ADI ADUCM355BCCZ-RL7

ADuCM355 is a system-on-chip for controlling and measuring electrochemical and biosensors. It is an ultra-low power mixed-signal microcontroller based on the Arm Cortex-M3 processor. The device has current, voltage, and impedance measurement capabilities.

ADuCM355 incorporates a 16-bit, 400 kSPS multi-channel successive approximation register (SAR) analog-to-digital converter (ADC) with an input buffer, anti-aliasing filter (AAF), and programmable gain amplifier (PGA). The current inputs include three transimpedance amplifiers (TIAs) with programmable gain and load resistors for measuring different sensor types. The analog front end (AFE) also contains two low-power amplifiers specifically designed for potentiostat capabilities to maintain a constant bias voltage for external electrochemical sensors. The non-inverting inputs of these two amplifiers are controlled by an on-chip dual-channel output digital-to-analog converter (DAC). The analog outputs include a high-speed DAC and an output amplifier for generating AC signals.

The ADC has a conversion rate of up to 400 kSPS and an input range of -0.9 V to +0.9 V. The input multiplexer in front of the ADC allows the user to select input channels for measurement. These input channels include three external current inputs, multiple external voltage inputs, and internal channels. Using the internal channels, diagnostic measurements can be made of the internal supply voltage, chip temperature, and reference voltage source.

Two of the three voltage DACs are dual-channel output, 12-bit resistor string DACs. One output of each DAC can control the non-inverting input of the potentiostat amplifier, and the other controls the non-inverting input of the TIA.

The third DAC (sometimes referred to as the high-speed DAC) is designed for a high-power TIA used in impedance measurement. The output frequency range of this DAC is up to 200 kHz.

Precision 1.82 V and 2.5 V on-chip reference voltage sources are provided. The internal ADC and voltage DAC circuits use this on-chip reference voltage source to ensure low drift performance of all peripherals.

ADuCM355 integrates a 26 MHz Arm Cortex-M3 processor, which is a 32-bit reduced instruction set computer (RISC). The ARM Cortex-M3 processor also has a flexible multi-channel direct memory access controller (DMA) that supports two independent serial peripheral interface (SPI) ports, a universal asynchronous receiver/transmitter (UART), and I²C communication peripherals. ADuCM355 also integrates 128 kB of non-volatile flash/EE memory and 64 kB of static random access memory (SRAM) on-chip.

The digital processor subsystem receives a clock signal from a 26 MHz on-chip oscillator. This oscillator is the main digital chip system clock source. Alternatively, a 26 MHz phase-locked loop (PLL) can be used as the digital system clock. This clock is divided internally so that the processor can operate at a lower frequency and save power. The device also incorporates a low-power 32 kHz oscillator that can clock the timers. ADuCM355 includes 3 general-purpose timers, 1 wake-up timer (which can be used as a general-purpose timer), and 1 system watchdog timer.

The analog subsystem incorporates a separate 16 MHz oscillator to provide a clock source for the ADC, DAC, and other digital logic elements on the analog chip. The analog chip also contains a separate 32 kHz, low-power oscillator to provide a clock source for the watchdog timer on the analog chip. The 32 kHz oscillator and this watchdog are independent of the digital chip oscillator and system watchdog timer.

Multiple communication peripherals can be configured according to specific application requirements. These peripherals include a UART, I²C, two SPI ports, and general-purpose input/output (GPIO) ports. The GPIO, combined with the general-purpose timers, can be combined to generate pulse width modulation (PWM)-like outputs.

The device supports non-intrusive emulation and programming download through a serial wire debug port (SW-DP) interface.

ADuCM355 is powered by a 2.8 V to 3.6 V power supply and is rated for a temperature range of -40℃ to +85℃. The chip is available in a 72-pin 6 mm x 5 mm land grid array (LGA) package.

• 16-bit, 400 kSPS ADC for voltage, current, and impedance measurement
• Internal and external current and voltage channels
• Ultra-low leakage switch matrix and input multiplexer
• Input buffer, PGA
• 2 dual-output voltage DACs
• Output range: 0.2 V to 2.4 V (±2.28 sensor potential difference) for 12-bit output
• 2 bias potentiostats and TIA amplifiers
• Ultra-low power consumption, <1 μA per amplifier
• 1 high-speed 12-bit voltage DAC
• Sensor output range: -607 mV to +607 mV
• Programmable gain amplifier on high-speed TIA output for impedance measurement
• 2 low-power, low-noise amplifiers suitable for potentiostat bias in electrochemical detection
• 2 low-power, low-noise TIAs suitable for measuring sensor currents in the range of ±0.00005 μA to ±3000 μA
• Programmable load and gain resistors on output
• Analog hardware accelerator
• Digital waveform generator
• DFT and digital filters
• 2.5 V and 1.82 V on-chip precision reference voltage sources
• Internal temperature sensor, ±2℃ accuracy
• Impedance measurement range: <1 Ω to 10 MΩ, 0.016 Hz to 200,000 Hz
• Voltammetric scan rate up to 2000 steps per second
• 26 MHz Arm Cortex-M3 processor
• Serial wire port supports code download and debugging
• 128 kB flash/64 kB SRAM

• Gas detection
• Food quality
• Environmental detection (air, water, and soil)
• Blood glucose meters
• Life science and biosensing analysis
• Bioimpedance measurement
• General amperometric detection, voltammetry, and impedance spectroscopy analysis