Texas Instruments BQ7791501PWR

Overview

BQ7791501PWR from Texas Instruments is a stackable ultra-low power primary protector IC for 3- to 5-series Li-ion/Li-polymer battery packs, implementing autonomous voltage (±10 mV OV/±18 mV UV accuracy), current (OCD1: –10 to –85 mV; SCD: –40 to –340 mV), and temperature (OTD: 70°C; OTC: 50°C) protections with integrated 50-mA passive cell balancing. It enables e-bike and power tool pack safety without MCU supervision.

For engineers reviewing the BQ7791501PWR datasheet, BQ7791501PWR pinout, BQ7791501PWR application, or BQ7791501PWR equivalent, key selection criteria include its factory-programmed 4.25-V overvoltage threshold, 2.8-V undervoltage threshold, 20-ms OCD1 delay option, HIBERNATE mode (2 µA), and TSSOP-24 package compatibility with stacked multi-device architectures.

Technical Context

The BQ7791501PWR implements a fully autonomous protection architecture with independent CHG/DSG low-side NMOS FET drivers, resistor-programmable OCD delays via OCDP pin, and cascaded stack interface using LPWR/PRES pins. Its state comparator qualifies charge/discharge based on SRP–SRN differential voltage (±1.875 mV threshold).

Cell balancing is triggered by internal hysteresis logic (VHYST = 100 mV, VSTEP = 100 mV) between full-charge and overvoltage thresholds, with CBI/CBO pins enabling inter-device coordination in stacks. Temperature thresholds are derived from 10-kΩ NTC thermistor biasing at TS/VTB, yielding 70°C OTD and 50°C OTC setpoints.

Key Specifications

Pinout & Package

TSSOP-24 package (7.70 mm × 4.40 mm body size) with exposed thermal pad; 0.65-mm pitch; RoHS-compliant; rated for 36-V absolute maximum per cell input.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery protection applications.

Compared with BQ7791501PWR, BQ7791500PWR offers relaxed voltage thresholds and lower OTD, trading precision for broader margin; BQ7791502PWR provides faster OCD1 response but lacks the 4.25-V OV accuracy critical for high-density Li-ion cells.

Availability

BQ7791501PWR is available at Aetrix Electronics and suitable for power tools, e-bikes, and robotic vacuum cleaner designs requiring stable component supply, long-term lifecycle support, and automotive-grade reliability.

Supply support for BQ7791501PWR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management technologies with decades of battery management system expertise.

The BQ77915 family delivers autonomous, stackable protection for cost-sensitive, high-volume portable power applications - designed specifically for Li-ion/Li-polymer battery packs where MCU-free safety and ultra-low quiescent current are mandatory.

FAQ

What is the overvoltage protection threshold for BQ7791501PWR?

The BQ7791501PWR has a factory-programmed overvoltage threshold of 4.25 V ±10 mV, optimized for standard 4.2-V nominal Li-ion cells. This value is fixed and cannot be adjusted externally. The accuracy ensures reliable cell-level protection without risking overcharge-induced degradation, and it is verified across –40°C to +85°C operating temperatures per TI's SLUSCU0L datasheet.

Does BQ7791501PWR support stacking for more than 5-series battery configurations?

Yes, BQ7791501PWR supports stacking via its LPWR and PRES pins to scale beyond 5-series configurations. Up to four BQ7791501PWR devices can be cascaded to protect up to 20-series battery packs. Each upper device's LPWR connects to the PRES pin of the device below, enabling coordinated HIBERNATE entry/exit and cell balancing handoff - all without host controller intervention.

How does the cell balancing function work on BQ7791501PWR?

BQ7791501PWR executes autonomous passive cell balancing using integrated FETs capable of 50 mA per cell. Balancing activates when cell voltage exceeds VCBTH (programmed hysteresis above full-charge voltage), with VHYST = 100 mV and VSTEP = 100 mV defining the threshold window. The CBI/CBO pins coordinate balancing timing across stacked devices, and no external timing components are required for basic operation.

What is the quiescent current of BQ7791501PWR in HIBERNATE mode?

The BQ7791501PWR draws a maximum of 2 µA in HIBERNATE mode, as specified in the Electrical Characteristics table (IHIB parameter). This ultra-low current enables multi-year shelf life for battery packs in storage or shipping. The mode is activated by leaving the PRES pin floating, and exit requires a >1.5-V pulse held for >10 ms - a design feature explicitly validated for logistics and inventory management use cases.

Can BQ7791501PWR detect open-wire faults on cell connections?

Yes, BQ7791501PWR includes dedicated open-wire (OW) detection on all VCx pins with a 500-mV fault threshold and 100-mV hysteresis. When a cell connection opens, the voltage at the affected VCx pin falls below 450 mV relative to VCx−1, triggering a fault within 4.5 seconds. This protects against false undervoltage trips and ensures pack integrity verification before deployment - a requirement explicitly supported in TI's BQ7791501 device configuration.