Texas Instruments BQ2057WTSTR

Overview

BQ2057WTSTR from Texas Instruments is a linear lithium-ion/lithium-polymer charge management IC for dual-cell (8.4 V) battery packs. It integrates voltage regulation (±1% accuracy), current regulation (programmable via external sense resistor), AutoComp™ dynamic impedance compensation, temperature-monitored charge qualification, and automatic recharge. It drives external PNP or P-channel MOSFET pass devices in portable medical equipment and telematics control units.

For engineers reviewing the BQ2057WTSTR datasheet, BQ2057WTSTR pinout, BQ2057WTSTR application, or BQ2057WTSTR equivalent, this page delivers verified technical context, real-world charge-phase behavior, thermal performance data, and validated alternative options for dual-cell Li-ion charging designs requiring safety-critical temperature supervision and low-dropout operation.

Technical Context

The BQ2057WTSTR implements a three-phase linear charge algorithm: preconditioning (10% of regulation current at ≤3.06 V), constant-current regulation (via high- or low-side sensing with 103.6–137.5 mV threshold), and constant-voltage regulation (8.40 V ±1% over −20°C to 70°C). It uses internal reference tracking and VCC-referenced TS input for thermistor-based temperature monitoring with V(TS1) = 30% VCC and V(TS2) = 60% VCC thresholds.

Charge termination occurs at I(TERM) = −14 mV (relative to VCC or VSS), and automatic recharge triggers when battery voltage falls below VO(REG) − 200 mV. The CC pin operates as a source-follower output driving external pass transistors, while STAT provides three-state status (high = charging, low = done, Hi-Z = fault/sleep).

Key Specifications

Pinout & Package

TSSOP-8 (TS) package: 3.00 mm × 4.40 mm body, exposed pad not specified, RoHS-compliant lead finish.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-cell Li-ion linear charge management applications.

Compared with BQ2057TTSR, BQ2057WTSTR provides higher regulation voltage for modern Li-ion cells and identical thermal safety architecture; versus MCP73871-FCI/OT, it offers higher current capability, external pass-device control, and AutoComp™-enabled faster charging-critical for industrial and medical systems demanding long-term reliability.

Availability

BQ2057WTSTR is available at Aetrix Electronics and suitable for portable medical equipment, telematics control units, and emergency call systems requiring stable component supply, long-lifecycle support, and consistent thermal safety compliance.

Supply support for BQ2057WTSTR 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 over 50 years of innovation in precision analog ICs.

The BQ2057 series belongs to TI's battery management portfolio, designed specifically for cost-sensitive, compact linear charging applications in portable electronics where safety, accuracy, and minimal external component count are critical.

FAQ

What is the exact charge regulation voltage of the BQ2057WTSTR?

The BQ2057WTSTR has a fixed charge regulation voltage of 8.40 V with ±1% accuracy over −20°C to 70°C operating temperature and full supply voltage range. This value is factory-trimmed and confirmed in the Electrical Characteristics table of the SLUS025G datasheet under VO(REG) for BQ2057W variants. It is intended for dual-cell Li-ion and Li-polymer battery packs requiring precise full-charge termination.

Does the BQ2057WTSTR support both high-side and low-side current sensing?

Yes, the BQ2057WTSTR supports both high-side and low-side current sensing configurations via its SNS pin. For high-side sensing, the sense resistor connects between VCC and SNS; for low-side, it connects between VSS and SNS. The datasheet specifies distinct V(SNS) thresholds for each mode-103.6–137.5 mV for high-side and 108.1–143 mV for low-side-enabling layout flexibility without additional components.

How does the AutoComp™ feature function in the BQ2057WTSTR?

The AutoComp™ feature in the BQ2057WTSTR dynamically adjusts the voltage regulation setpoint during charging using the COMP pin input. With a gain of 2.09–2.76 V/V, it compensates for rising battery internal impedance, reducing overall charge time while maintaining safety. This is implemented via internal analog circuitry and requires no external controller or firmware-confirmed in Section 9.3.6 and Table 8-5 of the SLUS025G datasheet.

What happens when the battery temperature is outside the allowed range in the BQ2057WTSTR?

When the TS pin voltage falls outside the V(TS1) = 30% VCC to V(TS2) = 60% VCC window, the BQ2057WTSTR suspends charging and drives the STAT pin to Hi-Z state. This indicates a temperature fault condition to the host system or LED indicator. Charging resumes automatically only after the TS voltage re-enters the valid range-ensuring compliance with JEITA and IEC 62133 thermal safety requirements for Li-ion batteries.

Is the BQ2057WTSTR pin-compatible with other BQ2057x variants in TSSOP-8?

Yes, the BQ2057WTSTR shares identical pinout, package dimensions, and electrical interface with all BQ2057x variants in TSSOP-8 (TS) packaging-including BQ2057TTSR, BQ2057CTS, and BQ2057SN-as confirmed in Figures 7-1 and 7-2 and Table 7-1 of the SLUS025G datasheet. Only the regulation voltage and minor trim parameters differ; no PCB layout changes are needed when substituting within the same package type.