Data Sheet ADuCM362/ADuCM363
Rev. 0 | Page 3 of 24
GENERAL DESCRIPTION
The ADuCM362/ADuCM363 are fully integrated, 3.9 kSPS,
24-bit data acquisition systems that incorporate dual, high
performance, multichannel sigma-delta (Σ-) analog-to-digital
converters (ADCs), a 32-bit ARM Cortex™-M3 processor, and
Flash/EE memory on a single chip. The ADuCM362/
ADuCM363 are designed for direct interfacing to external
precision sensors in both wired and battery-powered applications.
The ADuCM363 contains all the features of the ADuCM362,
except that only one 24-bit Σ- ADC (ADC1) is available.
The ADuCM362/ADuCM363 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-
tion peripherals (both SPIs, both UARTs, and I
2
C). Also
integrated on chip are up to 256 kB of nonvolatile Flash/EE
memory and 24 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.
Optional input buffers are provided for the analog inputs and the
external reference inputs. These buffers can be enabled for all PGA
gain settings.
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
reference, but they can be configured to accept one or two
external reference sources in ratiometric measurement config-
urations. 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 ADuCM362/ADuCM363 integrate a range of on-chip
peripherals, which can be configured under microcontroller
software control as required in the application. The peripherals
include two UARTs, I
2
C, and dual SPI serial I/O communication
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 ADuCM362/ADuCM363 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 A/MHz (including flash/
SRAM I
DD
). An overall system current consumption of 1 mA can
be achieved with both ADCs on (input buffers off), PGA gain of
4, one SPI port on, and all timers on.
The ADuCM362/ADuCM363 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 devices. This mode allows the devices to operate with ultralow
power while still responding 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 devices 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.
