GENERAL DESCRIPTION
The ADuCM362-EP is a fully integrated, 3.906 kHz, 24-bit
data acquisition (DAQ) system that incorporates dual, high
performance, multichannel Σ-Δ analog-to-digital converters
(ADCs), a 32-bit ARM Cortex™-M3 processor, and Flash/EE
memory on a single chip. The ADuCM362-EP is designed for
direct interfacing to external precision sensors in both wired and
battery-powered applications.
The ADuCM362-EP contains 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
clock speed is not limited by operating voltage or temperature.
The microcontroller core is a low power ARM Cortex-M3
processor, 32-bit RISC machine that offers up to 20 MIPS peak
performance. The Cortex-M3 processor incorporates a flexible,
11-channel direct memory access (DMA) controller that supports
all wired communication peripherals (both serial peripheral
interfaces (SPIs), both universal asynchronous receivers/
transmitters (UARTs), and I2C). Also integrated on chip is
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
programmable gain amplifier (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
measurements and for the detection of step changes in the input signal.
The ADuCM362-EP contains a low noise, low drift internal
band gap reference, but the device 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 ADuCM362-EP integrates a range of on-chip peripherals
that can be configured under microcontroller software control
as required in the application. The peripherals include two
UARTs, an I2C, and dual SPI serial I/O communication
controllers, a 19-pin general-purpose input/output (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-EP is specifically designed to operate in batterypowered
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/SRAM IDD).
An overall system current consumption of 1 mA can be achieved
with both ADCs on (input buffers off), a PGA gain of 4, one
SPI port on, and all timers on.
The ADuCM362-EP 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.
Nonintrusive 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 microcontroller family.
The device operates from an external 1.8 V to 3.6 V voltage
supply and is specified over the −55°C to +125°C temperature range.
Additional application and technical information can be found
in the ADuCM362 data sheet.

FEATURES
Analog input/output: dual 24-bit ADCs
Programmable ADC conversion rate (3.5 Hz to 3.906 kHz)
Simultaneous 50 Hz/60 Hz noise rejection
At 50 Hz continuous conversion mode
At 16.67 Hz single conversion mode
Flexible input mux for input channel selection to both ADCs
Two 24-bit multichannel ADCs (ADC0 and ADC1)
6 differential or 12 single-ended input channels
4 internal channels for monitoring DAC, temperature
sensor, IOVDD/4, and AVDD/4 (ADC1 only)
Programmable gain (1 to 128)
Gain of 1 with input buffer on/off supported
RMS noise: 0.052 μV at 3.53 Hz and 0.2 μV at 50 Hz
Programmable sensor excitation current sources
On-chip precision voltage reference
Two external reference options supported by both ADCs
Single 12-bit voltage output DAC
NPN mode for 4 mA to 20 mA loop applications
Microcontroller
ARM Cortex-M3 32-bit processor
Serial wire download and debug
Internal watch crystal for wake-up timer
16 MHz oscillator frequency with 8-way programmable divider

APPLICATIONS
Weapons and munitions
Avionics
Unmanned systems
Intelligent precision sensing systems