Texas Instruments BQ24204DGN

Overview

BQ24204DGN from Texas Instruments is a single-chip Li-ion/Li-polymer linear charge management IC for current-limited applications, featuring 4.1 V fixed regulation voltage, integrated 500 mA powerFET, 0.5% voltage accuracy, battery insertion/removal detection, and charge termination by minimum current (1.1 mA typ) and safety timer (12.386 sec typ). It targets space-constrained portable devices powered by wall adapters with limited current capability.

For engineers reviewing the BQ24204DGN datasheet, BQ24204DGN pinout, BQ24204DGN application, or BQ24204DGN equivalent, key selection considerations include its lack of temperature sensing (TS pin not connected), absence of STAT output (no charge status indication), fixed 4.1 V regulation, and compatibility with coke- or graphite-anode single-cell batteries in low-dropout charger designs.

Technical Context

The BQ24204DGN implements a linear charging architecture using an internal P-channel powerFET to regulate battery voltage via BAT-pin feedback. It relies on an external current-limited input supply-no internal current regulation-and uses a precision voltage reference (±0.5% over –40°C to 125°C) to maintain 4.1 V regulation during constant-voltage phase.

Charge control includes pre-conditioning (13.5 mA typ) for deeply discharged cells below 2.95 V, taper-current detection (25.5 mA typ), and dual termination criteria: minimum current (1.1 mA typ) and fixed charge timer (12.386 sec typ). Sleep mode activates when VCC falls below battery voltage minus 10 mV, reducing quiescent current to 10 µA.

Key Specifications

Pinout & Package

Package: 8-pin MSOP-PowerPAD (DGN), thermally enhanced with exposed die pad for PCB heat dissipation; RoHS-compliant, CU NIPDAU finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Li-ion linear charge management applications.

Compared with BQ24204DGN, BQ24203DGN adds charge status signaling at minor cost and pin count increase, while BQ24205DGN offers identical functionality under alternate TI part numbering-making BQ24204DGN optimal for cost- and space-sensitive designs where status reporting is omitted.

Availability

BQ24204DGN is available at Aetrix Electronics and suitable for wireless headsets, medical sensors, and industrial handhelds requiring stable component supply, long-term production continuity, and RoHS-compliant packaging.

Supply support for BQ24204DGN 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 delivering analog and embedded processing solutions, with leadership in power management ICs and battery charging technology.

The BQ24204DGN belongs to the bq2420x family of single-cell Li-ion linear chargers designed for cost-sensitive, space-constrained portable electronics using current-limited wall adapters - prioritizing integration, reliability, and ease of layout over programmability.

FAQ

What is the regulation voltage of the BQ24204DGN?

The BQ24204DGN has a fixed regulation voltage of 4.1 V with ±0.5% accuracy over –40°C to 125°C. This value is factory-trimmed and non-adjustable, optimized for graphite-anode Li-ion cells. The BQ24204DGN achieves this using an internal bandgap reference and precision feedback amplifier tied to the BAT pin, ensuring stable termination without external resistor networks.

Does the BQ24204DGN support temperature monitoring?

No, the BQ24204DGN does not support temperature monitoring. Per TI's device marking table (AZG), the TS pin is not connected internally. Unlike BQ24200/BQ24201, this variant omits the temperature comparator circuitry entirely. Thermal protection relies solely on the IC's internal thermal shutdown and external system-level design - no thermistor interface or voltage thresholds are active on the BQ24204DGN.

What is the purpose of the CE pin on the BQ24204DGN?

The CE (Charge Enable) pin on the BQ24204DGN is an active-low digital input that controls charge initiation and suspension. When pulled low, it enables charging and starts timers; when high, it disables the internal powerFET and resets all charge timers. This allows host MCU or system logic to manage charging sequences deterministically - critical for power-aware systems where charging must align with usage states or firmware updates.

Can the BQ24204DGN be used with a 5 V wall adapter?

Yes, the BQ24204DGN is compatible with standard 5 V wall adapters, provided the adapter is current-limited to ≤500 mA. Its 350 mV typical dropout voltage at full load means it can regulate 4.1 V output even with input as low as 4.45 V. However, because the BQ24204DGN lacks internal current regulation, the adapter itself must enforce current limiting - otherwise, excessive power dissipation may trigger thermal shutdown or damage the IC.

What happens when the battery voltage drops after full charge on the BQ24204DGN?

After charge termination, the BQ24204DGN automatically resumes charging when the battery voltage falls to the recharge threshold VRCH = VO(REG) – 0.085 V (≈4.015 V). This hysteresis prevents rapid cycling and maintains the battery near full capacity. Recharge is initiated without external intervention and follows the same pre-charge → constant-current → constant-voltage → taper-termination sequence as initial charge.