Texas Instruments BQ2057TTSG4

Overview

BQ2057TTSG4 from Texas Instruments is a linear lithium-ion battery charge management IC for dual-cell (8.2 V) Li-ion/Li-pol packs, featuring ±1% voltage regulation accuracy, 0.3-V dropout, AutoComp™ dynamic impedance compensation, integrated current/voltage regulation, and temperature-monitored charge control in an 8-pin TSSOP package. It enables compact, cost-sensitive portable medical devices and telematics units.

For engineers reviewing the BQ2057TTSG4 datasheet, BQ2057TTSG4 pinout, BQ2057TTSG4 application, or BQ2057TTSG4 equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternative options with functional distinctions, and supply-chain support details specific to BQ2057TTSG4 - not generic BQ2057 family data.

Technical Context

The BQ2057TTSG4 implements a three-phase linear charging algorithm-conditioning (10% of I_REG), constant-current, and constant-voltage-with automatic recharge at V(RCH) = V_O(REG) − 200 mV. It supports high- or low-side current sensing via external R_SNS, with V(SNS) thresholds of 103.6–137.5 mV depending on configuration.

Temperature monitoring uses the TS pin referenced to VCC/2 thresholds (V(TS1) = 30% VCC, V(TS2) = 60% VCC), enabling safe inhibit outside 0°C–50°C battery range. The CC pin drives external PNP or P-channel MOSFET pass devices, while STAT provides 3-state status (High = charging, Low = done, Hi-Z = fault/sleep).

Key Specifications

Pinout & Package

Package: 8-pin TSSOP (TS), body size 3.00 mm × 4.40 mm, exposed pad not specified, RoHS-compliant.

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 BQ2057TTSG4, BQ2057WTSG4 offers higher regulation voltage for 4.2 V/cell chemistries but no functional differentiation otherwise, while MCP73871-FCI/OT trades AutoComp™ and pin compatibility for improved voltage accuracy and integrated gate drive - making it suitable only for new designs prioritizing precision over adaptive charge optimization.

Availability

BQ2057TTSG4 is available at Aetrix Electronics and suitable for emergency call systems, portable medical equipment, and aftermarket telematics requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for BQ2057TTSG4 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 for industrial, automotive, and personal electronics markets.

The BQ2057 series was designed specifically for cost-sensitive, space-constrained portable Li-ion/Li-pol charging applications - emphasizing minimal external components, thermal efficiency, and integrated safety features like temperature-monitored preconditioning and automatic recharge.

FAQ

What is the exact charge regulation voltage of the BQ2057TTSG4?

The BQ2057TTSG4 has a fixed charge regulation voltage of 8.2 V with better than ±1% accuracy over −20°C to 70°C ambient temperature and full VCC operating range. This value is factory-trimmed and does not require external resistor networks - it is specifically configured for dual-cell Li-ion packs rated at 4.1 V per cell. The BQ2057TTSG4 datasheet confirms VO(REG) = 8.119 V (min), 8.20 V (typ), 8.282 V (max) under standard test conditions.

Does the BQ2057TTSG4 support both high-side and low-side current sensing?

Yes, the BQ2057TTSG4 supports both high-side and low-side current sensing configurations without additional components. For high-side sensing, the sense resistor connects between VCC and SNS; for low-side, it connects between VSS and SNS. The BQ2057TTSG4 uses different V(SNS) thresholds - 103.6–137.5 mV for high-side and 108.1–143 mV for low-side - to maintain regulation accuracy in either topology, as specified in Section 8.5 of the SLUS025G datasheet.

How does the AutoComp™ feature in the BQ2057TTSG4 reduce charge time?

The AutoComp™ feature in the BQ2057TTSG4 reduces charge time by dynamically increasing the regulation voltage during the constant-voltage phase to offset rising battery internal impedance. With a gain of 2.2 V/V, it adjusts VO(REG) in real time based on sensed charge current, allowing more current to flow later in the CV phase. TI application data shows this delivers up to 15% faster full charge in aged or high-impedance dual-cell packs compared to fixed-voltage linear chargers like the BQ2057TTSG4 without AutoComp™ enabled.

What happens when the battery temperature is outside the valid range for the BQ2057TTSG4?

When the TS pin voltage falls outside the 30%–60% VCC window - corresponding to invalid battery temperature - the BQ2057TTSG4 suspends charging and drives the STAT pin to high-impedance (Hi-Z) state. This condition persists until the thermistor network restores TS voltage within thresholds. The BQ2057TTSG4 does not attempt trickle or timer-based recovery; it waits for valid temperature input before resuming the charge cycle, ensuring compliance with IEC 62133 thermal safety requirements.

Can the BQ2057TTSG4 be used with a P-channel MOSFET instead of a PNP transistor?

Yes, the BQ2057TTSG4 is explicitly designed to drive both PNP bipolar transistors and P-channel MOSFETs via its CC pin. The CC output operates as a source-follower with 40 mA sink capability, compatible with common logic-level P-channel devices like the SI6475DQ. Figure 10-4 in the BQ2057TTSG4 datasheet provides a validated schematic using a P-channel MOSFET, confirming gate-drive compatibility, thermal performance, and stable regulation under load.