Battery Management Solutions (BMS)
The AD7284 contains all the functions required for the general-purpose monitoring of stacked Li-Ion batteries, as used in hybrid electric vehicles and battery backup applications.
The AD7284 has multiplexed cell voltage and auxiliary, analog-to-digital converter (ADC) measurement channels supporting four to eight cells of battery management. The device provides a maximum total unadjusted error, TUE, (cell voltage accuracy) of ±3 mV that includes all the internal errors from input to output. The primary ADC resolution is 14 bits.
The AD7284 also includes an integrated secondary measurement path that validates the data on the primary ADC. Other diagnostic features include the detection of open inputs, communication, and power supply related faults.
The AD7284 cell balancing interface outputs control the external field effect transistors (FETs) to allow discharging of individual cells.
There are two on-chip 2.5 V voltage references: one reference for the primary measurement path, and one for the secondary measurement path.
The AD7284 operates from one VDD supply, ranging from 10 V to 40 V. The device provides eight differential analog input channels to accommodate large common-mode signals across the full VDD range. Each channel allows an input signal range, VPINx − VPIN(x − 1) and VSINx – VSIN(x − 1), of 0 V to 5 V, where x = 0 to 8. The input pins assume a series stack of eight cells. The AD7284 includes four auxiliary ADC input channels that can be used for temperature measurement or system diagnostics.
The AD7284 has a differential daisy-chain interface that allows multiple devices to be stacked without the need for individual device isolation. By design, this interface allows both device to device communication within the same module and communication between devices on different modules.
- Li-Ion battery monitoring
- Electric and hybrid electric vehicles
- Stationary power applications
- Energy Storage
- Energy Monitoring
The ADuCM331 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 ADuCM331 has 128 kB program flash. and 4 kB data flash. The ADuCM331 is a complete system solution for battery monitoring in 12 V automotive applications. The ADuCM331 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 ADuCM331 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 ADuCM331 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 ADuCM331 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.
- Battery sensing/management for automotive and light mobility vehicles
- Lead-acid battery measurement for power supplies in industrial and medical domains
- Battery sensing/management for automotive systems