Texas Instruments BQ29410DCTRG4

Overview

BQ29410DCTRG4 from Texas Instruments is a secondary overvoltage protection IC for 2-, 3-, or 4-cell Li-ion battery packs, featuring fixed 4.35 V overvoltage threshold, programmable delay via external capacitor on CD pin, and ultra-low 2 µA supply current. It monitors individual cell voltages (VC1–VC4), triggers OUT high to activate external fuse-blowing circuitry upon overvoltage, and operates across –40°C to 110°C.

For engineers reviewing the BQ29410DCTRG4 datasheet, BQ29410DCTRG4 pinout, BQ29410DCTRG4 application, or BQ29410DCTRG4 equivalent, this page delivers verified technical context, exact pin functions, real-world use cases in portable instrumentation and notebook battery packs, and validated alternative parts with documented functional differences.

Technical Context

The BQ29410DCTRG4 implements precision per-cell voltage monitoring using internal reference comparison across VC1–VC4 inputs, with ±25 mV overvoltage detection accuracy at 25°C and ±80 mV over full temperature range. Its delay timing is determined by external capacitor on CD pin and internal 0.18 µA current source, yielding 1–2 s delay for 0.22 µF capacitor.

It features high power supply ripple rejection and stable operation during pulse charging, with OUT pin capable of driving ≥40 µA high-level current at 3 V output and sinking ≥5 µA low-level current. The device supports configurable cell configurations (2S–4S) via specific VC pin connection sequences to prevent false triggering.

Key Specifications

Pinout & Package

Package: SSOP-8 (DCT), 3.95 mm × 4.25 mm × 1.3 mm body, 0.65 mm pitch, RoHS-compliant NiPdAu lead 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 BQ29410DCTRG4, BQ29412DCTR offers higher trip voltage for advanced chemistries while maintaining identical timing and drive strength, whereas BQ29419PW provides identical 4.30 V threshold in a more modern TSSOP package with updated moisture handling - both require no schematic change but may need layout revision.

Availability

BQ29410DCTRG4 is available at Aetrix Electronics and suitable for notebook computers, portable instrumentation, and medical portable devices requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for BQ29410DCTRG4 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 experience in battery safety ICs.

The bq2941x product line was designed specifically for redundant overvoltage protection in multi-cell Li-ion battery packs, targeting applications where single-point failure in primary protection must be mitigated by hardware-based secondary supervision.

FAQ

What is the overvoltage protection threshold of the BQ29410DCTRG4?

The BQ29410DCTRG4 has a fixed overvoltage protection threshold of 4.35 V per cell, with ±25 mV accuracy at 25°C and ±80 mV over the full –40°C to 110°C operating range. This value is factory-trimmed and non-adjustable, making it suitable for standard Li-ion cells requiring strict adherence to 4.35 V maximum charge voltage. The BQ29410DCTRG4 does not support external resistor programming of the threshold.

How does the BQ29410DCTRG4 implement programmable delay time?

The BQ29410DCTRG4 uses an internal 0.18 µA current source to charge an external capacitor connected to the CD pin. When the CD pin voltage reaches 1.2 V, the OUT pin asserts high. For a 0.22 µF capacitor, this yields a nominal delay of 1.5 seconds (t_D = 1.2 V × C_DELAY / I_CD). The BQ29410DCTRG4 requires no additional components beyond the capacitor to configure delay, and the timing remains stable across temperature and supply variations.

Can the BQ29410DCTRG4 be used in 2-cell battery configurations?

Yes, the BQ29410DCTRG4 supports 2-cell (2S) configurations by connecting VC1, VC2, and VC3 together to the top of the battery stack, VC4 to the midpoint, and GND to the bottom. TI specifies this connection sequence in the datasheet to ensure correct differential sensing. The BQ29410DCTRG4 maintains full overvoltage detection accuracy in 2S mode, with identical 4.35 V per-cell threshold applied to each monitored node.

What is the function of the OUT pin on the BQ29410DCTRG4?

The OUT pin on the BQ29410DCTRG4 is an open-drain output that transitions from low to high when any monitored cell exceeds 4.35 V. It is designed to drive the gate of an external N-channel MOSFET in the battery's positive rail, enabling fuse-blowing or disconnect functionality. The BQ29410DCTRG4 specifies ≥40 µA high-level drive capability at 3 V output, sufficient to reliably switch typical protection FETs without additional buffering.

Does the BQ29410DCTRG4 require external filtering components?

Yes, the BQ29410DCTRG4 requires external RC filters on both the VC inputs and VDD supply to ensure noise immunity. TI recommends 100 Ω–1 kΩ resistors (RIN) and 0.01–0.1 µF capacitors (CIN) on each VC pin, plus 0–1 kΩ resistor (RVD) and 0.1 µF capacitor (CVD) on VDD. These filters suppress high-frequency noise that could cause false triggering; omitting them compromises the BQ29410DCTRG4's specified ±25 mV accuracy and stability during pulse charging.