Texas Instruments BQ2002CPN

Overview

BQ2002CPN from Texas Instruments is a CMOS NiCd/NiMH fast-charge controller IC in 8-pin DIP package, featuring -∆V and peak voltage (PVD) termination, temperature cutoff at 0.5×VCC, maximum charge time limits of 40–160 minutes depending on TM pin setting, and open-drain CC/LED outputs for charge control and status indication. It enables cost-effective single-cell or multi-cell battery charging in portable medical devices, cordless phones, and power tools.

For engineers reviewing the BQ2002CPN datasheet, BQ2002CPN pinout, BQ2002CPN application, or BQ2002CPN equivalent, key selection considerations include its three-level TM pin configuration for safety timer/voltage hold-off/pulse-trickle rate selection, synchronized voltage sampling via INH pin, and dual termination modes (-∆V vs PVD) with ±3 mV detection tolerance.

Technical Context

The BQ2002CPN implements a state-machine-based charge controller with five independent fast-charge termination conditions: negative delta voltage (-∆V), peak voltage detection (PVD), maximum cell voltage (2 V ±5%), maximum temperature (via TS input threshold VTCO = 0.5×VCC ±5%), and programmable maximum time (C/2, 1C, or 2C rates). Its internal band-gap reference ensures stable voltage thresholds across temperature and supply variation.

Voltage sampling for PVD/-∆V is configurable as free-running (every 17 s) or externally synchronized via INH pulses; it performs 32 measurements in PVD mode and 16 in -∆V mode, yielding effective filtering against 50/60 Hz line ripple. The TM pin selects not only timing but also pulse-trickle rate (C/32), pulse width (18–73 ms), and voltage hold-off duration to prevent false termination on aging batteries.

Key Specifications

Pinout & Package

Package: 8-pin 300-mil plastic DIP (PN), 0.300" wide, through-hole mount; RoHS-compliant, lead finish NIPDAU, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ2002CPN, BQ2002CSN offers identical functionality in a surface-mount package ideal for modern production, while MAX713 provides a less flexible, fixed-function alternative lacking programmable timing, dual termination modes, and noise-immune voltage sampling - making BQ2002CPN the optimal choice for robust, field-deployable NiCd/NiMH charging systems.

Availability

BQ2002CPN is available at Aetrix Electronics and suitable for portable power tools, cordless telephony, medical monitoring devices, and emergency lighting systems requiring stable component supply and long-lifecycle support.

Supply support for BQ2002CPN 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 headquartered in Dallas, Texas, delivering analog, embedded processing, and connectivity solutions since 1930.

The BQ2002CPN belongs to TI's battery management IC portfolio designed specifically for cost-sensitive, high-reliability NiCd/NiMH charging applications where hardware-based safety and minimal external components are critical.

FAQ

What termination methods does the BQ2002CPN support for NiCd/NiMH fast charging?

The BQ2002CPN supports five independent fast-charge termination methods: negative delta voltage (-∆V), peak voltage detection (PVD), maximum cell voltage (2 V ±5%), maximum temperature (via TS input threshold VTCO = 0.5×VCC ±5%), and programmable maximum time (configurable via TM pin for C/2, 1C, or 2C rates). All operate concurrently, and fast charge terminates upon detection of any one condition - ensuring robust safety without reliance on a single parameter. This multi-layered approach is integral to the BQ2002CPN's reliability in unattended charging applications.

How does the TM pin configure the BQ2002CPN's behavior?

The TM pin is a three-level analog input (low/mid/high) that simultaneously configures the fast-charge safety timer (40/80/160 min), voltage termination mode (-∆V or PVD), pulse-trickle rate (C/32), pulse width (18–73 ms), and voltage hold-off duration (75–300 ms). A mid-level setting (VCC/2 ±0.5 V) is implemented using a resistor divider between VCC and VSS. This single-pin configurability eliminates external jumpers or firmware, making the BQ2002CPN adaptable to diverse battery chemistries and form factors without redesign - a core advantage of the BQ2002CPN architecture.

Can the BQ2002CPN be used for multi-cell NiMH battery packs?

Yes, the BQ2002CPN can manage multi-cell NiMH packs when used with an appropriate resistor divider on the BAT pin. The datasheet specifies RB1/RB2 = N − 1, where N is the number of series cells, to scale the total pack voltage down to a valid single-cell-equivalent range (0.175×VCC ±20% to 2 V ±5%). Input impedance must remain ≥200 kΩ and <1 MΩ. Temperature sensing remains per-pack via a single NTC thermistor. This scaling method is validated and explicitly supported in the BQ2002CPN's functional description and Figure 1.

What is the purpose of the INH pin on the BQ2002CPN?

The INH pin on the BQ2002CPN is an active-high charge inhibit input that suspends fast-charge activity and freezes the internal safety timer while preserving pulse-trickle operation and temperature monitoring. When INH returns low, the BQ2002CPN resumes fast charging from the exact point of suspension - including remaining timer value and voltage/temperature history. This enables external system-level control (e.g., MCU or power sequencer) to pause charging without resetting safety logic, a capability confirmed in the BQ2002CPN's "Charge Inhibit" section and Figure 2 state diagram.

Does the BQ2002CPN include an internal voltage reference?

Yes, the BQ2002CPN integrates a precision internal band-gap voltage reference used for all critical analog comparisons: VMCV (2 V), VTCO (0.5×VCC), VHTF (0.6×VCC), and -∆V/PVD detection thresholds. This eliminates dependency on external references or supply-rail stability for termination accuracy. The reference ensures ±5% tolerance on VMCV and VTCO, and ±3 mV on -∆V detection - specifications verified in the "DC Thresholds" table of the BQ2002CPN datasheet and central to its repeatable performance across temperature and voltage variation.