Texas Instruments BQ2002GSN

Overview

BQ2002GSN from Texas Instruments is a CMOS NiCd/NiMH fast-charge management IC in an 8-pin SOIC package, featuring -∆V and peak voltage (PVD) termination, maximum temperature cutoff at 0.5×VCC, and configurable top-off timing up to 160 minutes for C/2 rate charging - used in portable medical devices, cordless power tools, and consumer battery packs.

For engineers reviewing the BQ2002GSN datasheet, BQ2002GSN pinout, BQ2002GSN application, or BQ2002GSN equivalent, key selection criteria include its dual-termination safety logic (-∆V/PVD), open-drain CC output for external MOSFET control, LED status indication, TM pin-based configuration of charge timers and hold-off periods, and compatibility with thermistor-based temperature monitoring.

Technical Context

The BQ2002GSN implements a state-driven charge controller with five independent termination conditions: -∆V (–12 mV ±3 mV), PVD (–2.5 mV ±2.5 mV), maximum cell voltage (2 V ±5%), maximum temperature (VTS < 0.5×VCC), and programmable time limits (40–160 min depending on TM setting and charge rate). It uses synchronized voltage sampling triggered by INH pulses to reject 50/60 Hz line ripple.

Its analog front end includes high-impedance BAT input (≥50 MΩ), TS thermistor interface, and internal band-gap reference; digital logic manages fast-charge initiation, top-off modulation (73 ms active / 1097 ms inactive), and pulse-trickle (C/32 every 1.17 s). Low-power mode activates when VBAT ≥ VCC – 1.5 V, reducing ICC to <1 µA.

Key Specifications

Pinout & Package

Package: 8-pin narrow SOIC (SOIC-D, 150-mil width), 1.75 mm max height, RoHS-compliant NIPDAU lead finish, MSL Level-1 (260°C reflow).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NiCd/NiMH charge management applications.

Compared with BQ2002ESN, the BQ2002GSN offers shorter but more precise fast-charge windows and selectable -∆V/PVD modes; versus MAX713CPA+, it provides tighter voltage regulation, lower quiescent current, and integrated timing - at the cost of narrower input voltage range.

Availability

BQ2002GSN is available at Aetrix Electronics and suitable for portable medical devices, cordless power tools, and consumer battery packs requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for BQ2002GSN 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.

The BQ2002GSN belongs to TI's bq2002 family of standalone NiCd/NiMH charge controllers, designed specifically for cost-sensitive, MCU-free charging applications in portable and industrial equipment where safety, reliability, and minimal external components are critical.

FAQ

What termination methods does the BQ2002GSN support for NiCd/NiMH fast charging?

The BQ2002GSN supports five independent fast-charge termination methods: negative delta voltage (-∆V) detection at –12 mV ±3 mV, peak voltage detection (PVD) at –2.5 mV ±2.5 mV, maximum cell voltage (2 V ±5%), maximum temperature (VTS < 0.5×VCC), and programmable maximum time (40–160 min). All are enforced simultaneously, and fast charge ends upon the first condition met. This multi-layered approach ensures robust safety across varying battery chemistries and aging states in the BQ2002GSN.

How does the TM pin configure BQ2002GSN behavior?

The TM pin is a three-level analog input (low/mid/high) that configures multiple BQ2002GSN functions: fast-charge safety timer limits (40/80/160 min), top-off duration, PVD vs. -∆V termination mode, voltage hold-off period, and pulse-trickle rate. For example, TM = high selects -∆V mode and 40-min fast-charge timeout for 2C rate. The mid-level (VCC/2 ±0.5 V) is generated using a resistor divider, and each level maps directly to values in Table 1 of the BQ2002GSN datasheet.

Can BQ2002GSN operate with multi-cell NiCd/NiMH batteries?

Yes - the BQ2002GSN monitors single-cell voltage via the BAT pin, so multi-cell packs require a resistor divider to scale total pack voltage down to ≤2 V per cell. For an N-cell pack, RB1/RB2 = N – 1 ensures correct scaling; total divider impedance must be 200 kΩ–1 MΩ. Temperature sensing remains per-pack via a single NTC thermistor near the battery stack. This architecture allows the BQ2002GSN to manage 2–12 cell NiCd/NiMH configurations with appropriate external components.

What is the function of the INH pin on the BQ2002GSN?

The INH pin is an active-high charge inhibit input that suspends fast charge and top-off activity while preserving the internal timer state and continuing pulse-trickle charging. When INH goes high, the CC output halts modulation and the LED pin freezes its current state. Upon return to low, the BQ2002GSN resumes exactly where it left off - including remaining top-off time and voltage history for -∆V/PVD decisions. This enables host-controlled charge pauses without losing context or requiring reset.

Does BQ2002GSN support low-power or shutdown modes?

Yes - the BQ2002GSN enters low-power mode automatically when VBAT ≥ VCC – 1.5 V (VPD threshold), driving both CC and LED outputs to high-Z and reducing supply current to <1 µA. In this state, the device remains responsive to BAT voltage drops or INH transitions. When VBAT falls below VPD, it exits shutdown and initiates pulse-trickle until a valid charge cycle begins. This feature makes the BQ2002GSN suitable for always-on battery backup systems where ultra-low quiescent current is essential.