1
µs
ts
(6)
(7)
8
DAC Settling Time (7)
25%FS to 75%FS code change,
RL = 2K, CL = 200 pF
20
µs
During the power up the supply rail must ramp up beyond VPOR MIN for the device to acquire default state. After the supply rail has
reached the nominal level, the rail can drop as low as VPOR MAX for the current state to be maintained.
Device Specification is guaranteed by characterization and is not tested in production.
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Electrical Characteristics (continued)
Unless otherwise noted, these specifications apply for VDD=4.75V to 5.25V, REF=VDD, TA=25°C. Boldface limits are over
the temperature range of −30°C ≤ TA ≤ 85°C unless otherwise noted. DAC input code range 12 to 1012. DAC output
CL = 200 pF unless otherwise noted.
Symbol
tCONV
Parameter
Conditions
Min
Typ
Temperature Conversion Time
Max
Units
25.85
ms
SPI TIMING CHARACTERISTICS
t1
SPI Clock Period during ADC
data access
178
12500
ns
t1
SPI Clock Period during
Temperature Sensor access
178
5000
ns
t1
SPI Clock Period for all
transactions not involving ADC or
Temperature Sensor
100
tr
SCLK Rise Time
2
ns
tf
SCLK Fall Time
2
ns
t2
SCLK HIGH Time
8
ns
t3
SCLK LOW Time
8
ns
t4
CSB set-up time to SCLK falling
edge
5
ns
t5
DIN Set-up time
5
ns
t6
DIN Hold time
4
ns
t7
CSB hold time after 24th falling
edge of SCLK
10
ns
t8
CSB High Pulse Width
30
ns
tDH
DOUT hold time after SCLK
Rising Edge
tDD
DOUT Delay after SCLK Rising
Edge
t11
SCLK Delay after CSB Rising
Edge
CL=30pF, VIO=1.8
10
CL=30pF, 3V≤VIO≤5.25V
5
ns
ns
CL=30pF
40
3
tDOZ
CSB Rising Edge to DOUT TRISTATE
tZDO
CSB Falling Edge to DOUT active
ns
4
sink/source 200uA, CL=150pF
ns
5
10
ns
14
ns
SPI Interface Timing Diagram
| |
t1
70%
SCLK
1
70%
30%
2
t3
70%
tr
CSB
t8
DIN
DOUT
PD0
D23
D22
PD23
PD22
70%
23
24
tf
| | | | |
t2
70%
t11
D1
D0
PD1
PD0
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70%
SCLK
30%
CSB
30%
30%
t4
t7
70%
CSB
30%
SDO
tZDO
tDOZ
70%
SCLK
SDI
30%
70%
30%
t5
SCLK
SDO
10
70%
t6
70%
70%
30%
70%
30%
tDH
tDD
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Typical Performance Characteristics
ADC: INL
1.0
0.8
0.8
0.6
0.6
0.4
0.4
0.2
0.2
INL (lsb)
DNL (lsb)
ADC: DNL
1.0
0.0
-0.2
0.0
-0.2
-0.4
-0.4
-0.6
-0.6
-0.8
-0.8
-1.0
-1.0
0
256
512
768
OUTPUT CODE
1024
0
256
512
768
OUTPUT CODE
Figure 2.
Figure 3.
DAC: INL
1.0
1.0
0.8
0.8
0.6
0.6
0.4
0.4
0.2
0.2
INL (lsb)
DNL (lsb)
DAC: DNL
0.0
-0.2
0.0
-0.2
-0.4
-0.4
-0.6
-0.6
-0.8
-0.8
-1.0
-1.0
0 1002003004005006007008009001000
INPUT CODE
0
256
Figure 4.
0.4
1024
ADC: INL vs. Temperature
0.5
Min DNL
Max DNL
0.4
0.3
0.2
0.2
0.1
0.1
INL (lsb)
0.3
0.0
-0.1
-0.1
-0.2
-0.3
-0.3
-0.4
-0.4
-0.5
Min INL
Max INL
0.0
-0.2
-30
512
768
INPUT CODE
Figure 5.
ADC: DNL vs. Temperature
0.5
DNL (lsb)
1024
-0.5
-10
10
30
50
TEMPERATURE (°C)
70
90
Figure 6.
-30
-10
10
30
50
TEMPERATURE (°C)
70
90
Figure 7.
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Typical Performance Characteristics (continued)
DAC: DNL vs. Temperature
0.5
Min DNL
Max DNL
0.3
0.3
0.2
0.2
0.1
0.1
0.0
-0.1
0.0
-0.1
-0.2
-0.2
-0.3
-0.3
-0.4
-0.4
-0.5
-0.5
-30
-10
Min INL
Max INL
0.4
INL (lsb)
DNL (lsb)
0.4
DAC: INL vs. Temperature
0.5
10
30
50
TEMPERATURE (°C)
70
90
-30
-10
Figure 8.
