Texas Instruments BQ7720500DGKR

Overview

BQ7720500DGKR from Texas Instruments is a dedicated overvoltage protection IC for 3- to 5-series Li-ion battery packs, featuring ±10 mV overvoltage detection accuracy at 25°C, fixed 4.2 V OVP threshold, 1 s internal delay timer, and active-low open-drain output drive. It operates across –40°C to 85°C ambient temperature and supports handheld power tools requiring precise, latch-free cell-level fault response.

For engineers reviewing the BQ7720500DGKR datasheet, BQ7720500DGKR pinout, BQ7720500DGKR application, or BQ7720500DGKR equivalent, key selection criteria include its fixed 4.2 V OVP setpoint, 1-second fault delay, DGK-8 VSSOP package compatibility, and integration-ready open-wire detection without external timing components.

Technical Context

The BQ7720500DGKR implements independent per-cell voltage monitoring with comparator-based overvoltage detection referenced to a trimmed internal bandgap. Its fixed 1-second delay timer initiates upon any cell exceeding 4.2 V and triggers the active-low OUT pin only after timeout-no latching, no external RC timing network required.

Open-wire detection uses periodic 50-μA pulldown current on each V_n input (n = 1–5), comparing V_n against V_n−1 − 200 mV to identify broken connections. The OUT pin functions as an open-drain output capable of sinking ≥0.3 mA when active, compatible with external pull-up to VDD or system logic rails.

Key Specifications

Pinout & Package

Package: 8-pin VSSOP (DGK), 5.0 mm × 3.0 mm body, 0.65 mm lead pitch, RoHS-compliant, moisture sensitivity level 2 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ7720500DGKR, BQ7720501DGKR offers higher OVP precision for advanced Li-ion variants but extends fault response time to 2 seconds; BD49E42G reduces cost and footprint for 1S designs but cannot replace BQ7720500DGKR in multi-cell stacks due to missing V2–V5 inputs and open-wire functionality.

Availability

BQ7720500DGKR is available at Aetrix Electronics and suitable for handheld power tools, cordless vacuum cleaners, and light electric vehicle battery packs requiring stable component supply, long-lifecycle support, and automotive-grade reliability validation.

Supply support for BQ7720500DGKR 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and personal electronics markets.

The BQ77205 product line delivers integrated, pin-configured overvoltage and open-wire protection for multi-cell Li-ion battery packs-designed specifically for cost-sensitive, high-volume portable power applications where firmware-free protection is mandatory.

FAQ

What is the exact overvoltage protection threshold of the BQ7720500DGKR?

The BQ7720500DGKR has a factory-trimmed, fixed overvoltage protection threshold of 4.2 V with ±10 mV accuracy at 25°C. This value is permanently programmed into the device and cannot be adjusted externally. The BQ7720500DGKR does not support user-selectable OVP levels-only specific part numbers like BQ7720501DGKR (4.275 V) or BQ7720502DGKR (4.35 V) offer alternate thresholds.

Does the BQ7720500DGKR support open-wire detection on all five cell inputs?

Yes, the BQ7720500DGKR performs open-wire detection on all five sense inputs (V1 through V5) using a 50-μA pulldown current applied every 128 ms. It detects open-wire conditions by comparing V_n against V_n−1 − 200 mV (for n = 2 to 5) or V1 against VSS + 500 mV. Detection is enabled by default and requires no configuration-only proper RC filtering per the datasheet layout guidelines.

What output drive capability does the BQ7720500DGKR provide on its OUT pin?

The BQ7720500DGKR features an active-low open-drain OUT pin capable of sinking ≥0.3 mA when triggered. It does not source current. The pin must be pulled up externally-either to VDD or another logic rail-to generate a valid high-level signal. Internal pull-up resistance is not present; the device relies entirely on external biasing for logic-level translation.

Can the BQ7720500DGKR be used in a 3-series Li-ion battery pack?

Yes, the BQ7720500DGKR supports 3-series to 5-series Li-ion battery configurations. For a 3S pack, only V1, V2, V3, and VSS are used; V4 and V5 are left unconnected (floating). The device automatically ignores unused higher-order inputs and continues accurate monitoring of the connected cells without configuration changes or performance degradation.

Is Customer Test Mode (CTM) available on the BQ7720500DGKR, and how is it activated?

Yes, Customer Test Mode is available on the BQ7720500DGKR to reduce production-line test time. CTM is activated by applying VDD ≥ V5 + 12 V (minimum 13 V typical) for at least 100 μs. This reduces the overvoltage delay from 1 s to 50 ms, enabling rapid functional verification. CTM exits automatically when the VDD–V5 differential drops below 10 V-no reset pin or command required.