Texas Instruments BQ29415DCTR

Overview

BQ29415DCTR from Texas Instruments is a secondary overvoltage protection IC for 2-, 3-, or 4-cell Li-ion battery packs, providing fixed 4.60 V per-cell overvoltage detection with ±80 mV accuracy across –40°C to 110°C, programmable delay via external capacitor on CD pin, and low 2 µA supply current. It drives an external N-channel FET to blow a fuse in the positive battery rail during overvoltage events.

For engineers reviewing the BQ29415DCTR datasheet, BQ29415DCTR pinout, BQ29415DCTR application, or BQ29415DCTR equivalent, this device serves as second-level cell voltage protection in portable instrumentation, notebook computers, and high-reliability battery packs where precision threshold stability and pulse-charge immunity are required.

Technical Context

The BQ29415DCTR implements independent per-cell voltage monitoring using precision internal reference circuitry, comparing VC1–VC2, VC2–VC3, VC3–VC4, and VC4–GND against a fixed 4.60 V threshold. Detection triggers a 0.18 µA current source charging the CD pin capacitor; output activation occurs at 1.2 V on CD.

It features high power supply ripple rejection and stable operation during pulse charge, with hysteresis of 320–450 mV to prevent oscillation near threshold. The OUT pin delivers 1 mA high-level drive capability and sinks 5 µA at low level, enabling direct interface with external protection FET gate drivers.

Key Specifications

Pinout & Package

Package: 8-pin MSOP (DCT), 3.0 mm × 3.0 mm × 1.0 mm body, lead pitch 0.65 mm, RoHS-compliant CU-NiPdAu finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ29415DCTR, BQ29419PW offers reduced threshold and different package, while BQ29414DCTR provides a 50 mV lower trip point in identical form factor-both serve distinct voltage-margin requirements without altering system timing or drive behavior.

Availability

BQ29415DCTR is available at Aetrix Electronics and suitable for notebook computer battery packs, portable instrumentation power systems, and industrial handheld data collectors requiring stable component supply with long-term lifecycle support.

Supply support for BQ29415DCTR 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 company delivering analog and embedded processing solutions, with leadership in power management and battery protection ICs since the 1990s.

The bq2941x family was designed specifically for secondary overvoltage protection in multi-cell Li-ion battery packs, targeting applications where hardware-based redundancy and high-accuracy voltage thresholds are mandatory for safety certification.

FAQ

What is the exact overvoltage detection threshold of the BQ29415DCTR?

The BQ29415DCTR has a fixed overvoltage detection threshold of 4.60 V per cell, with maximum accuracy error of ±80 mV over the full operating temperature range (–40°C to 110°C). This value is factory-trimmed and does not require external components or calibration. The BQ29415DCTR datasheet specifies this threshold unambiguously in the Electrical Characteristics table under V(PROTECT).

Can the BQ29415DCTR be used in a 2-cell Li-ion configuration?

Yes, the BQ29415DCTR supports 2-, 3-, and 4-cell configurations. In a 2-cell setup, VC1 and VC2 are tied together and connected to the top of the stack, VC3 connects to the mid-node, and VC4 connects to the bottom node (cathode of cell 2). The BQ29415DCTR functional diagram and Figure 5 in the datasheet confirm this connection method.

What is the purpose of the CD pin on the BQ29415DCTR?

The CD pin on the BQ29415DCTR accepts an external capacitor to set the overvoltage detection delay time. An internal 0.18 µA current source charges this capacitor; when voltage reaches 1.2 V, the OUT pin activates. For example, a 0.22 µF capacitor yields a 1–2 second delay, as specified in the Recommended Operating Conditions table for td(CD).

Is the BQ29415DCTR pin-compatible with other bq2941x variants?

Yes, all bq2941x devices-including BQ29415DCTR, BQ29414DCTR, and BQ29410DCTR-are pin-compatible in the DCT-8 package. Terminal functions (VC1, VC2, GND, etc.) and pin numbering match exactly across the family, enabling drop-in replacement solely by changing the overvoltage threshold variant.

Does the BQ29415DCTR require external passive components for basic operation?

The BQ29415DCTR requires only two external components for core functionality: a capacitor on the CD pin to set delay time and optionally RC filters (RIN/CIN) on voltage sense inputs for noise immunity. No external resistors are needed for threshold setting, as the 4.60 V reference is internal and factory-trimmed-confirmed in the Functional Block Diagram and Applications section of the BQ29415DCTR datasheet.