70
90
Figure 9.
OUTx Output Load Regulation
Temperature Sensor Error
TEMPERATURE SENSOR ERROR (°C)
20
DEVIATION FROM MIDSCALE (mV)
10
30
50
TEMPERATURE (°C)
15
10
5
0
-5
-10
-15
-20
1.5
1.0
0.5
0.0
-0.5
-10 -8 -6 -4 -2 0 2 4 6 8 10
DAC OUTPUT CURRENT (mA)
-40 -20
Figure 10.
0 20 40 60 80 100 120
TEMPERATURE (°C)
Figure 11.
Internal Reference Output
Temperature Drift
REFERENCE ERROR (mV)
15
10
5
0
-5
-40 -20
0 20 40 60 80 100 120
TEMPERATURE (°C)
Figure 12.
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INSTRUCTION SET
The following is a complete listing of the instruction set supported by the LMP92018. Where applicable the
default state or register content is indicated in bold type.
The digital interface (SPI) protocol is described in SERIAL INTERFACE. The interface timing diagram is in SPI
Interface Timing Diagram
NOTE: the tables in following sections detail the data transfers of 2 subsequent SPI frames . The FRAME
1 column shows the user input into pin DIN of the device. The FRAME 2 column in the device output at
DOUT.
TEMPERATURE SENSOR CONFIGURE
A single bit, TSS, controls the mode of operation of the internal temperature sensor. The bit can be set and
tested via the SPI transactions shown in the following table. The internal temperature sensor is described in
DIGITAL TEMPERATURE SENSOR.
FRAME 1: DIN
Command
Bit→
FRAME 2: DOUT
Payload
Command
Payload
23
22:16
15:1
0
23
22:16
15:1
0
READ
1
0010000
x
x
1
0010000
000000000000000
TSS
WRITE
0
0010000
000000000000000
TSS
0
0010000
000000000000000
0
x
Don't Care
1: Temperature Sensor in Continuous Conversion Mode
TSS
0: Temperature Sensor In One Shot Mode
REFERENCE CONFIGURE
The internal reference mode of operation is controlled by a 3 bit sequence, CREF. The sequence can be set and
tested via the SPI transactions shown in the following table. The reference block is described in INTERNAL
VOLTAGE REFERENCE SOURCE.
FRAME 1: DIN
Command
Bit→
FRAME 2: DOUT
Payload
Command
Payload
23
22:16
15:3
2:0
23
22:16
15:3
2:0
READ
1
0010001
x
x
1
0010001
0000000000000
CREF
WRITE
0
0010001
0000000000000
CREF
0
0010001
0000000000000
000
x
Don't care
Reference Mode Selector
000: AREF external, DREF internal
001: AREF and DREF internal; REF pin is internally disconnected
010: AREF and DREF external
CREF
011: AREF internal, DREF external
100: Deep Sleep
101: AREF and DREF internal; REF driven by internal reference
110: Deep Sleep
111: Deep Sleep
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DAC CONFIGURE
The individual DACs can be enabled by setting a corresponding bit in the 4–bit CDAC word. The CDAC word can
be set and tested via the SPI transactions shown in the following table. The DAC block is described in
PROGRAMMABLE ANALOG OUTPUT SUBSYSTEM.
FRAME 1: DIN
Command
Bit→
FRAME 2: DOUT
Payload
Command
Payload
23
22:16
15:4
3:0
23
22:16
15:4
3:0
READ
1
0011000
x
x
1
0011000
000000000000
CDAC
WRITE
0
0011000
000000000000
CDAC
0
0011000
000000000000
0000
x
Don't care
1: enables DAC corresponding to bit position
CDAC
0: disables corresponding DAC
e.g. CDAC=[0101] enables DAC2 and DAC0
UPDATE ALL DACs
All 4 DAC channels' outputs can be simultaneously set to the same level corresponding to a 10–bit DDATA code.
The sequence in the following table provides a WRITE only functionality. The DAC block is described in
PROGRAMMABLE ANALOG OUTPUT SUBSYSTEM.
FRAME 1: DIN
Command
Bit→
FRAME 2: DOUT
Payload
Command
Payload
23
22:16
15:12
11:2
1:0
23
22:16
15:12
11:2
1:0
0
0011001
0000
DDATA
00
0
0011001
0000
0000000000
00
WRITE
x
Don't care
DDATA
DDATA will be loaded into all all DACs' input registers simultaneously. DDATA is a 10–bit unsigned integer.
