High Precision, Impedance, and
Electrochemical Front End
AD5940
Data Sheet
Fast power-up and power-down analog blocks for duty
FEATURES
Analog input
cycling
Programmable AFE sequencer to minimize workload of
host controller
6 kB SRAM to preprogram AFE sequences
Ultra low power potentiostat channel: 6.5 μA of current
consumption when powered on and all other blocks in
hibernate mode
16-bit, 800 kSPS ADC
Voltage, current, and impedance measurement capability
Internal and external current and voltage channels
Ultralow leakage switch matrix and input mux
Input buffers and programmable gain amplifier
Voltage DACs
Smart sensor synchronization and data collection
Cycle accurate control of sensor measurement
Sequencer controlled GPIOs
Dual output voltage DAC with an output range of 0.2 V
to 2.4 V
12-bit VBIAS0 output to bias potentiostat
6-bit VZERO0 output to bias TIA
On-chip peripherals
SPI serial input/output
Ultra low power: 1 μA
Wake-up timer
1 high speed, 12-bit DAC
Interrupt controller
Power
2.8 V to 3.6 V supply
Output range to sensor: 607 mV
Programmable gain amplifier on output with gain
settings of 2 and 0.05
1.82 V input/output compliant
Power-on reset
Amplifiers, accelerators, and references
1 low power, low noise potentiostat amplifier suitable for
potentiostat bias in electrochemical sensing
1 low noise, low power TIA, suitable for measuring sensor
current output
50 pA to 3 mA range
Programmable load and gain resistors for sensor output
Analog hardware accelerators
Hibernate mode with low power DAC and potentiostat
amplifier powered up to maintain sensor bias
Package and temperature range
3.6 mm × 4.2 mm, 56-ball WLCSP
Fully specified for operating temperature range of −40°C
to +85°C
Digital waveform generator
Receive filters
Complex impedance measurement (DFT) engine
1 high speed TIA to handle wide bandwidth input signals
from 0.015 Hz up to 200 kHz
APPLICATIONS
Electrochemical measurements
Electrochemical gas sensors
Potentiostat/amperometric/voltammetry/cyclic
voltammetry
Digital waveform generator for generation of sinusoid and
trapezoid waveforms
Bioimpedance applications
Skin impedance
2.5 V and 1.82 V internal reference voltage sources
System level power savings
Body impedance
Continuous glucose monitoring
Battery impedance
SIMPLIFIED BLOCK DIAGRAM
POTENTIOSTAT:
AMPLIFIER AND DAC
WAVEFORM
GENERATOR
ADC FIFO
AND MMR
CURRENT
CHANNELS
DFT
16-BIT
ADC
VOLTAGE
CHANNELS
DIGITAL
FILTERS
DATA FIFO
INTERNAL
CHANNELS
SLEEP/WAKEUP
TIMER
LDOs
SEQUENCER
TEMPERATURE
CHANNEL
INTERRUPTION
GENERATOR
VOLTAGE
REFERENCES
GPIOs
SPI
IMPEDANCE ENGINE
AMPLIFIERS AND DAC
Figure 1.
Rev. 0
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