Integrated, Precision Battery Sensor for Automotive Systems

The ADuCM330 is a fully integrated, 8 kSPS, data acquisition system that incorporates dual, high performance multichannel sigma-delta (Σ-Δ) ADCs, 32-bit ARM® Cortex™-M3 processor and flash. The ADuCM330 has 96 kB program flash and 4 kB data flash. The ADuCM330 is a complete system solution for battery monitoring in 12 V automotive applications. The ADuCM330 integrates all of the required features to precisely and intelligently monitor, process, and diagnose 12 V battery parameters including battery current, voltage, and temperature over a wide range of operating conditions.

Minimizing external system components, the device is powered directly from a 12 V battery. On-chip, low dropout (LDO) regulators generate the supply voltage for two integrated Σ-Δ ADCs. The ADCs precisely measure battery current, voltage, and temperature to characterize the state of the health and the charge of the car battery.

The device operates from an on-chip, 16.384 MHz high frequency oscillator that supplies the system clock. This clock is routed through a programmable clock divider from which the core clock operating frequency is generated. The device also contains a 32 kHz oscillator for low power operation.

The analog subsystem consists of an ADC with a programmable gain amplifier (PGA) that allows the monitoring of various current and voltage ranges. It also includes a precision reference on chip.

The ADuCM330 integrates a range of on-chip peripherals that can be configured under core software control as required in the application. These peripherals include a SPI serial input/output communication controller, six GPIO pins, one general-purpose timer, a wake-up timer, and a watchdog timer.

The ADuCM330 is specifically designed to operate in battery-powered applications where low power operation is critical. The microcontroller core can be configured in normal operating mode, resulting in an overall system current consumption of <18.5 mA when all peripherals are active. The device can also be configured in a number of low power operating modes under direct program control, consuming <100 µA. The ADuCM330 also includes a LIN physical interface for single wire, high voltage communications in automotive environments.

The device operates from an external 3.6 V to 18 V (on VDD, Pin 26) voltage supply and is specified over the −40°C to +115°C temperature range, with additional typical specifications at +125°C.

APPLICATIONS

* Battery sensing/management for automotive and light mobility vehicles

* Lead-acid battery measurement for power supplies in industrial and medical domains

* High precision analog-to-digital converters (ADCs)

* Dual channel, simultaneous sampling

* I-ADC 20-bit Σ-Δ (minimizes range switching)

* VADC/TADC 20-bit Σ-Δ

* Programmable ADC conversion rate from 1 Hz to 8 kHz

* On-chip ±5 ppm/°C voltage reference

* Current channel

* Fully differential, buffered input

* Programmable gain (from 4 to 512)

* ADC absolute input range: −200 mV to +300 mV

* Digital comparator with current accumulator feature

* Voltage channel

* Buffered, on-chip attenuator for 12 V battery input

* Temperature channel

* External and on-chip temperature sensor options

* Microcontroller

* ARM Cortex-M3 32-bit processor

* 16.384 MHz precision oscillator with 1% accuracy

* Serial wire download (SWD) port supporting code download and debug

* Automotive qualified integrated local interconnect network

* (LIN) transceiver