GENERAL CONFIGURATION
The device can indicate to the new ADC conversion data availability via the DRDYB pin. This functionality is
enabled by setting the internal DRDY bit. The bit can be set and tested via the SPI transactions shown in the
following table. Details of the DRDYB pin functionality are described in Conversion Sequence and DIGITAL
TEMPERATURE SENSOR
FRAME 1: DIN
Command
Bit→
FRAME 2: DOUT
Payload
Command
Payload
23
22:16
15:1
0
23
22:16
15:1
0
READ
1
0011110
x
x
1
0011110
000000000000000
DRDY
WRITE
0
0011110
000000000000000
DRDY
0
0011110
000000000000000
0
x
Don't Care
DRDY
1: Disables the DRDYB pin function
0: Enables the DRDYB pin function
GPIO CONFIGURE
Individual bits of the general purpose digital I/O port can be configured to drive (output), or sense (input) only.
Setting a corresponding bit in the 12–bit CGPIO word will enable that pin to drive. The sequences in the following
table provide a READ and WRITE capability for the internal CGPIO register. The GPIO block is described in
GENERAL PURPOSE DIGITAL I/O.
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FRAME 1: DIN
Command
Bit→
FRAME 2: DOUT
Payload
Command
Payload
23
22:16
15:12
11:0
23
22:16
15:12
11:0
READ
1
0011111
x
x
1
0011111
0000
CGPIO
WRITE
0
0011111
0000
CGPIO
0
0011111
0000
000000000000
x
Don't Care
1: sets corresponding GPIO pin as output
CGPIO
0: sets corresponding GPIO pin as input
e.g. CGPIO=[000011110000] enables GPIO[7:4] pins as outputs, all other GPIO pins are inputs
STATUS
Internal bit, RDY, indicates when the device has completed its power-up sequence. The RDY bit can be tested
via the SPI transaction shown in the following table.
FRAME 1: DIN
Command
Bit→
FRAME 2: DOUT
Payload
Command
Payload
23
22:16
15:1
0
23
22:16
15:1
0
1
0100000
x
x
1
0100000
000000000000000
RDY
READ
x
Don't Care
Internal Power On Reset circuit sets this bit
RDY
1: device ready
0: device not ready
GPI STATE
The logic state present at the GPIO pins of the device is always reported in the SGPI register. The SGPI register
contents can be tested via the SPI transaction shown in the following table. The GPIO block is described in
GENERAL PURPOSE DIGITAL I/O.
FRAME 1: DIN
Command
Bit→
FRAME 2: DOUT
Payload
Command
Payload
23
22:16
15:12
11:0
23
22:16
15:12
11:0
1
0110000
x
x
1
0110000
0000
SGPI
READ
x
Don't Care
SGPI
Each bit Indicates the state at the corresponding GPIO pins of the device
GPO DATA
The GPIO pins configured to drive, will drive the state indicated in the CGPO register. The CGPO register can be
set or tested via the SPI transactions shown in the following table. The GPIO block is described in GENERAL
PURPOSE DIGITAL I/O.
FRAME 1: DIN
Command
Bit→
FRAME 2: DOUT
Payload
Command
Payload
23
22:16
15:12
11:0
23
22:16
15:12
11:0
READ
1
0110001
x
x
1
0110001
0000
CGPO
WRITE
0
0110001
0000
CGPO
0
0110001
0000
12'b0
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Don't Care
Each bit will be forced at the corresponding GPIO pin of the device. Bits corresponding to GPIO pins configured as inputs
will be ignored. CGPO[11:0]=0x000
CGPO
VENDOR ID
The 16–bit ID sequence is factory set, and can only be tested via the SPI transaction shown in the table below.
FRAME 1: DIN
Command
Bit→
READ
FRAME 2: DOUT
Payload
Command
Payload
23
22:16
15:0
23
22:16
15:0
1
1000000
x
1
1000000
ID
x
Don't Care
ID
Vendor ID number. ID = 0x0028.
VERSION/STEPPING
Version and Stepping words are factory set and can only be tested via the SPI transaction shown in the table
below.
FRAME 1: DIN
Command
Bit→
READ
FRAME 2: DOUT
Payload
Command
Payload
23
22:16
15:4
3:0
23
22:16
15:4
3:0
1
1000001
x
x
1
1000001
VER
STEP
x
Don't Care
VER
Indicates the device version number. VER=0x000
STEP
Indicates stepping number. STEP = 0x0
DAC DATA REGISTER ACCESS
Each DAC's input data register, DDATA, is individually addressable, and its contents can be updated without
affecting remaining 3 DACs. The content of each DDATA can be tested and set via the SPI transactions shown
in the following table. The DAC block is described in PROGRAMMABLE ANALOG OUTPUT SUBSYSTEM.
