Data Sheet

ADuCM360/ADuCM361

Rev. B | Page 3 of 24

GENERAL DESCRIPTION

The ADuCM360 is a fully integrated, 3.9 kSPS, 24-bit data

acquisition system that incorporates dual high performance,

multichannel sigma-delta (Σ-Δ) analog-to-digital converters

(ADCs), a 32-bit ARM Cortex™-M3 processor, and Flash/EE

memory on a single chip. The ADuCM360 is designed for

direct interfacing to external precision sensors in both wired

and battery-powered applications. The ADuCM361 contains

all the features of the ADuCM360 except that only one 24-bit

Σ-Δ ADC (ADC1) is available.

The ADuCM360/ADuCM361 contain an on-chip 32 kHz

oscillator and an internal 16 MHz high frequency oscillator. The

high frequency oscillator is routed through a programmable clock

divider from which the operating frequency of the processor core

clock is generated. The maximum core clock speed is 16 MHz;

this speed is not limited by operating voltage or temperature.

The microcontroller core is a low power ARM Cortex-M3

processor, a 32-bit RISC machine that offers up to 20 MIPS peak

performance. The Cortex-M3 processor incorporates a flexible,

11-channel DMA controller that supports all wired communica-

are 128 kB of nonvolatile Flash/EE memory and 8 kB of SRAM.

The analog subsystem consists of dual ADCs, each connected to

a flexible input mux. Both ADCs can operate in fully differential

and single-ended modes. Other on-chip ADC features include

dual programmable excitation current sources, diagnostic current

sources, and a bias voltage generator of AVDD_REG/2 (900 mV)

to set the common-mode voltage of an input channel. A low-side

internal ground switch is provided to allow power-down of an

external circuit (for example, a bridge circuit) between conversions.

The ADCs contain two parallel filters: a sinc3 or sinc4 filter in

parallel with a sinc2 filter. The sinc3 or sinc4 filter is used for

precision measurements. The sinc2 filter is used for fast measure-

ments and for the detection of step changes in the input signal.

The devices contain a low noise, low drift internal band gap ref-

erence, but they can be configured to accept one or two external

reference sources in ratiometric measurement configurations. An

option to buffer the external reference inputs is provided on chip.

A single-channel buffered voltage output DAC is also provided

on chip.

The ADuCM360/ADuCM361 integrate a range of on-chip

peripherals, which can be configured under microcontroller

software control as required in the application. The peripherals

controllers; a 19-pin GPIO port; two general-purpose timers;

a wake-up timer; and a system watchdog timer. A 16-bit PWM

controller with six output channels is also provided.

The ADuCM360/ADuCM361 are specifically designed to operate

in battery-powered applications where low power operation is

critical. The microcontroller core can be configured in a normal

operating mode that consumes 290 μA/MHz (including flash/

can be achieved with both ADCs on (input buffers off), PGA

gain of 4, one SPI port on, and all timers on.

The ADuCM360/ADuCM361 can be configured in a number

of low power operating modes under direct program control,

including a hibernate mode (internal wake-up timer active) that

consumes only 4 µA. In hibernate mode, peripherals such as

external interrupts or the internal wake-up timer can wake up the

device. This mode allows the part to operate with ultralow power

and still respond to asynchronous external or periodic events.

On-chip factory firmware supports in-circuit serial download

via a serial wire interface (2-pin JTAG system) and UART; non-

intrusive emulation is also supported via the serial wire interface.

These features are incorporated into a low cost QuickStart™

Development System that supports this precision analog micro-

controller family.

The parts operate from an external 1.8 V to 3.6 V voltage supply

and are specified over an industrial temperature range of −40°C

to +125°C.

More information on the ADuCM360/ADuCM361, see the

UG-367 user guide.