Texas Instruments BQ2002DSNTR

Overview

BQ2002DSNTR from Texas Instruments is a CMOS NiCd/NiMH fast-charge controller IC that provides voltage-, temperature-, ∆T/∆t-, and time-based termination for single-cell or multi-cell battery charging. It features open-drain CC and LED outputs, 5.0 V ±20% supply operation, and operates across 0°C to 70°C. It is used in portable medical devices, cordless phones, and rechargeable power tools requiring reliable, low-cost battery management.

For engineers reviewing the BQ2002DSNTR datasheet, BQ2002DSNTR pinout, BQ2002DSNTR application, or BQ2002DSNTR equivalent, key selection criteria include its fixed termination modes (no top-off or pulse-trickle), SOIC-8 package compatibility, 55–440 minute configurable fast-charge timeout, and direct integration with thermistor-based temperature sensing and resistor-divider battery voltage monitoring.

Technical Context

The BQ2002DSNTR implements a state-machine-driven charge control architecture with four independent fast-charge termination conditions: rate-of-temperature-rise (∆T/∆t), maximum cell voltage (2.0 V ±5%), maximum sensed temperature (VTS ≤ 0.225 × VCC), and programmable safety timer (55/110/440 min). It samples TS every 19 s using 16×570 µs averaged ADC conversions to reject 50/60 Hz line ripple.

Unlike the bq2002T variant, the BQ2002DSNTR excludes top-off and pulse-trickle functionality - its TM pin selects only fast-charge timeout and voltage hold-off thresholds. Charge initiation requires either VCC application or BAT voltage falling below 2 V, and fast charge is inhibited if BAT > 2 V or VTS < 0.225 × VCC at startup.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ2002TSNTR, the BQ2002DSNTR removes top-off and pulse-trickle to reduce cost and configuration overhead; compared with MAX713CPA+, it offers tighter voltage reference stability and smaller footprint but supports fewer series cells.

Availability

BQ2002DSNTR is available at Aetrix Electronics and suitable for portable medical devices, cordless power tools, consumer cordless phones, and emergency lighting systems requiring stable component supply and long-term lifecycle support.

Supply support for BQ2002DSNTR 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 delivering analog, embedded processing, and connectivity solutions with emphasis on reliability, longevity, and technical documentation.

The BQ2002DSNTR belongs to TI's battery management IC portfolio designed specifically for cost-sensitive, hardware-based NiCd/NiMH charging in consumer and industrial portable equipment - prioritizing robustness over software configurability.

FAQ

What battery chemistries does the BQ2002DSNTR support?

The BQ2002DSNTR supports nickel-cadmium (NiCd) and nickel-metal hydride (NiMH) battery chemistries exclusively. It is not designed for lithium-based cells. Its termination algorithms - including ∆T/∆t, maximum voltage (2.0 V ±5%), and maximum temperature - are calibrated for the characteristic voltage and thermal profiles of NiCd/NiMH cells. Using BQ2002DSNTR with Li-ion or Li-polymer batteries may result in unsafe charging conditions and is strictly prohibited.

Does the BQ2002DSNTR provide top-off or pulse-trickle charging?

No, the BQ2002DSNTR does not include top-off or pulse-trickle charging functionality. These features are exclusive to the bq2002T variant (e.g., BQ2002TSNTR). The BQ2002DSNTR terminates fast charge using only four methods: rate-of-temperature-rise, maximum cell voltage, maximum temperature, and programmable time-out. After termination, it enters idle or low-power mode - no further charging occurs unless a new cycle is initiated.

How is battery voltage sensed on the BQ2002DSNTR?

The BQ2002DSNTR senses battery voltage via the BAT pin, which accepts a high-impedance (>50 MΩ) resistor-divider network connected across the battery pack. For multi-cell configurations, the divider must scale total pack voltage to represent per-cell voltage - e.g., for a 4-cell NiMH pack, the divider ratio should yield ~2.0 V at BAT when each cell reaches 2.0 V. The datasheet specifies end-to-end divider impedance must be 200 kΩ to 1 MΩ to ensure accuracy and noise immunity.

What is the function of the TM pin on the BQ2002DSNTR?

The TM (Timer Mode) pin on the BQ2002DSNTR is a three-level analog input that configures the fast-charge safety timer (55/110/440 min), voltage hold-off threshold, and termination sensitivity. A low voltage (≈0 V) selects 2C rate (55 min), mid-level (≈2.5 V) selects C/4 rate (440 min), and high voltage (≈5 V) selects 1C rate (110 min). Unlike the bq2002T, TM on BQ2002DSNTR does not affect top-off or trickle settings - those are absent in this variant.

Can the BQ2002DSNTR be used with multi-cell NiMH battery packs?

Yes, the BQ2002DSNTR can manage multi-cell NiMH packs, but only when the BAT pin is connected to a properly scaled resistor-divider network that presents per-cell voltage. For example, a 4-cell pack (nominal 4.8 V) must be divided to deliver ~2.0 V at BAT when each cell reaches 2.0 V. The IC monitors only this scaled value - it does not detect cell count or balance. Thermal sensing via TS must also reflect average pack temperature, typically using a single NTC thermistor mounted centrally.