FRAME 1: DIN
Command
Bit→
FRAME 2: DOUT
Payload
Command
Payload
23
22:18
17:16
15:12
11:2
1:0
23
22:18
17:16
15:12
11:2
1:0
READ
1
10100
ADR
x
x
x
1
10100
ADR
0000
DDATA
00
WRITE
0
10100
ADR
0000
DDATA
00
0
10100
ADR
0000
10'b0
00
x
Don't Care
DAC address:
00: DAC0
ADR
01: DAC1
10: DAC2
11: DAC3
DDATA
16
DAC input data. DDATA is a 10–bit unsigned integer. DDATA=0x000
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ADC INPUT MUX SELECT DATA READ COMMAND
The selection of the analog input, and the read-back of the ADC conversion result are completed by the SPI
transaction shown in the following table. The ADC block is described in ANALOG SENSE SUBSYSTEM.
FRAME 1: DIN
Command
Bit→
READ
FRAME 2: DOUT
Payload
Command
Payload
23
22:19
18:16
15:12
11:2
1:0
23
22:19
18:16
15:12
11:2
1:0
1
1100
ADR
x
x
x
1
1100
ADR
0000
ADATA
00
x
Don't Care
ADC Input Address:
000: IN0
001: IN1
010: IN2
ADR
011: IN3
100: IN4
101: IN5
110: IN6
111: IN7
ADATA
ADC output Data. ADATA is a 10–bit unsigned integer.
TEMPERATURE SENSOR OUTPUT REGISTER
The contents of the internal temperature sensor output register can be tested by the SPI transaction shown in the
following table. The internal temperature sensor is described in DIGITAL TEMPERATURE SENSOR.
FRAME 1: DIN
Command
Bit→
READ
x
TDATA
FRAME 2: DOUT
Payload
Command
Payload
23
22:16
15:12
11:0
23
22:16
15:12
11:0
1
1110000
x
x
1
1110000
0000
TDATA
Don't Care
Temperature Sensor Output Data. TDATA is a 12–bit signed integer.
NOOP — No Operation
NOOP offers no functionality of its own. It is provided as the means of completing the pending READ operation
i.e. “pushing out” the data requested in the previous transaction.
FRAME 1: DIN
Bit→
NOOP
x
FRAME 2: DOUT
Command
Payload
Command
23:16
15:0
23:16
Payload
15:0
00000000
x
00000000
16'b0
Don't Care
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FUNCTIONAL DESCRIPTION
ANALOG SENSE SUBSYSTEM
The device is capable of monitoring up to 8 externally applied voltages. The system is centered around a 10-bit
SAR ADC fronted by an 8-input mux.
Sampling and Conversion
The external voltage is sampled onto the internal CHOLD capacitor during the TRACK period, see Figure 13. Once
acquired, the stored charge is measured using the Successive Approximation Register (SAR) method. The timing
of the internal state machine is governed by the user defined signals CSB and SCLK. The sequence of the
events is described in Conversion Sequence.
Attention should be paid to the output impedance of the sensed voltage source and the capacitance present at
the INx input of the device (which is dominated by CHOLD during TRACK time). The combined circuit's RC limits
the bandwidth and settling time of the input signal. At maximum SPI bus data rate, it is recommended to limit the
output resistance ROUT of the signal source to assure the accuracy of the conversion.
During the HOLD period (duration of t HOLD specified in Electrical Characteristics ) , all mux switches are OFF,
and the charge captured on CHOLD is measured to produce an ADC output code. This charge is never lost during
the conversion, unless the SCLK is so slow that the charge is lost due to the internal capacitor's leakage. Under
normal conditions the charge stored is modified only during TRACK period.
Below is a typical ADC output code as a function of input voltage at device pin INx, x=0...7:
ADATA = INT
V
x 1023)
(AREF
INX
(1)
In the expression above AREF is the reference voltage input to the internal ADC. See INTERNAL VOLTAGE
REFERENCE SOURCE.
Sampling
Switch
ROUT< 4k
INx
VDD/2
CHOLD
+
-
Voltage
Source
Device Pin
Figure 13. ADC During TRACK Period
Sampling Transient
As noted in Sampling and Conversion the charge acquired during TRACK period is maintained throughout the
conversion process. Since the successive sample operations will involve different input potentials an
instantaneous current will flow at the beginning of TRACK period. This always leads to temporary disturbance of
the input potential. This current, and resulting disturbance, will vary with the magnitude of the sampled signal and
source impedance ROUT, see Figure 13. If ROUT is excessive, and resulting RC time constant of the input
circuit too long, the preceding sample may affect the new sample's accuracy.
