Part: AD5940/AD5941

Type: High Precision, Impedance, and Electrochemical Front End

Description: High precision, impedance, and electrochemical front end with a 16-bit ADC offering 800 kSPS and 1.6 MSPS options, dual DACs, integrated potentiostat and TIA, and an SPI serial interface.

Operating Conditions:

• Supply voltage: 2.8 V to 3.6 V
• Operating temperature: -40°C to +85°C (AD5940/AD5941), -40°C to +105°C (AD5941W)
• ADC sample rates: 800 kSPS and 1.6 MSPS

Absolute Maximum Ratings:

• Not explicitly stated in the provided text.

Key Specs:

• ADC Resolution: 16-bit
• ADC Sample Rate: 800 kSPS / 1.6 MSPS options
• Low Power DAC Output Range: 0.2 V to 2.4 V
• High Speed DAC Output Range: ±607 mV
• Low Power TIA Current Range: 50 pA to 3 mA
• Ultra low power consumption: 1 μA
• High Speed TIA Bandwidth: 0.015 Hz up to 200 kHz
• Potentiostat Channel Current Consumption: 6.5 μA (powered on, other blocks in hibernate)

Features:

• 16-bit ADC with both 800 kSPS and 1.6 MSPS options
• Voltage, current, and impedance measurement capability
• Dual output voltage DAC with an output range of 0.2 V to 2.4 V
• Ultra low power: 1 μA
• 1 low power, low noise potentiostat amplifier
• 1 low noise, low power TIA, suitable for measuring sensor current output (50 pA to 3 mA range)
• Digital waveform generator for sinusoid and trapezoid waveforms
• Complex impedance measurement (DFT) engine
• SPI serial input/output
• Hibernate mode with low power DAC and potentiostat amplifier powered up to maintain sensor bias

Applications:

• Electrochemical measurements
• Electrochemical gas sensor measurements
• Potentiostat/amperometric/voltammetry/cyclic voltammetry
• Bioimpedance applications (Skin impedance, Body impedance, Continuous glucose monitoring)
• Battery impedance

Package:

• AD5940: 3.6 mm × 4.2 mm, 56-ball WLCSP
• AD5941: 7 mm × 7 mm, 48-lead LFCSP

• Analog input
• 16-bit ADC with both 800 kSPS and 1.6 MSPS options
• 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
• Dual output voltage DAC with an output range of 0.2 V to 2.4 V
• 12-bit V BIAS0 output to bias potentiostat
• 6-bit V ZERO0 output to bias TIA
• Ultra low power: 1 μA
• 1 high speed, 12-bit DAC
• Output range from high-speed DAC (HSDAC): ±607 mV
• Programmable gain amplifier on HSDAC output with gain settings of 2 and 0.05
• 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
• 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
• Digital waveform generator for generation of sinusoid and trapezoid waveforms
• 2.5 V and 1.82 V internal reference voltage sources
• System level power savings
• Fast power-up and power-down analog blocks for duty 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
• Smart sensor synchronization and data collection
• Cycle accurate control of sensor measurement
• Sequencer controlled GPIOs

• Electrochemical measurements
• Electrochemical gas sensor measurements
• Potentiostat/amperometric/voltammetry/cyclic voltammetry
• Bioimpedance applications
• Skin impedance
• Body impedance
• Continuous glucose monitoring
• Battery impedance

AD5940 56-Ball WLCSP Pinout

Notes

• Pin numbering follows the ball grid array (BGA) coordinate system: columns A–G (top to bottom), rows 1–8 (left to right).
• DNC (Do Not Connect) pins must not be connected to any signal.
• Analog and digital grounds (AGND, DGND) should be properly connected per layout guidelines.
• Multiple supply pins (AVDD, DVDD, KVDD) require appropriate decoupling capacitors.
• VREF_1V82 and VREF_2V5 are internal reference outputs; external load should be minimized.
• GPIO pins are configurable for various functions; see device configuration registers for detailed programming.

Stresses at or above those listed under Absolute Maximum Ratings may cause permanent damage to the product. This is a stress rating only; functional operation of the product at these or any other conditions above those indicated in the operational section of this specification is not implied. Operation beyond the maximum operating conditions for extended periods may affect product reliability.

Thermal performance is directly linked to printed circuit board (PCB) design and operating environment. Close attention to PCB thermal design is required.

θ JA is the natural convection junction to ambient thermal resistance measured in a one cubic foot sealed enclosure.

θ JC is the junction to case thermal resistance.