Texas Instruments BQ7791504PW

Overview

BQ7791504PW 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: –20 mV to –170 mV), and temperature protections without MCU control. It features HIBERNATE mode (2 µA), integrated 50-mA passive cell balancing, and independent CHG/DSG FET drivers - deployed in e-bikes and robotic vacuum cleaners.

For engineers reviewing the BQ7791504PW datasheet, BQ7791504PW pinout, BQ7791504PW application, or BQ7791504PW equivalent, key selection criteria include its factory-programmed 4.275 V overvoltage threshold, disabled open-wire detection, and 3.5 V VSTART for reliable wake-up from storage mode - critical for high-reliability portable power systems.

Technical Context

The BQ7791504PW implements a fully autonomous protection architecture with no host communication required: all fault decisions are made internally using analog comparators and state machines. Its stackable interface uses LPWR/PRES signaling to cascade up to four devices for ≥6-series configurations, while CTRC/CTRD pins enable external override of CHG/DSG FETs.

Protection thresholds are factory-programmed and fixed per variant: BQ7791504PW has OV = 4.275 V, UV = 2.000 V, OTD = 65°C, OTC = 45°C, and disables both open-wire detection and current fault recovery - confirmed in Table 6-1 and Table 6-2 of the datasheet.

Key Specifications

Pinout & Package

TSSOP-24 package (7.70 mm × 4.40 mm nominal body size) with exposed thermal pad; rated for 36-V absolute maximum per cell input and –40°C to +85°C operating range.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ7791504PW, BQ7791502PW adds diagnostic capability at the cost of reduced UV headroom, while BQ7791506PW trades OV precision for broader chemistry support and recovery functionality - making BQ7791504PW optimal for cost-sensitive, fixed-threshold 3S–5S Li-ion applications where open-wire detection is unnecessary.

Availability

BQ7791504PW is available at Aetrix Electronics and suitable for e-bikes, robotic vacuum cleaners, and cordless power tools requiring stable component supply, long-term lifecycle assurance, and automotive-grade reliability in portable energy systems.

Supply support for BQ7791504PW 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 expertise in battery management solutions.

The BQ77915 family delivers autonomous, stackable primary protection for multi-cell Li-ion packs - designed specifically for cost-sensitive, high-volume portable power applications where MCU-free operation and ultra-low standby power are mandatory.

FAQ

What is the overvoltage protection threshold of the BQ7791504PW?

The BQ7791504PW has a factory-programmed overvoltage threshold of 4.275 V per cell with ±10 mV accuracy at 25°C. This value is fixed and cannot be adjusted externally - it is optimized for standard 4.2 V/cell Li-ion charging profiles and ensures precise cell-level cutoff without software calibration. The BQ7791504PW does not support user-programmable OV settings.

Does the BQ7791504PW support open-wire detection?

No, the BQ7791504PW explicitly disables open-wire detection (OW), as confirmed in Table 6-1 of the datasheet. Unlike variants such as BQ7791500 or BQ7791502, this part omits OW functionality to simplify design and reduce cost for applications where cell interconnect integrity is managed at the system level. The BQ7791504PW retains all other core protections including OV, UV, OCD, and temperature monitoring.

How does the HIBERNATE mode function on the BQ7791504PW?

HIBERNATE mode on the BQ7791504PW activates when the PRES pin is left floating, reducing quiescent current to 2 µA typical. Entry requires a 4.5-second deglitch period; exit occurs within 10 ms of applying a valid high signal to PRES. During HIBERNATE, all protections remain active, and the device wakes automatically at VSTART = 3.5 V - making the BQ7791504PW ideal for long-term storage of pre-charged battery packs.

Can the BQ7791504PW be used in stacks larger than 5-series?

Yes - the BQ7791504PW supports scalable stacking: up to four devices can be cascaded using LPWR/PRES and CBO/CBI pins to protect 6- to 20-series battery packs. Each device handles up to 5 cells, and inter-device communication maintains synchronized fault responses. For stacks beyond 20-series, timing skew must be evaluated per application; the BQ7791504PW itself remains unchanged in configuration.

What is the maximum cell-balancing current provided by the BQ7791504PW?

The BQ7791504PW delivers up to 50 mA of passive cell-balancing current through integrated FETs, sufficient for most 3–5S Li-ion applications. This eliminates external balancing transistors in standard designs. For higher currents, external FETs can be added using the CBI/CBO interface - but the BQ7791504PW's internal capability covers typical imbalance correction needs without added BOM cost.