If high ROUT cannot be avoided, another method of improving the acquisitin accuracy is to lengthen the TRACK
time. The ADC TRACK time is fully controlled by the user inputs CSB and SCLK, see Figure 14. The time
allotted for the CHOLD to settle can be arbitrarily adjusted via the length of the CSB=High period and the
frequency of SCLK, subject to limitations on CSB and SCLK timing as shown in Electrical Characteristics .
18
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Conversion Sequence
The ADC conversion sequence and output activity are shown in Figure 14. The ADC readback occupies 2 SPI
frames. The first frame is used to issue a read command and connect the ADC input to the specified device input
pin INx. At the end of the first frame, at the rising edge of the CSB, the ADC sampling capacitor is connected to
the signal source, INx, and the TRACK period begins. The second frame executes the SAR algorithm (the HOLD
period) on the acquired sample and shifts the resulting data out through the DOUT output. The TRACK period
extends for 9 SCLK cycles, then the mux disconnects the sampling capacitor from the signal source, and the
SAR operation begins. The data is shifted out MSB first. Once the SAR operation is completed, the ADC powers
down for the remainder of the second frame.
If DRDYB output pin functionality is enabled, see GENERAL CONFIGURATION, then DRDYB output will be low
while ADC output data is present at DOUT.
If the ADC is not in TRACK or HOLD, the internal PD (Power Down) signal of the ADC is asserted thus powering
down all the active circuits of the ADC, and opening all analog input mux switches. See the PD period in the
Figure 14.
Frame 1
Frame 2
CSB
DIN
DOUT
READ IN0
dummy payload
COMMAND
PAYLOAD
Echo Previous
previous DATA IF ANY
READ IN0
ADATA
TRACK
HOLD
PD
CSB
1
9
12
SCLK
DRDYB
Figure 14. ADC Sequence Diagram
ADC Reference Selection
By default, the ADC operates from the external reference voltage applied at the REF pin of the device. It should
be noted that due to the architecture of the ADC the DC current flowing into the REF input is zero during
conversion. However, the transient currents ( see IVREF in Electrical Characteristics ) during the HOLD time can
be significant. For further details of reference source selection see INTERNAL VOLTAGE REFERENCE
SOURCE
Selection of the ADC reference source automatically dictates the attenuation level of the input signal. Figure 15
shows the ADC input configuration during the TRACK period when the REF pin is chosen as the source of the
reference voltage. The entire CHOLD available is used to acquire the signal. The transfer function of the ADC in
this configuration remains as shown in Sampling and Conversion
Sampling
Switch
15 pF
INx
VDD/2
15 pF
Device Pin
Figure 15. ADC Sampling when AREF is Externally Supplied
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In contrast, the Figure 16 shows the sampling capacitor during TRACK period when the internally generated
reference is selected as the reference source of the ADC. In this configuration ½CHOLD is used to sample the
input signal effectively attenuating it by a factor of 2. The resulting overall ADC transfer function becomes:
ADATA = INT
(2 xVAREF x 1023)
INX
(2)
15 pF
Sampling
Switch
INx
VDD/2
15 pF
Device Pin
Figure 16. ADC Sampling when AREF is Internally Supplied
PROGRAMMABLE ANALOG OUTPUT SUBSYSTEM
This subsystem consists of 4 identical DACs whose output is a function of the user programmable registers
DACx. This functionality is described in DAC Core. The DAC input registers are individually addressable, as
described DAC DATA REGISTER ACCESS. The user can also update all of the DAC input registers to the same
value with a single SPI command. See UPDATE ALL DACs
Each DAC channel can be individually enabled/disabled via the SPI interface command. See DAC CONFIGURE.
When a channel is disabled, its output OUTx is in HiZ state, but the DAC input register still maintains its data.
User can select the source of the reference input to all DACs. This functionality is described in DAC Reference
Selection
DAC Core
The DAC core is based on a Resistive String architecture which guarantees monotonicity of its transfer function.
The input data is single-registered, meaning that the OUTx of the DAC is updated as soon as the data is updated
in the DAC input data register at the end of the SPI transaction.
The functional diagram of the DAC Core is shown in Figure 17
VDD
DREF
0
1
R
R
R
DDATAx
DECODER
10
Buffer
OUTx
R
ä(R) = 200k
R
0
1
0
1
PD
Device Pin
Figure 17. DAC Block Diagram
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The ideal DAC core transfer function from DATAx to OUTx , x=0...3, can be expressed as:
DDATAx
OUTx = DREF
1024
)
(
(3)
The above expression is subject to non-idealities of the resistor string and limitations of the output buffer. These
limitations are tabulated in Electrical Characteristics
In Figure 17, the PD (Power Down) signal is asserted when the given channel is disabled via the SPI command.
