Texas Instruments BQ7791504PWR

Overview

BQ7791504PWR 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 integrates independent CHG/DSG low-side NMOS drivers and supports smart passive cell balancing up to 50 mA per cell - used in e-bikes, power tools, and robotic vacuum cleaners.

For engineers reviewing the BQ7791504PWR datasheet, BQ7791504PWR pinout, BQ7791504PWR application, or BQ7791504PWR equivalent, this page delivers verified technical context, exact pin functions, confirmed protection thresholds, HIBERNATE mode behavior, and validated alternative options for 3–5S pack designs requiring autonomous, ultra-low-quiescent (2 µA) protection.

Technical Context

The BQ7791504PWR implements a fixed-function analog protection architecture with factory-programmed thresholds: overvoltage set to 4.275 V (±10 mV), undervoltage to 2.0 V (±18 mV), and OCD1 threshold at –20 mV with 1-s delay. It uses dedicated SRP/SRN differential current sensing and dual thermistor inputs (TS/VTB) for independent OTD/OTC/UTD/UTC detection - with no software or host interface required.

Its stackable interface enables multi-device cascading via LPWR→PRES and CBO→CBI links, supporting scalable configurations beyond 5S. The device operates in three distinct modes: NORMAL (8 µA), HIBERNATE (2 µA), and SHUTDOWN (0.5 µA), with PRES pin-controlled entry/exit and deglitch timing of 4.5 s (entry) and 10 ms (exit).

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ7791504PWR, BQ7791502PWR adds UV fault recovery capability but shares identical HIBERNATE current and balancing architecture, while BQ7791506PWR targets LFP cells with reduced OV/UV thresholds and built-in recovery timing - neither is pin-compatible nor functionally interchangeable without layout and threshold revalidation.

Availability

BQ7791504PWR is available at Aetrix Electronics and suitable for e-bike battery management, power tool pack protection, and robotic vacuum cleaner safety systems requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for BQ7791504PWR 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 and embedded processing technologies, with decades of expertise in battery management system (BMS) IC design and functional safety validation.

The BQ77915 family was engineered for cost-sensitive, high-volume portable Li-ion applications requiring zero-host supervision - delivering autonomous protection, ultra-low-power HIBERNATE, and scalable stacking in compact TSSOP packages.

FAQ

What is the overvoltage protection threshold for BQ7791504PWR?

The BQ7791504PWR has a factory-programmed overvoltage threshold of 4.275 V ±10 mV per cell, as confirmed in Table 6-1 of the datasheet. This value is fixed and not user-adjustable. The BQ7791504PWR uses this precise threshold to prevent Li-ion cell overcharge, ensuring compliance with JEITA guidelines. No external components modify this setting - it is laser-trimmed during manufacturing.

Does BQ7791504PWR support cell balancing, and how is it implemented?

Yes, BQ7791504PWR supports smart passive cell balancing using integrated FETs capable of up to 50 mA per cell. Balancing is triggered when cell voltage exceeds VCBTH (programmable hysteresis range: 50–200 mV above VOV). The BQ7791504PWR coordinates balancing across stacked devices via CBI/CBO pins, and external FETs can be added for higher current. No MCU or external timing circuit is required.

How does HIBERNATE mode operate on BQ7791504PWR?

HIBERNATE mode on BQ7791504PWR reduces quiescent current to 2 µA by disabling internal comparators and drivers. Entry requires PRES pin left floating for ≥4.5 s (deglitched), and exit occurs when PRES is driven high (>1.5 V) for ≥10 ms. During HIBERNATE, all protections remain inactive - it is intended only for shipping/storage, not operational use. The BQ7791504PWR resumes NORMAL mode automatically upon wake-up.

Is BQ7791504PWR pin-compatible with other BQ77915 variants?

No, BQ7791504PWR is not pin-compatible with other BQ77915 variants in terms of protection behavior - though physical pinout and package are identical across the family. Its OCDP pin is disabled (no OCD delay programming), open-wire recovery is disabled, and temperature thresholds differ. Functional compatibility requires verification of OV/UV/OCD values, recovery logic, and balancing enablement - all specific to BQ7791504PWR's configuration.

What is the maximum supported cell count for BQ7791504PWR in a stacked configuration?

The BQ7791504PWR supports up to 20-series cells when four devices are stacked using LPWR→PRES and CBO→CBI interconnects. Each BQ7791504PWR handles up to 5 cells directly; stacking extends coverage linearly. The datasheet confirms scalability "to 20 series or more", and timing analysis shows cumulative delay remains within specification up to 20S. Beyond 20S, system-level validation of fault propagation delay is required for BQ7791504PWR deployments.