Texas Instruments BQ29415DCTT

Overview

BQ29415DCTT from Texas Instruments is a secondary overvoltage protection IC for 2-, 3-, or 4-cell Li-ion battery packs, featuring fixed 4.60 V per-cell overvoltage threshold, <2 µA supply current, and programmable delay via external capacitor on CD pin. It monitors individual cell voltages (VC1–VC4) and drives an external N-channel FET to blow the fuse during overvoltage events in notebook computers and portable instrumentation.

For engineers reviewing the BQ29415DCTT datasheet, BQ29415DCTT pinout, BQ29415DCTT application, or BQ29415DCTT equivalent, key selection criteria include its precise 4.60 V overvoltage detection voltage, 1.5 s typical delay time with 0.22 µF CD capacitor, MSOP-8 (DCT) package, –40°C to 110°C operating range, and compatibility with 2–4 series Li-ion configurations.

Technical Context

The BQ29415DCTT implements independent voltage monitoring across four sense inputs (VC1–VC4), comparing each cell voltage against a precision internal reference. When any cell exceeds 4.60 V, a 0.18 µA current source charges the external CD capacitor until 1.2 V is reached, triggering OUT high.

It features 80 mV overvoltage detection accuracy over –40°C to 110°C, 320 mV hysteresis, and robust ripple rejection-enabling stable operation during pulse charging. The device remains functional with VDD from 4 V to 25 V and supports differential input ranges up to 8 V between adjacent sense pins.

Key Specifications

Pinout & Package

Package: SSOP-8 (DCT), 3.0 mm × 4.9 mm, 1.3 mm max height, lead pitch 0.65 mm, RoHS-compliant 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 BQ29419PW and BQ29412DCTT, the BQ29415DCTT delivers the highest overvoltage trip point (4.60 V) in the bq2941x family-maximizing usable capacity in high-voltage 4S Li-ion configurations without compromising safety-critical secondary protection integrity.

Availability

BQ29415DCTT is available at Aetrix Electronics and suitable for notebook computers, portable instrumentation, and medical portable devices requiring stable component supply and long-term lifecycle support for battery safety circuits.

Supply support for BQ29415DCTT 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 for industrial, automotive, and personal electronics markets.

The bq2941x product line was designed specifically for secondary overvoltage protection in multi-cell lithium-ion battery packs-providing hardware-based, tamper-resistant safety backup independent of primary battery management systems.

FAQ

What is the overvoltage protection threshold of the BQ29415DCTT?

The BQ29415DCTT has a fixed, factory-trimmed overvoltage protection threshold of 4.60 V per cell. This value is specified across the full operating temperature range (–40°C to 110°C) with ±80 mV accuracy and 320 mV hysteresis. It applies individually to each monitored cell (VC1–VC4), making the BQ29415DCTT suitable for 2-, 3-, or 4-cell Li-ion configurations where precise high-threshold secondary protection is required.

How does the CD pin function on the BQ29415DCTT?

The CD pin on the BQ29415DCTT connects to an external capacitor that sets the overvoltage detection delay time. When any cell exceeds 4.60 V, an internal 0.18 µA current source charges the capacitor. Once the CD pin voltage reaches 1.2 V, the OUT pin transitions high to activate the external fuse-blowing FET. With a 0.22 µF capacitor, the typical delay is 1.5 seconds-allowing transient spikes to settle before triggering irreversible protection.

Can the BQ29415DCTT be used in a 2-cell Li-ion configuration?

Yes, the BQ29415DCTT supports 2-cell configurations. In this setup, VC1 and VC2 are connected together and tied to the top of the 2-cell stack, VC3 is connected to the midpoint (junction of the two cells), and VC4 is connected to the bottom (ground). The device monitors differential voltages VC1–VC2, VC2–VC3, and VC3–VC4 to verify each cell remains below 4.60 V. Full connection guidance is provided in Figure 5 of the SLUS669G datasheet.

What package type and dimensions does the BQ29415DCTT use?

The BQ29415DCTT uses the SSOP-8 (DCT) package: 3.0 mm × 4.9 mm body size, 1.3 mm maximum height, 0.65 mm lead pitch, and 8-pin gull-wing lead form. It is RoHS-compliant with NiPdAu lead finish and meets MSL Level-1 (260°C, unlimited floor life). The pin 1 identifier is located at the top-left corner of the top view, consistent with JEDEC MO-153 variation AA.

Does the BQ29415DCTT require external components to operate?

Yes-the BQ29415DCTT requires at minimum an external capacitor on the CD pin to set overvoltage delay time and an external N-channel MOSFET driven by the OUT pin to blow the fuse. Optional RC filters (RIN/CIN on sense lines, RVD/CVD on VDD) improve noise immunity. No external voltage references, resistors for threshold setting, or microcontroller interface are needed-the BQ29415DCTT operates autonomously as a standalone analog protector.