Texas Instruments BQ2057PDGK

Overview

BQ2057PDGK from Texas Instruments is a linear lithium-ion/lithium-polymer charge management IC for single-cell (4.2 V) or dual-cell (8.4 V) battery packs, featuring ±1% voltage regulation accuracy, 0.3-V dropout voltage, AutoComp™ dynamic impedance compensation, integrated current/voltage regulation, and programmable charge-current with high- or low-side sensing.

For engineers reviewing the BQ2057PDGK datasheet, BQ2057PDGK pinout, BQ2057PDGK application, or BQ2057PDGK equivalent, this device supports compact, cost-sensitive portable electronics requiring precise thermal-aware charging, automatic precharge for deeply discharged cells, and host-processor or LED-based charge-status indication without external op-amps or discrete logic.

Technical Context

The BQ2057PDGK implements a three-phase linear charging algorithm-battery conditioning (precharge at ~10% of regulation current), constant-current, then constant-voltage-with temperature-inhibited start-up using an external NTC/PTC thermistor network referenced to VCC. It uses internal reference-based voltage regulation and current-sense feedback via SNS pin to maintain fixed output voltages (4.2 V or 8.4 V variants) across −20°C to 70°C.

Charge termination occurs at I(TERM) = −4 mV to −30 mV (relative to VCC or VSS depending on sensing configuration), and automatic recharge triggers when battery voltage falls below VO(REG) − 100 mV (for 4.2 V) or VO(REG) − 200 mV (for 8.4 V). The CC pin drives external PNP or P-channel MOSFET pass devices, while STAT provides 3-state open-drain status signaling.

Key Specifications

Pinout & Package

Package: MSOP-8 (DGK), 3.00 mm × 3.00 mm body, exposed pad optional per TI design guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ2057PDGK, BQ2057CTS offers identical functionality but demands layout rework for pin compatibility, while BQ24013DRCR sacrifices dual-cell support and AutoComp™ for monolithic integration - making BQ2057PDGK optimal for thermally constrained, dual-voltage, or legacy-compatible linear charger implementations.

Availability

BQ2057PDGK is available at Aetrix Electronics and suitable for emergency call systems, portable medical equipment, EPOS card readers, and gaming accessories requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for BQ2057PDGK 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 company specializing in analog, embedded processing, and power management technologies, with decades of leadership in battery management ICs.

The BQ2057 series was designed specifically for cost-sensitive, space-constrained portable electronics needing high-accuracy linear charging without complex external circuitry - targeting telematics, medical, and consumer accessories markets.

FAQ

What is the exact regulation voltage tolerance of the BQ2057PDGK over temperature and supply voltage?

The BQ2057PDGK delivers better than ±1% voltage regulation accuracy across its full operating range of −20°C to 70°C and VCC from 4.5 V to 15 V. This specification applies specifically to the BQ2057C variant (4.2 V nominal), with measured values spanning 4.158 V to 4.242 V at 25°C and holding tight tolerance across thermal and supply variations - critical for maximizing Li-ion cell capacity and cycle life in the BQ2057PDGK application.

Does the BQ2057PDGK support dual-cell (8.4 V) battery charging?

No - the BQ2057PDGK is the 4.2 V variant (BQ2057C) in MSOP-8 DGK package. Dual-cell operation requires the BQ2057W variant (8.4 V), which is only offered in SOIC and TSSOP packages (e.g., BQ2057WTS), not DGK. The BQ2057PDGK pinout, thermal design, and internal voltage reference are fixed for single-cell 4.2 V Li-ion/Li-pol systems.

How does the BQ2057PDGK implement temperature monitoring without external op-amps?

The BQ2057PDGK integrates dual comparators with VCC-referenced thresholds (29.1–61.8% VCC) on the TS pin, accepting direct voltage from a simple two-resistor + thermistor divider. No external amplification or level-shifting is needed because both the thermistor network and internal thresholds scale with VCC - ensuring stable trip points across input voltage variation, a key design feature confirmed in the BQ2057PDGK datasheet Section 9.3.3.

Can the BQ2057PDGK be used with a P-channel MOSFET instead of a PNP transistor?

Yes - the BQ2057PDGK CC pin is explicitly designed to drive either a PNP bipolar transistor or a P-channel MOSFET, as verified in Figures 10-1 and 10-4 of the official datasheet. Its source-follower output structure provides sufficient gate-drive current and voltage swing to fully enhance common logic-level P-channel devices like the SI6475DQ, making the BQ2057PDGK compatible with both topologies without redesign.

What is the minimum external component count required for basic BQ2057PDGK operation?

A functional BQ2057PDGK charger requires only five external components: one current-sense resistor (e.g., 0.2 Ω), one PNP or P-channel pass device, one thermistor + two divider resistors (optional if temperature disable is acceptable), and one 0.1-µF bypass capacitor on VCC. No external op-amps, references, or timing capacitors are needed - fulfilling the "small number of external components" claim in the BQ2057PDGK feature list.