BQ76952PFBR Basics
BQ76952PFBR is part of the BQ76952 series of battery monitoring and protection chips from Texas Instruments. It is a highly integrated, high-precision battery management solution. The device supports 3‑ to 16‑series Li-ion, Li-polymer, and LiFePO₄battery packs, integrating high-accuracy voltage, current, and temperature monitoring, along with configurable protection mechanisms, making it suitable for applications with strict safety and reliability requirements.
The BQ76952 series is widely used in battery monitoring and BMS designs, especially in drones, portable power supplies, high-capacity battery packs, electric scooters, and power tools, providing safe and precise cell monitoring and protection. In drone applications, the BQ76952PFBR serves as a core component of the battery management system (BMS), effectively ensuring stable operation of multi-series battery packs.
BQ76952PFBR Key Specs
Next, we will focus on the key specifications of the BQ76952PFBR. These specifications cover battery series support, monitoring accuracy, protection features, power consumption characteristics, package type, etc. They are important reference points when evaluating and selecting components.
Parameter | Value |
Model | BQ76952PFBR |
Manufacturer | Texas Instruments |
Part Status | Active |
Function | Multi-Function Controller |
Battery Chemistry | LiFePO4/Li-ion |
Number of Cells | 3 ~ 16 |
Fault Protection | Over Temperature |
Interface | I2C, SPI |
Operating Temperature | -40°C ~ 85°C (TA) |
Mounting Type | Surface Mount |
Package / Case | 48-TQFP |
Base Product Number |
BQ76952PFBR Features
• Battery monitoring capability for 3-series to 16- series cells
• Integrated charge pump for high-side NFET protection with optional autonomous recovery
• Extensive protection suite including voltage, temperature, current, and internal diagnostics
• Two independent ADCs
– Support for simultaneous current and voltage
sampling
– High-accuracy coulomb counter with input
offset error < 1 µV (typical)
– High accuracy cell voltage measurement < 10
mV (typical)
• Wide-range current applications (±200-mV measurement range across sense resistor)
• Integrated secondary chemical fuse drive protection
• Autonomous or host-controlled cell balancing
• Multiple power modes (typical battery pack operating range conditions)
– NORMAL mode: 286 µA
– Multiple SLEEP mode options: 24 µA to 41 µA
– Multiple DEEPSLEEP mode options: 9 µA to 10 µA
– SHUTDOWN mode: 1 µA
• High-voltage tolerance of 85 V on cell connect and select additional pins
• Tolerant of random cell attach sequence on production line
• Support for temperature sensing using internal sensor and up to nine external thermistors
• Integrated one-time-programmable (OTP) memory programmable by customers on production line
• Communication options include 400-kHz I2C, SPI, and HDQ one-wire interface
• Dual-programmable LDOs for external system usage
• 48-pin TQFP package (PFB)
Why Is BQ76952PFBR Suitable For Drone?
The BQ76952PFBR is very suitable for drones because it supports multiple battery series. Many industrial drones use 6S, 12S, or 14S batteries. The BQ76952PFBR can handle 3S to 16S packs, making it flexible for different drones.
It also has high-precision monitoring. The built-in ADC measures each cell’s voltage and current accurately. This helps drones estimate the state of charge (SoC) and flight time correctly.
The BQ76952PFBR also has high-side NFET control and strong protection features. The high-voltage charge pump can drive high-side N-channel MOSFETs directly. This keeps the system ground connected during protection events and prevents communication or sensor errors. It also provides over-voltage, under-voltage, over-current, and over-temperature protection, which helps drones work safely and extend battery life.
BQ76952PFBR in UAV Battery Management Systems
In modern drone (UAV) design, the battery management system is not just a safety feature. It is also key to improving flight efficiency. The BQ76952PFBR is highly integrated and has strong protection features. It has become a preferred solution for industrial and high-performance consumer drones.
1. High Series Support and Precise Monitoring
The BQ76952PFBR supports 3S to 16S Li-ion battery packs. This covers small survey drones (usually 4S–6S) to large agricultural or heavy-load logistics drones (usually 12S–14S). Its built-in high-accuracy ADC measures each cell’s voltage and current in real time with very low error. This precision ensures the flight controller gets accurate state-of-charge (SoC) data to calculate the return-to-home point precisely.
2. Safety Under Dynamic Loads
During takeoff, acceleration, or strong wind, drone currents can fluctuate sharply. The BQ76952PFBR has highly configurable over-current (OCD) and short-circuit (ASCD) thresholds. It can tell normal power pulses from dangerous current spikes. It also integrates a high-side N-channel MOSFET driver, so communication between the BMS and flight controller (like I²C or SPI) is not interrupted during protection events. This allows the flight controller to log errors or trigger emergency alerts.
3. Smart Battery and Flight Strategy Integration
With BQ76952PFBR, a regular Li-ion pack can become a smart battery. It works with an MCU to send battery cycle count, state-of-health (SoH), and real-time temperature to the flight platform via SMBus or CAN. In very cold or hot conditions, its multi-channel thermistor monitoring can trigger preheating or limit flight power. This reduces the risk of battery overheating and fire.
Key Considerations for UAV Design
Safety vs. Crash Risks
A major topic of discussion among drone engineers on the TI forums is the balance between protection logic and flight safety.
The Risk:
If the BQ76952 suddenly shuts off the MOSFETs due to an undervoltage or overcurrent trigger while the drone is in mid-air, the aircraft will lose power and crash instantly.
The Pro-Tip:
When designing your flight controller communication, it is often better to set the BQ76952 to a "monitor only" mode. Alternatively, let the flight controller make the final call on whether to cut power. In an emergency, it’s usually better to sacrifice the battery’s lifespan to save the entire drone.
Smart Battery Communication
The BQ76952 supports I2C, SPI, and HDQ protocols. This allows you to pull real-time battery data using a microcontroller (MCU) and pass it to the flight controller (like a Pixhawk or STM32) via CAN bus. This is the key to building a truly "Smart Battery" system.
Cell Balancing The chip supports both autonomous and host-controlled cell balancing. This is essential for keeping your battery cells in sync, which helps maintain consistent performance and extends the battery's life through many high-power flight cycles.
Cell Balancing
The chip supports both autonomous and host-controlled cell balancing. This is essential for keeping your battery cells in sync, which helps maintain consistent performance and extends the battery's life through many high-power flight cycles.
Ande Electronics: Offering Chip Solutions for UAVs
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These solutions help drone manufacturers accelerate product updates and technology deployment. They enable smart upgrades in mapping, inspection, logistics, and security, supporting more efficient and advanced UAV operations.
