Low-power AFE & ARM-core chip offers 16-bit measurement precision

August 14, 2014 // By Graham Prophet
Analog Devices has posted details of the AduCM350, which is a complete, coin cell powered, high precision, meter-on-chip for portable device applications such as point-of-care diagnostics and body-worn devices for monitoring vital signs. The ADuCM350 is designed for high precision potentiostat, current, voltage, and impedance measurement capabilities.

The device's analogue front end (AFE) features a 16-bit, precision, 160 ksamples/sec analogue-to-digital converter (ADC); 0.17% precision voltage reference; 12-bit, no missing codes digital-to-analogue converter (DAC); and a reconfigurable ultralow leakage switch matrix. It has four voltage measurement channels, up to 8 current measurement channels and an impedance measurement DFT engine. The ADuCM350 also includes an ARM Cortex-M3-based processor, memory, and all I/O connectivity to support portable meters with display, USB communication, and active sensors. It is packaged in a 120-lead, 8 × 8 mm CSP BGA and operates from −40°C to +85°C.

To support extremely low dynamic and hibernate power management, the ADuCM350 provides a collection of power modes and features, such as dynamic and software controlled clock gating and power gating. The AFE is connected to the ARM Cortex-M3 via an advanced high performance bus (AHPB) slave interface on the advanced microcontroller bus architecture (AMBA) matrix, as well as direct memory access (DMA) and interrupt connections.

The analogue feature set includes analogue hardware accelerators; an autonomous analogue front-end (AFE) controller, direct digital synthesiser (DDS)/arbitrary waveform generator, receive filters, plus the complex impedance measurement (DFT) engine. The 16 MHz Cortex M3 processor has 384 kB of embedded flash memory, 32 kB system SRAM and 16 kB Flash configured EEPROM. Communications comprise; I2S and beeper interface; LCD display controller (parallel and serial); LCD segment controller; SPI, I2C, and UART peripheral interfaces; plus programmable GPIOs. The part is coin-cell battery compatible; it has 2.0 V to 3.6 V hibernate operation, 2.5 V to 3.6 V active measurement range, a power management unit (PMU); power-on reset (POR) and power supply monitor (PSM).

ADI suggested uses include point-of-care diagnostics, body-worn devices for monitoring vital signs, and accurate measurement of currents, voltage or impedances.

Analog Devices; www.analog.com/en/processors-dsp/analog-microcontrollers/aducm350/products/product.html