The PD causes the DAC buffer bias currents to shut down, and it breaks the current path through the resistive
string.
DAC Reference Selection
All DAC channels operate from the same, user selectable, reference source. In Figure 17, DREF input can be
supplied by the external source, applied to the REF pin of the device, or from the internal reference generator
block. The reference block functionality is described in INTERNAL VOLTAGE REFERENCE SOURCE.
Reference selection automatically forces configuration of the DACs' output buffers. If the external reference
source, which is DREF driven by the REF device pin, is selected then all of the DAC output buffers are in 1x
configuration, as seen inFigure 18. In the external reference mode, each active DAC presents a resistive load to
the source attached to the device's REF pin, see Figure 17 and Figure 21.
The overall DAC transfers function remains as shown in DAC Core
+
-
600
Figure 18. DAC Buffer when DREF Externally Supplied
If the internal reference generator is selected to drive the DAC's DREF input, then all of the DACs' buffers are
automatically forced into 2x gain configuration as shown in Figure 19. This results in an overall transfer function
of the DACs to change to:
OUTx = 2 x DREF
(DDATAx
)
1024
(4)
+
-
100k
100k
Figure 19. DAC Buffer when DREF Internally Supplied
DIGITAL TEMPERATURE SENSOR
The local temperature sensor (TS) operates in one of the 2 possible modes: Continuous or One-Shot. The user
selects the mode of operation via the SPI instruction, see TEMPERATURE SENSOR CONFIGURE. The output
of the temperature sensor is a 12 bit signed integer, where each LSB represents 0.0625°C. Temperature
sensor's output code (TDATA) examples are shown in Table 1.
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Table 1. Temperature Readout Examples
Temperature
TDATA
125°C
0111.1101.0000
25°C
0001.1001.0000
0.0625°C
0000.0000.0001
0°C
0000.0000.0000
−0.0625°C
1111.1111.1111
−40°C
1101.1000.0000
In Continuous mode, the temperature sensor operates in the background and independently of the SPI bus
activity. Subsequent temperature conversion results are stored in the output register which can be accessed by
the user via the SPI interface.
In One-Shot mode temperature sensor is inactive until the user issues an instruction, via SPI interface, to read
the temperature sensor data. The temperature conversion commences at the rising edge of CSB following the
read instruction. After the delay of tCONV, the new temperature data is available in the temperature sensor output
register. If configured, the DRDYB output indicates when the temperature conversion has been completed, see
Figure 20.
The SPI instruction for accessing the temperature data is described in TEMPERATURE SENSOR OUTPUT
REGISTER
In Figure 20 below a One-Shot temperature read transaction is shown. The temperature readback occupies 2
SPI frames: the first frame is used to issue temperature sensor read instruction, the second frame is used for the
data readback. The falling edge of the DRDYB signal indicates the instance the new temperature data is present
in the output register. The DRDYB is deasserted by the rising edge of the CSB.
NOTE: The DRDYB output in One-Shot temperature conversion mode is asynchronous to the SCLK of
the SPI interface. DRDYB functionality is not provided in the Continuous mode of the temperature sensor
operation.
READ TS COMMAND
CSB
1
8
DIN
24
12
1
24
arb.
SCLK
arb.
arbitrary activity
arbitrary activity
DOUT
arb.
TDATA
DRDYB
tCONV
Figure 20. One-Shot Temperature Read Sequence
INTERNAL VOLTAGE REFERENCE SOURCE
The device has a built in precision 2.5V reference block which can be used to provide reference potential to
either the ADC (AREF) or the DACs (DREF), both at once, or to external load via REF pin. The precision
reference is always isolated from its loads by individual buffers, see Figure 21.
The CREF register sets the reference block mode of operation. The SPI instruction to update or read contents of
the CREF register is shown in REFERENCE CONFIGURE. The switch activity due to the CREF content is
tabulated in Table 2.
The modes corresponding to CREF=(100) or (110) or (111) are the Deep Sleep modes. In these modes the
internal temperature sensor, the ADC, the DACs, and the reference block buffers (but not the 2.5V reference) are
powered down.
22
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CREF
A
REF
B
C
D
Reference
AREF
E
DREF
SPI Control Word
Device Pin
Figure 21. Reference Selector Diagram
Table 2. Reference Selector Functionality
(1 to CLOSE Switch)
Switch
CREF
A
B
C
D
E
000
1
0
0
0
1
001
0
0
0
1
1
010
1
1
0
0
0
011
0
1
0
1
0
100
0
0
0
0
0
101
0
0
1
1
1
110
0
0
0
0
0
111
0
0
0
0
0
GENERAL PURPOSE DIGITAL I/O
The GPIO[11:0] port is memory mapped to registers SGPI and CGPO. Both registers are accessible through the
SPI interface.
