Texas Instruments BQ24170RGYT

Overview

BQ24170RGYT from Texas Instruments is a synchronous switched-mode Li-ion/Li-polymer battery charger IC with integrated 4-A N-MOSFETs, power path management, and dynamic power management (DPM). It supports 1–3-cell configurations (4.2 V/cell), operates from 4.5 V to 17 V input, delivers up to 94% efficiency, and regulates charge voltage to ±0.5% accuracy - used in tablet PCs and portable medical diagnostics equipment.

For engineers reviewing the BQ24170RGYT datasheet, BQ24170RGYT pinout, BQ24170RGYT application, or BQ24170RGYT equivalent, key selection considerations include its 1.6-MHz switching frequency, thermal regulation at 120°C, ±4% input current regulation, programmable safety timer, and compatibility with 5.5 mm × 3.5 mm VQFN-24 packaging for space-constrained portable designs.

Technical Context

The BQ24170RGYT implements a constant-frequency synchronous PWM controller with cycle-by-cycle current limiting, integrated bootstrap diode, and internal digital soft start. Its dual-path power management uses ACDRV/CMSRC to drive input NMOS pair (Q1/Q2) and BATDRV to control battery PMOS (Q3), enabling automatic adapter-to-battery switchover with break-before-make logic.

It features dedicated analog comparators for input overvoltage (OVPSET), battery thermistor qualification (TS), recharge (VRECHG), and battery short detection (VBATSHT), plus independent regulation loops for charge voltage (±0.5%), charge current (±4%), and input current (±4%) - all referenced to a stable 3.3-V internal VREF.

Key Specifications

Pinout & Package

VQFN-24 package with 5.5 mm × 3.5 mm body size and exposed thermal pad (Pin 24) requiring star-connected vias to AGND for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ24172RGYT, BQ24170RGYT offers simpler configuration for standard Li-ion but lacks voltage flexibility; versus BQ24133RHLR, it provides higher current, DPM, and comprehensive safety monitoring - making it the preferred choice for robust 4-A portable power systems.

Availability

BQ24170RGYT is available at Aetrix Electronics and suitable for tablet PCs, portable medical diagnostics equipment, and portable data capture terminals requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for BQ24170RGYT 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 leadership in battery management ICs since 2005.

The BQ24170RGYT belongs to TI's bq2417x family of highly integrated standalone Li-ion chargers designed for portable industrial and medical devices needing high-efficiency power path management and JEITA-compliant thermal safety.

FAQ

What is the maximum supported battery configuration for the BQ24170RGYT?

The BQ24170RGYT supports 1-, 2-, or 3-cell Li-ion or Li-polymer batteries with fixed 4.2 V per cell. Cell count is selected via the CELL pin: LOW for 1-cell (4.2 V), floating for 2-cell (8.4 V), and HIGH for 3-cell (12.6 V). It does not support adjustable charge voltage - that function is reserved for the BQ24172RGYT variant. The BQ24170RGYT's internal regulation ensures ±0.5% accuracy across all three configurations.

How does the BQ24170RGYT implement Dynamic Power Management (DPM)?

The BQ24170RGYT monitors input current via the ACP/ACN pins and reduces charge current in real time when the adapter approaches its current limit - preventing system brownout and maintaining stable operation. This is achieved through an internal DPM loop that prioritizes system load over battery charging. The BQ24170RGYT uses the ACSET pin to set the input current threshold, with a sensitivity of 5 A/V and ±4% regulation accuracy. No external microcontroller is required.

Can the BQ24170RGYT be used without a thermistor?

Yes, the BQ24170RGYT can operate without a thermistor by leaving the TS pin unconnected or tying it to AGND, which disables battery temperature qualification and allows charging across the full operating temperature range (–40°C to +85°C). However, this bypasses JEITA compliance and hot/cold charge suspend - a safety requirement for medical and consumer devices. For certified applications, a 103AT NTC thermistor is recommended and configured via resistor dividers on the TS pin.

What is the purpose of the TTC pin on the BQ24170RGYT?

The TTC pin on the BQ24170RGYT sets the fast-charge safety timer duration using an external capacitor (5.6 min/nF), with a programmable range of 1–10 hours. It also controls precharge termination and enables/disables timer functions: pulling TTC LOW disables both timers, while pulling it HIGH disables only the safety timer but retains charge termination. This pin ensures fail-safe charging - critical for preventing thermal runaway in the BQ24170RGYT's high-current operation.

Does the BQ24170RGYT support automatic recharge after battery voltage drops?

Yes, the BQ24170RGYT automatically restarts charging when the battery voltage falls below the recharge threshold (VRECHG), which is 100 mV below the regulated charge voltage for 1-cell, 200 mV for 2-cell, and 300 mV for 3-cell configurations. This behavior is inherent to the BQ24170RGYT's analog control architecture and requires no firmware or host intervention. Recharge qualification includes a 10-ms deglitch and 250-ms hold-off to prevent false triggering during transient load dips.