Texas Instruments BQ7790503PWR

Overview

BQ7790503PWR from Texas Instruments is a 3- to 5-series ultra-low-power lithium-ion battery protector IC implementing autonomous voltage, current, temperature, and open-wire protection without MCU intervention. It delivers ±10 mV overvoltage/undervoltage accuracy, 160 mV overcurrent discharge 2 threshold, 320 mV short-circuit discharge threshold, and supports stackable configurations up to 20-series cells for power tools and light electric vehicles.

For engineers reviewing the BQ7790503PWR datasheet, BQ7790503PWR pinout, BQ7790503PWR application, or BQ7790503PWR equivalent, key selection considerations include factory-programmed protection thresholds (OV = 4.20 V, UV = 2.70 V, OCD2 = 160 mV, SCD = 320 mV), independent CHG/DSG low-side NMOS drivers, 6 µA normal-mode current, and TSSOP-20 package compatibility with cascaded pack architectures.

Technical Context

The BQ7790503PWR operates as a standalone primary protector in lithium-ion battery packs, using internal comparators and fixed delay timers to autonomously trigger CHG/DSG FET shutdown upon fault detection. Its CCFG pin configures cell count (3–5 series), while CTRC/CTRD pins enable inter-device signal cascading for higher-series stacks.

Protection logic integrates dual overcurrent thresholds (OCD1 and OCD2), thermistor-based temperature sensing via TS/VTB pins, and open-wire detection across VC1–VC5 inputs. All thresholds and delays are factory-programmed-no external configuration or firmware is required.

Key Specifications

Pinout & Package

TSSOP-20 package (6.50 mm × 4.40 mm), RoHS-compliant, surface-mount, with exposed thermal pad (not electrically connected). Designed for automated assembly and thermal dissipation in compact battery modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ7790502PWR and BQ7790509PWR, the BQ7790503PWR provides balanced overvoltage margin (4.20 V) and robust short-circuit immunity (320 mV SCD threshold), making it optimal for power tools and e-vehicles where both high pulse tolerance and hard-fault safety are mandatory.

Availability

BQ7790503PWR is available at Aetrix Electronics and suitable for power tools, light electric vehicles, and energy storage systems requiring stable component supply, long-lifecycle support, and guaranteed traceability for ISO 13485 and IATF 16949 programs.

Supply support for BQ7790503PWR 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 ICs and functional safety design.

The BQ7790503PWR belongs to TI's BQ77905 family of stackable lithium-ion protectors, engineered for cost-sensitive, high-reliability battery packs in consumer, industrial, and transportation applications where MCU-free protection is essential.

FAQ

What protection functions does the BQ7790503PWR implement without microcontroller support?

The BQ7790503PWR implements autonomous overvoltage (4.20 V), undervoltage (2.70 V), overcurrent discharge 1 and 2, short-circuit discharge (320 mV), overtemperature/undertemperature charge and discharge, and open-wire detection-all using internal comparators and fixed delay timers. No firmware, external clock, or host processor is required for basic protection operation in the BQ7790503PWR.

How does the BQ7790503PWR support battery packs with more than five series cells?

The BQ7790503PWR supports >5-series configurations via daisy-chained stacking: the CHGU and DSG outputs of an upper device connect to the CTRC and CTRD inputs of the device below. This cascading architecture allows up to four BQ7790503PWR ICs to protect 20-series Li-ion packs while maintaining independent fault reporting and local FET control per segment.

What are the factory-programmed timing and threshold values specific to the BQ7790503PWR variant?

The BQ7790503PWR is configured with overvoltage threshold = 4.20 V (1-s delay), undervoltage threshold = 2.70 V (2-s delay), overcurrent discharge 2 threshold = 160 mV (350-ms delay), short-circuit discharge threshold = 320 mV (360-µs delay), overtemperature discharge = 70°C, and undertemperature charge = –5°C. These values are laser-trimmed and non-adjustable in-circuit.

Can the BQ7790503PWR be used in place of the BQ77904 series devices?

No-the BQ7790503PWR supports up to 5-series cell configurations and uses VC5 as an active sense input, whereas BQ77904 devices are limited to 4-series and require VC5 to be tied to VC4. The pinout is identical, but the internal logic and CCFG interpretation differ; substituting BQ7790503PWR into a BQ77904-designed board may cause incorrect cell-count detection or protection failure.

What is the role of the CCFG pin on the BQ7790503PWR, and how is it configured?

The CCFG pin on the BQ7790503PWR sets the number of series cells (3, 4, or 5) by voltage level relative to AVDD: ~10% = 3-cell, ~65–100% = 4-cell, ~25–45% (high-Z/floating) = 5-cell. Internal biasing detects the 5-cell state, enabling VC5 as a valid sense input-critical for correct operation of the BQ7790503PWR in 5-series battery packs.