The SGPI register content reflects at all times the digital state at the GPIOx device pins. The format of the read
command of the General Purpose Digital I/O is shown in GPI STATE.
The GPIOx pins can be configured as outputs by setting the individual bits in the CGPIO registers. Each bit in
CGPIO register enables corresponding output buffer in the GPIOx port. See GPIO CONFIGURE. Once the drive
is enabled, the logic state at the outputs is dictated by the contents of the CGPO register. See GPO DATA.
The functional diagram of the General Purpose Digital I/O is shown in Figure 22.
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SGPI[x]
GPIO[x]
CGPO[x]
EN
CGPIO[x]
SPI Control Word
Device Pin
Figure 22. General Purpose Digital I/O Diagram
SERIAL INTERFACE
The 4-wire interface is compatible with SPI, QSPI and MI- CROWIRE, as well as most DSPs. See the SPI
Interface Timing Diagram for timing information of the read and write sequences. The serial interface uses four
signals CSB, SCLK, DIN and DOUT.
A bus transaction is initiated by the falling edge of the CSB. Once CSB is low, the input data is sampled at the
DIN pin by the falling edge of the SCLK, and shifted into the internal shift register (FIFO). The output data is put
out on the DOUT pin on the rising edge of SCLK. At least 24 SCLK cycles are required for a valid transfer to
occur. If CSB is raised before 24th rising edge of the SCLK, the transfer is aborted and preceding data ignored. If
the CSB is held low after the 24th falling edge of the SCLK, the data will continue to flow through the internal
shift register (FIFO) and out the DOUT pin. When CSB transitions high, the internal controller decodes the FIFO
contents — most recent 24 bits that were received before the rising edge of CSB.
While CSB is high, DOUT is in a high-Z state. At the falling edge of CSB, DOUT presents the MSB of the data
present in the shift register. DOUT is updated on every subsequent falling edge of SCLK (note — the first DOUT
transition will happen on the first rising edge AFTER the first falling edge of SCLK when CSB is low).
The 24 bits of data contained in the FIFO are interpreted as an 8 bit COMMAND word followed by 16 bits of
DATA. The general format of the 24 bit data stream is shown in Figure 23. The full Instruction Set is tabulated in
Instruction Set.
COMMAND/PAYLOAD DECODE
CSB
DIN
COMMAND
8 bits
PAYLOAD
16 bits
Figure 23. General SPI Frame Format
SPI Write
SPI write operation occupies a single 24–bit frame, as shown in Figure 24. Write operation always starts with a
leading 0 (zero) in the 8–bit COMMAND sequence. The format of the data transfer and user instruction set is
shown in Instruction Set.
Note that write operation also produces DOUT activity. The DOUT output echoes back the previous frame's
COMMAND byte, followed by 16 zeros.
24
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Frame 1
Frame 2
CSB
DIN
DOUT
HiZ
WRITE COMMAND
8 bits
DATA
16 bits
Prior COMMAND
8 bits
PAYLOAD
16 bits
Next Command
8 bits
HiZ
WRITE COMMAND
8 bits
PAYLOAD
16 bits
All zero
16 bits
HiZ
Figure 24. SPI Write Transaction
SPI Read
The read operation requires all 4 wires of the SPI interface: SCLK, CSB, DIN, DOUT. The simplest read
operation occurs automatically during any valid transaction on the SPI bus since DOUT pin always shifts out the
leading 8 bits (COMMAND) of the previous transaction — this is regardless of the RW bit setting in the
COMMAND byte. This functionality gives the user an easy method of verifying the SPI link.
Reading of the specific content requires 2 SPI frames, as shown in Figure 25. The first frame is used to issue a
read command, which always begins with RW bit set in the COMMAND byte. The second frame echoes back the
first frame's COMMAND byte, followed by the 16–bit PAYLOAD containing the requested data. Consult
Instruction Set for the COMMAND format and returned data alignment within PAYLOAD.
Frame 1
Frame 2
CSB
DIN
DOUT
HiZ
READ COMMAND
8 bits
Arbitrary
16 bits
Prior COMMAND
8 bits
PAYLOAD
16 bits
HiZ
Next Command
8 bits
PAYLOAD
16 bits
READ COMMAND
8 bits
PAYLOAD
16 bits
HiZ
Figure 25. SPI Read Transaction
SPI Daisy Chain
It is possible to control multiple LMP92018s with a single master equipped with one SPI interface. This is
accomplished by connecting the multiple LMP92018 devices in a Daisy Chain. The scheme is depicted in
Figure 26. A chain of arbitrary length can be constructed since individual devices do not count the data bits
shifted in. Instead, they wait to decode the contents of their respective shift registers until CSB is raised high.
