Texas Instruments BQ25122YFPR

Overview

BQ25122YFPR from Texas Instruments is a highly integrated battery charge management IC for ultra-low-power wearables, featuring a 300-mA buck regulator (1.2-V default), 700-nA quiescent current with buck enabled, configurable load switch or 100-mA LDO, 0.5% accurate 3.6–4.65-V battery voltage regulation, and 500-µA minimum termination current. It enables power path management and ship mode with <150-nA battery quiescent current in hearing aids and smart watches.

For engineers reviewing the BQ25122YFPR datasheet, BQ25122YFPR pinout, BQ25122YFPR application, or BQ25122YFPR equivalent, key selection considerations include I²C-programmable charge voltage/current, JEITA-compliant TS thermistor monitoring, push-button wake/reset timers, and 2.5-mm × 2.5-mm DSBGA-25 package integration for space-constrained hearables.

Technical Context

The BQ25122YFPR implements a DC/DC buck converter using DCS-Control topology to sustain high efficiency down to 10-µA loads, paired with a linear charger supporting precharge, constant-current, and constant-voltage phases. Its power path architecture allows simultaneous system powering and battery charging while enabling ship mode via dedicated CD and MR pins.

I²C interface provides full programmability of charge voltage (3.6–4.65 V), charge current (5–300 mA), termination threshold (0.5–37 mA), input current limit (50–400 mA), SYS output (1.1–3.3 V), and LS/LDO output (0.8–3.3 V). JEITA-compatible TS monitoring uses four NTC thresholds with deglitching for safe temperature-based charge control.

Key Specifications

Pinout & Package

Package: 2.5 mm × 2.5 mm DSBGA-25 (YFP) with 0.4-mm pitch, bottom-side solder balls.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery charge management applications.

Compared with BQ25121AYFPR and BQ25120AYFPR, the BQ25122YFPR offers the lowest default SYS voltage (1.2 V) for ultra-low-power subsystems, retains the watchdog, and maintains identical pin compatibility-making it optimal for next-gen hearables prioritizing minimal active current.

Availability

BQ25122YFPR is available at Aetrix Electronics and suitable for hearing aids, smart watches, and medical wearables requiring stable component supply, long-term lifecycle support, and certified safety compliance.

Supply support for BQ25122YFPR 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 and embedded processing technologies, with leadership in power management ICs for portable electronics.

The BQ25122YFPR belongs to TI's BQ251xx family of highly integrated charge management ICs designed specifically for space- and power-constrained wearables, hearables, and IoT edge nodes.

FAQ

What is the minimum termination current supported by the BQ25122YFPR?

The BQ25122YFPR supports a minimum termination current of 500 µA, programmable via the IPRETERM pin or I²C interface. This low threshold enables precise end-of-charge detection for small-capacity batteries used in hearing aids and earbuds, preventing overcharge and maximizing cycle life. The BQ25122YFPR achieves this using resistor-based scaling or direct register writes, with ±10% accuracy across temperature.

How does the BQ25122YFPR achieve ultra-low quiescent current in ship mode?

The BQ25122YFPR achieves <150-nA ship mode quiescent current by disabling internal regulators and disconnecting battery paths through controlled gate drive, activated via MR or CD pin assertion. This state minimizes leakage across all internal FETs and logic blocks. The BQ25122YFPR maintains this ultra-low drain even with BAT present and VIN absent, enabling multi-year shelf life without battery replacement.

Does the BQ25122YFPR support JEITA-compliant battery temperature monitoring?

Yes, the BQ25122YFPR supports JEITA-compliant battery temperature monitoring via its dedicated TS pin, which interfaces with an NTC thermistor divider to detect HOT, WARM, COOL, and COLD thresholds. These thresholds trigger automatic charge parameter adjustments to prevent charging outside safe thermal ranges. The BQ25122YFPR reports TS faults over I²C and includes 50-ms deglitching to reject noise-induced false triggers.

What is the function of the MR pin on the BQ25122YFPR?

The MR pin on the BQ25122YFPR serves as a manual reset input with three programmable functions: wake-up timer (tWAKE1/tWAKE2), system reset (tRESET), and ship mode exit. Holding MR low for >tWAKE1 or >tWAKE2 generates I²C interrupts; holding >tRESET asserts the open-drain RESET output for 400 ms. The BQ25122YFPR uses internal pull-up and configurable timing registers to eliminate external RC networks.

Can the BQ25122YFPR operate without an external microcontroller?

Yes, the BQ25122YFPR can operate autonomously using pin-strapped configurations: ISET, ILIM, IPRETERM, and LSCTRL resistors set charge current, input limit, termination, and load switch state at power-up. Default values (e.g., 1.2-V SYS, load switch enabled) allow full functionality without I²C. However, advanced features like JEITA control, dynamic voltage adjustment, and fault logging require host MCU interaction via the BQ25122YFPR's I²C interface.