ADUCM355BCCZ

The ADuCM355 is an on-chip system that controls and measures electrochemical sensors and biosensors. It is an ultralow power, mixed-signal microcontroller based on the Arm Cortex-M3 processor. The device features current, voltage, and impedance measurement capability. The ADuCM355 features a 16-bit, 400 kSPS, multichannel successive approximation register (SAR) analog-to-digital converter (ADC) with input buffers, built-in antialias filter (AAF), and programmable gain amplifier (PGA). The current inputs include three transimpedance amplifiers (TIA) with programmable gain and load resistors for measuring different sensor types. The analog front end (AFE) also contains two low power amplifiers designed specifically for potentiostat capability to maintain a constant bias voltage to an external electrochemical sensor. The noninverting inputs of these two amplifiers are controlled by on-chip, dual output digital-to-analog converters (DACs). The analog outputs include a high speed DAC and output amplifier designed to generate an ac signal. The ADC operates at conversion rates up to 400 kSPS with an input range of -0.9 V to +0.9 V. An input mux before the ADC allows the user to select an input channel for measurement. These input channels include three external current inputs, multiple external voltage inputs, and internal channels. The internal channels allow diagnostic measurements of the internal supply voltages, die temperature, and reference voltages. Two of the three voltage DACs are dual output, 12-bit string DACs. One output per DAC controls the noninverting input of a potentiostat amplifier, and the other controls the noninverting input of the TIA. The third DAC (sometimes referred to as the high speed DAC) is designed for the high power TIA for impedance measurements. The output frequency range of this DAC is up to 200 kHz. A precision 1.82 V and 2.5 V on-chip reference source is available. The internal ADC and voltage DAC circuits us

Applications

• Gas detection
• Food quality
• Environmental sensing (air, water, and soil)
• Blood glucose meters
• Life sciences and biosensing analysis
• Bioimpedance measurements
• General amperometry, voltammetry, and impedance spectroscopy functions

Key features

• Analog input/output 16-bit, 400 kSPS ADC
• Voltage, current, and impedance measurement capability
• Internal and external current and voltage channels
• Ultralow leakage switch matrix and input mux
• Input buffers, PGA
• Voltage DACs: Two dual output voltage DACs, Output range: 0.2 V to 2.4 V [±2.2 V voltage potential to sensor) for 12-bit outputs
• Two bias potentiostat and TIA amplifiers, Ultralow power, μA per amplifier
• One high speed 12-bit voltage DAC, Output range to sensor: -607 mV to +607 mV
• High speed TIA for impedance measurements
• Programmable gain amplifier on output
• Amplifiers, accelerators, and references: Two low power, low noise amplifiers, Suitable for potentiostat bias in electrochemical sensing
• Two low power, low noise TIAs, Suitable for measuring sensor current output in the ±0.00005 μA to ±3000 μA range
• Programmable load and gain resistors
• Analog hardware accelerators
• Digital waveform generator
• DFT and digital filters
• 2.5 V and 1.82 V on-chip, precision voltage references
• Internal temperature sensor, ±2℃ accurate
• Impedance measurement range of <1 Ω to 10 MΩ, 0.016 Hz to 200,000 Hz
• Voltammetry scan rate up to 2000 steps per second
• Microcontroller: 26 MHz Arm Cortex-M3 processor
• Serial wire port supports code download and debugging
• 128 kB flash/64 kB of SRAM
• Security and safety: Hardware cyclic redundancy check (CRC) with programmable polynomial generator
• Read and write protection of user flash
• On-chip peripherals: UART, I2C, and SPI serial input/output
• Up to 17 GPIO pins
• External interrupt option
• General-purpose, wake-up, and watchdog timers
• Power: 2.8 V to 3.6 V supply and active measurement range
• Power supply monitor
• Active current consumption: 30 μA/MHz for digital section
• Hibernate with bias to external sensor: 8.5 μA
• Shutdown mode with no SRAM retention: 2 μA
• Package and temperature range: 6 mm×5 mm, 72-lead LGA package
• Fully specified for -40℃ to +85℃ ambient operation