Introduction To The Aducm362/Aducm363 - Analog Devices ADuCM362 Hardware Reference Manual

Hardware Reference Manual ADuCM362/ADuCM363

INTRODUCTION TO THE ADUCM362/ADUCM363

The ADuCM362 is a fully integrated, 4 kSPS, 24-bit data acquisition system incorporating dual, high performance, multichannel sigma-delta
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(Σ-Δ) analog-to-digital converters (ADCs), 32-bit ARM Cortex-M3 processor, and Flash/EE memory on a single chip. The device is 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 ADC0. ADuCM363 only has one ADC, ADC1.
The device contains an on-chip 32 kHz oscillator and an internal 16 MHz high frequency oscillator. This clock is routed through a programmable
clock divider from which the processor clock operating frequency is generated. The maximum clock speed is 16 MHz and is not limited by
operating voltage or temperature.
The microcontroller is a low power Cortex-M3 processor from ARM. It is a 32-bit RISC machine, offering up to 20 MIPS peak performance. The
Cortex-M3 processor incorporates a flexible 11-channel DMA controller supporting the following: 2 SPI, 2 UART, ADC and DAC. There are 256
kB of nonvolatile Flash/EE and 24 kB of SRAM integrated on chip.
The analog subsystem consists of dual ADCs, each connected to a flexible input multiplexer. 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 powering down of a bridge between conversions. The ADCs contain two parallel filters—a sinc3 or sinc4 in parallel with
a sinc2. The sinc3 or sinc4 filter is for precision measurements. The sinc2 filter is for fast measurements and for detection of step changes
in the input signal. The device also contains a low noise, low drift internal band gap reference or can be configured to accept up to two
external reference sources in ratiometric measurement configurations. An option to buffer the external reference inputs is also provided on
chip. A single-channel buffered voltage output DAC is also provided on chip. The ADuCM362/ADuCM363 also integrates a range of on-chip
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peripherals that can be configured under microcontroller software control as required in the application. These peripherals include UART, I C,
and dual SPI serial input/output (I/O) communication controllers, 19-pin GPIO ports, two general-purpose timers, wake-up timer, and system
watchdog timer. A 16-bit PWM with six output channels is also provided.
The ADuCM362/ADuCM363 is specifically designed to operate in battery-powered applications where low power operation is critical. The
microcontroller can be configured in a normal operating mode that consumes 290 μA/MHz (including flash/SRAM I ), resulting in an overall
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system current consumption of 1 mA when all peripherals are active.
The device can also be configured in a number of low power operating modes under direct program control, including hibernate mode (internal
wake-up timer active), which consumes only 4 µA. In hibernate mode, peripherals, such as external interrupts or the internal wake-up timer, can
wake up the device, thereby allowing the device to operate in an ultralow power operating mode 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 while nonintrusive
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emulation is also supported via the serial wire interface. These features are incorporated into a low cost QuickStart development system
supporting this precision analog microcontroller family.
The device operates from an external 1.8 V to 3.6 V voltage supply and is specified over an industrial temperature range of −40°C to +125°C.
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