Overview
The BQ76925RGER, produced by Texas Instruments, is a host-controlled analog front end (AFE) designed for monitoring, balancing, and protecting 3- to 6-series cell lithium-ion (Li-Ion) and lithium-polymer batteries. This device is an integral part of a comprehensive battery management system, enabling a host controller to monitor individual cell voltages, pack current, and temperature with ease. It helps in detecting various unsafe or faulty operating conditions such as overvoltage, undervoltage, overtemperature, overcurrent, cell imbalance, state of charge, and state of health conditions.
Key Specifications
| Parameter | Description |
|---|---|
| Supply Voltage Range | 4.2 V to 26.4 V |
| Cell Input Range | 3- to 6-series cells |
| Current Sense Amplifier | Variable gain, capable of operation with 1-mΩ sense resistor |
| Reference Voltage | 1.5-/3.0-V low-drift, calibrated reference |
| Thermistor Bias Output | Switchable output for host temperature measurements |
| Overcurrent Comparator | Dynamically adjustable threshold, open-drain output |
| Cell Balancing FETs | Integrated, host-controlled, up to 50 mA balancing current |
| Communication Interface | I2C interface with optional packet CRC |
| Power Consumption | 40 µA typical in NORMAL mode, 1.5 µA maximum in SLEEP mode |
| Package Options | 20-pin TSSOP, 24-pin VQFN |
Key Features
- Analog interface for host cell measurement with cell input MUX, level shifter, and scaler.
- Analog interface for host current measurement with variable gain current sense amplifier.
- Switchable thermistor bias output for host temperature measurements.
- Overcurrent comparator with dynamically adjustable threshold.
- Integrated cell balancing FETs with host control up to 50 mA balancing current.
- Supports cell sense-line open wire detection.
- Integrated 3.3-V regulator for powering microcontroller or LEDs.
- I2C interface for host communications with optional packet CRC for robust operation.
- Low power consumption with 40 µA typical in NORMAL mode and 1.5 µA maximum in SLEEP mode.
Applications
- Primary Protection in Li-Ion Battery Packs
- Cordless power tools
- Light electric vehicles (e-Bike, scooter, etc.)
- UPS systems
- Medical Equipment
- Portable Test Equipment
Q & A
- What is the BQ76925RGER used for? The BQ76925RGER is used for monitoring, balancing, and protecting 3- to 6-series cell lithium-ion and lithium-polymer batteries.
- What is the supply voltage range of the BQ76925RGER? The supply voltage range is from 4.2 V to 26.4 V.
- How does the BQ76925RGER measure cell voltages? Cell input voltages are level-shifted, multiplexed, scaled, and output for measurement by a host ADC.
- What type of current sense amplifier does the BQ76925RGER have? It has a variable gain current sense amplifier capable of operation with a 1-mΩ sense resistor.
- How does the BQ76925RGER handle temperature measurements? It provides a separate output pin for biasing an external thermistor network, which can be switched on and off under host control.
- What is the function of the overcurrent comparator in the BQ76925RGER? The overcurrent comparator has a dynamically adjustable threshold and alerts the host through an open-drain output when the threshold is exceeded.
- How does the BQ76925RGER perform cell balancing? It integrates cell balancing FETs that are fully controlled by the host, with a balancing current set by external resistors up to 50 mA.
- What communication interface does the BQ76925RGER use? It uses an I2C interface with optional packet CRC for robust operation.
- What are the power consumption modes of the BQ76925RGER? It has a NORMAL mode with 40 µA typical power consumption and a SLEEP mode with 1.5 µA maximum power consumption.
- In what packages is the BQ76925RGER available? It is available in 20-pin TSSOP and 24-pin VQFN packages.
