Texas Instruments BQ28Z560DRZT

Overview

BQ28Z560DRZT from Texas Instruments is a single-cell Li-ion battery gas gauge IC with integrated protection and SHA-1/HMAC authentication. It performs real-time state-of-charge (%), run-time-to-empty (min), charge-time-to-full (min), voltage (V), and temperature (°C) reporting using Impedance Track™ algorithm, while controlling low-side N-channel FETs for overvoltage, overcurrent, short-circuit, and over-discharge protection in portable battery packs.

For engineers reviewing the BQ28Z560DRZT datasheet, BQ28Z560DRZT pinout, BQ28Z560DRZT application, or BQ28Z560DRZT equivalent, this device supports I²C or HDQ single-wire host communication, delivers 14–15-bit ADC resolution for coulomb counting and voltage/temperature sensing, operates from –40°C to +85°C, and integrates a 2.5-V LDO regulator with 16 mA output capability - critical for compact, secure, and reliable battery management in space-constrained consumer electronics.

Technical Context

The BQ28Z560DRZT implements a dual-oscillator architecture: a 2.097 MHz high-frequency oscillator for system timing and a 32.768 kHz low-frequency oscillator for accurate timekeeping and sleep-mode operation. Its analog front end includes a delta-sigma integrating ADC with 14–15-bit resolution for SRP/SRN differential current sensing (±0.125 V input range) and separate 14–15-bit ADCs for BAT (cell voltage) and TS (thermistor) inputs.

Protection logic executes autonomous decisions based on configurable thresholds: overcharge detection at 4.25 V (±25 mV), over-discharge at 2.30 V (±80 mV), short-circuit detection with 200–800 µs response, and overcurrent detection at ±0.15 V across sense resistor - all with programmable delay times and release conditions. Firmware control of DOUT/COUT enables dynamic discharge/charge FET management via host MCU.

Key Specifications

Pinout & Package

12-pin, 2.5-mm × 4.0-mm SON package with exposed thermal pad (Pin 13, PWPD) connected to VSS for enhanced thermal dissipation in battery pack assemblies.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ28Z560DRZT, the BQ28Z610DRZT adds USB-C power delivery readiness but increases complexity and cost, while the BQ27427YZFT reduces size and sleep current at the expense of autonomous protection - making BQ28Z560DRZT the optimal balance of integration, security, and thermal robustness for mainstream portable Li-ion packs.

Availability

BQ28Z560DRZT is available at Aetrix Electronics and suitable for tablet PCs, digital still cameras, handheld terminals, and MP3/multimedia players requiring stable component supply, long-term lifecycle support, and traceable sourcing for production programs.

Supply support for BQ28Z560DRZT 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 technologies with decades of battery management IP development.

The BQ28Z560DRZT belongs to TI's Impedance Track™ gas gauge product line, designed specifically for secure, high-accuracy single-cell Li-ion battery monitoring and autonomous protection in consumer and industrial portable equipment.

FAQ

What communication interfaces does the BQ28Z560DRZT support?

The BQ28Z560DRZT supports two host communication options: standard I²C (SMBus-compatible, 100 kHz) and HDQ single-wire interface. I²C uses dedicated SDA and SCL pins with open-drain configuration and external pull-ups; HDQ operates bidirectionally on the GPIO pin, reducing interconnect complexity. Both interfaces enable full register access, data flash read/write, and command execution for the BQ28Z560DRZT - selection depends on host MCU capabilities and board layout constraints.

How does the BQ28Z560DRZT implement battery protection without external components?

The BQ28Z560DRZT integrates autonomous protection logic with dedicated outputs: COUT drives the charge FET gate to halt charging during overvoltage (4.25 V), and DOUT controls the discharge FET to interrupt load current during over-discharge (2.30 V), short-circuit (<800 µs response), or overcurrent. It monitors VM for pack-level faults and SRP/SRN for precise current sensing - no external comparators or timers are needed. The BQ28Z560DRZT executes these actions independently of host firmware, ensuring fail-safe behavior even if the system MCU is unresponsive.

What is the role of the VREG pin on the BQ28Z560DRZT?

The VREG pin on the BQ28Z560DRZT is a 2.5-V linear regulator output capable of delivering up to 16 mA. It powers external circuitry such as thermistor bias networks, level shifters for I²C, or small signal conditioning components - eliminating the need for a separate LDO. A 0.1-µF ceramic capacitor must be placed between VREG and VSS for stability. The BQ28Z560DRZT regulates VREG from the main battery supply (BAT), maintaining accuracy across the 2.45–5.5 V input range with ±50 mV load regulation.

Can the BQ28Z560DRZT operate without an external thermistor?

Yes, the BQ28Z560DRZT can operate without an external thermistor by enabling its internal die temperature sensor via the [TEMPS] bit in Pack Configuration. While the internal sensor provides adequate thermal monitoring for basic protection (e.g., overtemperature cutoff), it lacks the spatial accuracy and thermal coupling of an external NTC on the cell tab. For JEITA-compliant charging or precise gas gauging under varying ambient conditions, the TS pin with a 10-kΩ NTC (e.g., Semitec 103AT) is required - the BQ28Z560DRZT supports both modes seamlessly.

What authentication method does the BQ28Z560DRZT use, and how is it implemented?

The BQ28Z560DRZT implements SHA-1/HMAC authentication using a secret key stored in one-time-programmable (OTP) memory. During authentication, the host MCU sends a random challenge; the BQ28Z560DRZT computes HMAC-SHA1 over the challenge and secret key, returning the 160-bit signature. The host validates the response to confirm pack authenticity. This prevents unauthorized battery substitution and ensures only certified packs engage with the charging system - a core security feature of the BQ28Z560DRZT.