BF8915A-1 BF8920A Energy Storage Chip Battery Management BF8915B-A

1.1 Chip Description

This product is a monitoring chip designed for collecting voltage and temperature data of high-voltage battery modules. The chip integrates a 16-bit incremental summation (Δ∑) ADC and a high-precision, low-temperature-drift voltage reference source. Under typical room temperature conditions, it achieves a battery measurement error of less than ±3mV. A single BF8915A-1 can monitor a 16-cell series battery module. By connecting multiple BF8915A-1 chips in series, simultaneous detection of up to hundreds of voltage and temperature channels can be achieved. Each BF8915A-1 chip features two serial differential communication ports. Multiple chips are connected via a daisy-chain communication link, enabling high-speed, high-noise-immunity local area communication. This daisy-chain communication supports bidirectional operation to ensure communication integrity. The chip supports both internal and external battery charge balancing control. The 16 internal balancing switches can support a maximum balancing current discharge of 200mA at 4.2V.

1.2 Overall Features

■

Operating temperature range: -40℃ to +125℃

■

Storage temperature range: -65℃ to +150℃

■

Voltage measurement error:

- ≤ ±3mV Accuracy (0V to 5V, +25°C)

- ≤ ±5mV Accuracy (0V to 5V, -20°C to +65°C)

- ≤ ±7mV Accuracy (0V to 5V, -40°C to +125°C)

- ≤ ±1mV Accuracy (0.5V to 4.5V, +25°C), after board-level calibration

■

A single chip can measure up to 16 series-connected lithium-ion battery voltages

■

Stackable architecture supports simultaneous detection of hundreds of battery cells and temperatures

■

Built-in serial differential communication interface:

- 1Mbps isolated serial communication

- Supports communication over twisted-pair cables longer than 10 meters

- Low EMI sensitivity and radiation

- Supports bidirectional communication for broken-wire protection

■

Completes all battery voltage detection within 4ms

■

On-chip channel synchronization time less than 4ms

■

Frequency-programmable 16-bit incremental summation (Δ∑) ADC dedicated to battery voltage and temperature detection

■

Programmable timer for battery charge balancing; balancing voltage threshold is configurable, enabling autonomous balancing after configuration

BF8915A-1

Datasheet

- 2 -

■ 16 internal balancing switches with asynchronous odd/even turn-on; balancing switch control duty cycle is configurable; maximum balancing current per channel is 200mA at 4.2V

■

Supports internal or external balancing

■

Built-in functional safety diagnostics

■ 8 general-purpose digital GPIO or analog inputs

- For temperature or other sensor inputs

■

Four configurable modes:

- SLEEP mode

- STANDBY mode

- MEASURE mode

- MONITOR mode

■

Insensitive to Latch-up effect

■ 64-pin eLQFP package

1.3 Application Scenarios

■ Electric vehicles and hybrid electric vehicles

■ Backup battery systems

■ Grid energy storage

■ High-power portable devices