Texas Instruments BQ25101YFPT

Overview

BQ25101YFPT from Texas Instruments is a 250-mA single-cell Li-ion linear battery charger IC in a 1.60 mm × 0.90 mm DSBGA-6 package, featuring 4.20 V regulation voltage, 1% charge voltage accuracy, 10% charge current accuracy, and ultra-low 75 nA battery leakage current. It supports USB/adapter input (up to 6.5 V), JEITA-compliant temperature monitoring via TS pin, and programmable 1–250 mA fast-charge current using an external ISET resistor.

For engineers reviewing the BQ25101YFPT datasheet, BQ25101YFPT pinout, BQ25101YFPT application, or BQ25101YFPT equivalent, key selection considerations include its CHG open-drain status indicator, PRE-TERM dual-function pin for precharge/termination threshold programming, 10-hour safety timer with TTDM mode for absent-battery operation, and compatibility with low-power wearable systems requiring minimal board space and high battery preservation.

Technical Context

The BQ25101YFPT implements a three-phase linear charging algorithm-preconditioning (below 2.5 V), constant-current fast charge, and constant-voltage regulation-fully integrated with thermal regulation at 125°C and shutdown at 150°C. Its input overvoltage protection triggers at 6.67 V with 110 mV hysteresis and 113 µs blanking time.

JEITA-compliant temperature sensing is enabled via the TS pin, supporting cold/hot thresholds (e.g., 268 mV at 45°C) and automatic charge suspension outside ±10°C to ±60°C range. Unlike the bq25100 series, BQ25101YFPT uses the CHG pin (not PRE-TERM) as the primary charge-status output, while PRE-TERM exclusively configures precharge and termination currents.

Key Specifications

Pinout & Package

Package: 6-pin DSBGA (YFP), 1.60 mm × 0.90 mm, 0.4-mm pitch, bottom-side solder balls.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar single-cell Li-ion linear charger applications.

Compared with BQ25101YFPT, BQ25100YFPT lacks JEITA temperature profiling and uses a different status signaling method, while MCP73831T-2DCI/OT offers higher current but sacrifices leakage performance and thermal safety - making BQ25101YFPT optimal for space-constrained, safety-critical wearables.

Availability

BQ25101YFPT is available at Aetrix Electronics and suitable for fitness trackers, smartwatches, and wireless earbud cases requiring stable component supply, long-term lifecycle support, and guaranteed authentic TI-sourced parts.

Supply support for BQ25101YFPT 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 and embedded processing technologies, with decades of expertise in power management IC design and manufacturing.

The bq2510x product line was engineered specifically for ultra-low-power, space-constrained portable electronics - delivering high integration, precision charging, and robust safety in sub-1 mm² packages for wearables and medical sensors.

FAQ

What is the recommended ISET resistor value for 100 mA fast-charge current with BQ25101YFPT?

The BQ25101YFPT uses KISET = 135 A·Ω (typical) to calculate ISET resistance: RISET = KISET / ICHG. For 100 mA, RISET = 135 / 0.1 = 1.35 kΩ. A 1.35 kΩ ±1% resistor yields 100 mA ±10% fast-charge current, matching the device's specified accuracy. This value is confirmed in Section 7.5 of the SLUSBV8C datasheet.

Does BQ25101YFPT support JEITA-compliant charging, and how is it configured?

Yes, BQ25101YFPT supports full JEITA temperature profiling via the TS pin connected to a 10-kΩ NTC thermistor. It automatically suspends charging below 0°C (cold) and above 60°C (disable), and reduces charge current between 45–60°C (hot). Thresholds - e.g., 268 mV at 45°C - are factory-trimmed and require no configuration beyond proper NTC selection and layout per Section 9.2 of the datasheet.

How does the TTDM (Timer Termination Disable Mode) function in BQ25101YFPT?

In BQ25101YFPT, TTDM activates when the TS pin voltage exceeds 1.6 V (e.g., battery removed or TS floating), disabling the 10-hour safety timer and holding the charger in standby. This prevents false timeout faults during battery replacement or manufacturing test. Recovery occurs when TS drops below 1.5 V, re-enabling normal charge sequencing - behavior verified in Section 8.4 of SLUSBV8C.

What is the absolute maximum battery leakage current specification for BQ25101YFPT?

The BQ25101YFPT specifies a maximum battery leakage current of 75 nA at TJ = 0–125°C with VIN = 0 V (Section 7.5, "Quiescent Current"). This ultra-low value is measured at the OUT pin and represents total IC-related discharge - critical for multi-year shelf life in disposable medical patches and infrequently used IoT sensors.

Can BQ25101YFPT be used without a thermistor, and what is the safe default configuration?

Yes, BQ25101YFPT can operate without a thermistor: tie TS to VSS through a 10-kΩ resistor to disable JEITA and enable continuous charging. This configuration bypasses all temperature thresholds while retaining OVP, thermal regulation (125°C), and safety timers. It is explicitly validated in Section 6 ("Pin Functions") and Figure 22 of the SLUSBV8C datasheet.