Texas Instruments BQ25703ARSNR

Overview

BQ25703ARSNR from Texas Instruments is a synchronous NVDC buck-boost battery charge controller for 1–4-cell Li+, LiFePO₄, NiCd, NiMH, or lead-acid batteries, supporting 3.5 V–24 V input, ±0.5% charge voltage regulation, I²C host control, and integrated ADC for voltage/current/power monitoring.

For engineers reviewing the BQ25703ARSNR datasheet, BQ25703ARSNR pinout, BQ25703ARSNR application, or BQ25703ARSNR equivalent, this device is selected for USB PD-compatible portable systems requiring seamless buck/boost transition, PROCHOT-based CPU throttling, and system power path management with instant-on capability.

Technical Context

The BQ25703ARSNR implements a dual-phase synchronous buck-boost topology with independent high-side (HIDRV1/HIDRV2) and low-side (LODRV1/LODRV2) gate drivers, enabling automatic mode switching between buck, boost, and buck-boost based on real-time VBUS, VSYS, and battery voltage conditions without host intervention.

It integrates IMVP8-compliant PROCHOT generation using programmable thresholds for IADPT, IBAT, and PSYS, plus hardware-based input current limiting via ILIM_HIZ and software-configurable VDPM/IDPM regulation - all coordinated through a single I²C interface (address D6h) with register-mapped control of charge voltage, current, OTG output, and safety limits.

Key Specifications

Pinout & Package

Package: 32-pin 4.00 mm × 4.00 mm WQFN with exposed thermal pad (RSN package).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar buck-boost battery charge controller applications.

Compared with BQ25700ARSNR, the BQ25703ARSNR adds essential PROCHOT and IMVP8 support for CPU-integrated thermal management; versus BQ25710RGER, it trades one ADC channel and 8 extra pins for smaller footprint and lower cost in mid-power portable designs.

Availability

BQ25703ARSNR is available at Aetrix Electronics and suitable for USB PD tablet PCs, industrial handheld scanners, and portable medical monitors requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for BQ25703ARSNR 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 ICs, with decades of expertise in battery charging and system power architecture.

The BQ25703ARSNR belongs to TI's bq257xx family of NVDC buck-boost charge controllers, designed specifically for space-constrained, multi-chemistry portable devices needing intelligent power path management and CPU thermal coordination.

FAQ

What is the primary function of the BQ25703ARSNR in a portable system?

The BQ25703ARSNR serves as a synchronous NVDC buck-boost battery charge controller that manages power flow between input sources (e.g., USB PD adapters), battery (1–4S), and system rail (VSYS). It enables instant-on operation, seamless topology switching, and integrated PROCHOT-based CPU throttling - all critical for modern portable computing and medical devices. The BQ25703ARSNR replaces discrete power path solutions with a single IC delivering high accuracy and configurability.

Does the BQ25703ARSNR support USB On-The-Go (OTG) functionality?

Yes, the BQ25703ARSNR supports USB OTG by generating a regulated VBUS output from the battery, programmable from 4.48 V to 20.8 V with current limiting up to 6.35 A. OTG mode is enabled via the EN_OTG pin and I²C register REG0x35[4], and the device maintains tight voltage regulation and overcurrent protection during discharge - making the BQ25703ARSNR suitable for USB PD-compliant portable accessories and docking solutions.

How does the BQ25703ARSNR implement PROCHOT signaling for CPU thermal management?

The BQ25703ARSNR implements IMVP8-compliant PROCHOT signaling through its dedicated PROCHOT pin (Pin 11), which asserts an active-low open-drain pulse when any of three monitored conditions exceed thresholds: adapter current (IADPT), battery discharge current (IBAT), or system power (PSYS). Pulse width and trigger sensitivity are configurable via I²C registers (e.g., REG0x36), allowing precise coordination with x86/ARM CPUs - a core capability distinguishing the BQ25703ARSNR from earlier variants like BQ25700A.

What package type and pin count does the BQ25703ARSNR use?

The BQ25703ARSNR uses a 32-pin WQFN package (RSN variant) with nominal dimensions of 4.00 mm × 4.00 mm and an exposed thermal pad. This compact footprint supports high-density PCB layouts in thin-profile devices such as tablets and handheld scanners. All critical functions - including dual gate drivers, current sense inputs, I²C interface, and PROCHOT output - are mapped to these 32 pins, with no need for external level shifters or auxiliary ICs in standard implementations of the BQ25703ARSNR.

Can the BQ25703ARSNR charge different battery chemistries?

Yes, the BQ25703ARSNR supports Li+, LiFePO₄, NiCd, NiMH, and lead-acid batteries through I²C-programmable charge profiles. Parameters including charge voltage, termination current, and precharge rate are fully configurable per chemistry - for example, setting 4.2 V per cell for Li+, 3.65 V for LiFePO₄, or 2.4 V for NiMH. This flexibility allows a single BQ25703ARSNR design to serve multiple product variants without hardware changes, reducing BOM complexity and qualification effort.