SYNC
CLK
(1)
(2)
(3)
SPI/QSPI
MICROWIRE
CSB
CSB
CSB
MASTER
SCLK
SCLK
SCLK
DIN DOUT
DIN DOUT
DIN DOUT
LMP92018
LMP92018
LMP92018
MOSI
MISO
Figure 26. SPI Daisy Chain
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A typical bus cycle for this scheme is initiated by the falling CSB. After the 24 SCLK cycles new data starts to
appear at the DOUT pin of the first device in the chain, and starts shifting into the second device. After the 72
SCLK cycles following the falling CSB edge, all three devices in this example will contain new data in their input
shift registers. Raising CSB will begin the process of decoding data in each device. When in the Daisy Chain the
full READ and WRITE capability of every device is maintained.
A sample of SPI data transfer appropriate for a 3 device Daisy Chain is shown in Figure 27.
72 Clock Cycles
CSB
MOSI
DATA (3)
DATA (2)
DATA (1)
Figure 27. SPI Daisy Chain Transaction
26
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SNAS514B – NOVEMBER 2011 – REVISED MAY 2013
Application Circuit Example
5V
0.01
10u
+ 0.1
499
VDD
REF
LM4050-4.1
10u
0.01 + 0.1
48V
222k
IN0
3.3V
3.3V
1n
10k
10k
5V
DRDYB
3.33k
IN1
Details of
Current
Sense
Omitted
LM8640
1n
12V
LMP92018
3.33k
LM8262
OUT1
uC
To Analog
Input
3.3V
10k
VIO
4.99k
CSB
SCLK
1.8V
DIN
DOUT
VGPIO
GPIO0
GPIO1
From Digital
Output
To Digital
Input
GND
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LMP92018
SNAS514B – NOVEMBER 2011 – REVISED MAY 2013
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REVISION HISTORY
Changes from Revision A (May 2013) to Revision B
•
28
Page
Changed layout of National Data Sheet to TI format .......................................................................................................... 27
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PACKAGE OPTION ADDENDUM
www.ti.com
3-May-2013
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
Lead/Ball Finish
(2)
MSL Peak Temp
Op Temp (°C)
Top-Side Markings
(3)
(4)
LMP92018SQ/NOPB
ACTIVE
WQFN
NJK
36
1000
Green (RoHS
& no Sb/Br)
CU SN
Level-3-260C-168 HR
-40 to 125
L92018SQ
LMP92018SQE/NOPB
ACTIVE
WQFN
NJK
36
250
Green (RoHS
& no Sb/Br)
CU SN
Level-3-260C-168 HR
-40 to 125
L92018SQ
LMP92018SQX/NOPB
ACTIVE
WQFN
NJK
36
2500
Green (RoHS
& no Sb/Br)
CU SN
Level-3-260C-168 HR
-40 to 125
L92018SQ
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4)
Multiple Top-Side Markings will be inside parentheses. Only one Top-Side Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a
continuation of the previous line and the two combined represent the entire Top-Side Marking for that device.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 1
Samples
PACKAGE MATERIALS INFORMATION
www.ti.com
14-Nov-2014
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
Package Package Pins
Type Drawing
LMP92018SQ/NOPB
WQFN
NJK
36
LMP92018SQE/NOPB
WQFN
NJK
LMP92018SQX/NOPB
WQFN
NJK
SPQ
Reel
Reel
A0
Diameter Width (mm)
(mm) W1 (mm)
B0
(mm)
K0
(mm)
P1
(mm)
W
Pin1
(mm) Quadrant
1000
330.0
16.4
6.3
6.3
1.5
12.0
16.0
Q2
36
250
178.0
16.4
6.3
6.3
1.5
12.0
16.0
Q2
36
2500
330.0
16.4
6.3
6.3
1.5
12.0
16.0
Q2
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
14-Nov-2014
*All dimensions are nominal
Device
Package Type
Package Drawing
Pins
SPQ
Length (mm)
Width (mm)
Height (mm)
LMP92018SQ/NOPB
WQFN
NJK
36
1000
367.0
367.0
38.0
LMP92018SQE/NOPB
WQFN
NJK
36
250
213.0
191.0
55.0
LMP92018SQX/NOPB
WQFN
NJK
36
2500
367.0
367.0
38.0
Pack Materials-Page 2
MECHANICAL DATA
NJK0036A
SQA36A (Rev A)
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