Texas Instruments BQ7790511PWR

Overview

BQ7790511PWR from Texas Instruments is a 5-cell stackable lithium-ion battery protector IC implementing factory-programmed voltage, current, temperature, and open-wire protections without MCU control. It delivers ±10 mV overvoltage/undervoltage accuracy, 120 mV overcurrent discharge 2 threshold, and 65°C/45°C overtemperature/undertemperature discharge/charge thresholds - deployed in power tools and light electric vehicles requiring autonomous pack-level safety.

For engineers reviewing the BQ7790511PWR datasheet, BQ7790511PWR pinout, BQ7790511PWR application, or BQ7790511PWR equivalent, key selection criteria include its 5-series cell support, 90-ms OCD2 delay, load-removal recovery enablement, and TSSOP-20 package compatibility with cascaded multi-device stacks up to 20-series configurations.

Technical Context

The BQ7790511PWR operates in NORMAL mode at 6 µA quiescent current and SHUTDOWN mode at ≤0.5 µA, using independent low-side NMOS CHG and DSG FET drivers with programmable fault delays. Its protection logic relies on factory-configured thresholds - including 4250 mV OV, 2700 mV UV, and 120 mV OCD2 - with internal deglitching (7 ms on CTRC/CTRD) and thermistor-based temperature sensing via TS/VTB pins.

Cell count configuration is determined by CCFG pin voltage (5-cell mode when floating/internal bias), and stackability is enabled through CHGU-to-CTRC signal chaining between devices. All fault responses use internal delay timers, and open-wire detection employs 500 mV threshold with 100 mV hysteresis per cell sense input (VC1–VC5).

Key Specifications

Pinout & Package

Package: TSSOP-20 (PW), 6.50 mm × 4.40 mm body size, 0.65 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ7790511PWR, BQ7790512PWR offers higher UV tolerance and longer OCD2 delay for conservative overcurrent handling, while BQ7790502PWR provides colder UTC capability at the cost of slower fault reaction - both require no PCB changes but differ in thermal and timing behavior.

Availability

BQ7790511PWR is available at Aetrix Electronics and suitable for power tools, light electric vehicles, and start-stop battery packs requiring stable component supply, long-term lifecycle assurance, and automotive-grade reliability.

Supply support for BQ7790511PWR 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 BQ77905 family targets cost-sensitive, high-reliability lithium-ion battery packs needing autonomous, stackable protection - designed to replace microcontroller-based solutions in power tools, e-mobility, and energy storage.

FAQ

What is the configured overvoltage threshold for BQ7790511PWR?

The BQ7790511PWR has a factory-programmed overvoltage threshold of 4250 mV with ±10 mV accuracy at 25°C. This value is fixed and cannot be adjusted externally. The device uses this threshold to trigger overvoltage protection with a 1-second delay option, ensuring cell safety during charging without requiring calibration or external components. BQ7790511PWR implements this detection autonomously using its internal voltage comparators and reference circuitry.

Does BQ7790511PWR support 5-cell battery configurations natively?

Yes, BQ7790511PWR is specifically configured for 5-series lithium-ion battery stacks. It uses the CCFG pin's internal bias (floating state) to auto-detect 5-cell mode, eliminating external resistors. All five VC pins (VC1–VC5) are active and validated for simultaneous cell voltage monitoring, and the device's protection logic scales accordingly - unlike the BQ77904 which only supports up to 4 cells. BQ7790511PWR maintains full functionality across its specified –40°C to 85°C operating range in this configuration.

How does BQ7790511PWR handle overcurrent discharge events?

BQ7790511PWR implements two overcurrent discharge levels: OCD1 (–10 mV to –85 mV) and OCD2 (–20 mV to +170 mV). For BQ7790511PWR, OCD2 is set to 120 mV with a 90-ms delay - detecting moderate sustained overcurrents like motor stalls. Upon detection, it disables the DSG FET driver and holds the fault until recovery conditions (e.g., load removal or timeout) are met. BQ7790511PWR performs this entirely autonomously without MCU involvement.

What is the purpose of the LD pin on BQ7790511PWR?

The LD (Load Detection) pin on BQ7790511PWR monitors the PACK– node to detect physical disconnection of the load. When voltage at LD falls below 1.3 V, the device initiates load-removal recovery - automatically re-enabling the DSG FET after the load is reconnected. This feature eliminates manual reset requirements in applications like start-stop batteries. BQ7790511PWR uses an internal 250-kΩ pull-up and 1.3-V comparator to execute this function reliably across temperature.

Can BQ7790511PWR be used in stacked configurations beyond 5 cells?

Yes, BQ7790511PWR supports stacking up to 20-series cells using its CHGU and CTRC pins. In a stack, the upper device's CHGU output drives the lower device's CTRC pin to cascade charge control signals. Each BQ7790511PWR handles its local 5-cell segment, and the architecture requires no additional logic or communication bus. Up to four BQ7790511PWR devices can be daisy-chained, maintaining independent fault reporting and coordinated FET control - a core design feature of the BQ77905 family.