Diodes Incorporated APM8600FB-7

Overview

APM8600FB-7 from Diodes Incorporated is a single-cell linear lithium-ion battery charger IC with 28V input overvoltage protection, resistor-programmable charge current up to 1A, capacitor-programmable charge timer, and integrated thermal foldback at +100°C. It implements full-charge sequencing-prequal, constant-current/constant-voltage fast-charge, and top-off-with three status outputs (CHG, POK, FLT) for system-level monitoring in compact portable devices.

For engineers reviewing the APM8600FB-7 datasheet, APM8600FB-7 pinout, APM8600FB-7 application, or APM8600FB-7 equivalent, key selection criteria include its U-DFN3030-14 thermal-pad package, 4.15–7.0V operating input range, ±0.5% battery voltage regulation at 4.2V, programmable end-of-charge threshold via SETI resistor, and fault detection via CT timer timeout or THM thermistor out-of-range conditions.

Technical Context

The APM8600FB-7 integrates a linear pass transistor with R_DS(on) = 0.5Ω (typ.), precision 4.2V ±0.5% battery regulation reference, and dual-threshold comparators for UVLO (4.0V typ.) and OVLO (7.5V typ.). Its charge control logic autonomously transitions between prequal (3.0V threshold), fast-charge (IBAT > 112.5/R_SETI), and top-off (IBAT < 7.5% of I_CHARGE) states based on real-time BAT voltage and current sensing.

Thermal management combines junction-based foldback (activation at +100°C, 5%/°C gain) with external NTC thermistor monitoring via THM pin (3.94kΩ–28.3kΩ valid range), while safety timers-prequal (34.8 min), fast-charge (334 min), and top-off (34.8 min)-are set by a single CT capacitor with ±20% accuracy.

Key Specifications

Pinout & Package

The APM8600FB-7 is housed in a U-DFN3030-14 package (3.0mm × 3.0mm × 0.55mm) with exposed thermal pad (EP) for PCB copper connection to enhance heat dissipation. Pin 1 is marked by a dot; pins are numbered counterclockwise from top-left in top view.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar single-cell linear lithium-ion charger applications.

Compared with TP4056 and BQ24075, the APM8600FB-7 uniquely balances high-input survivability (28V), precise thermal safety (dual NTC + junction foldback), and minimal external components-making it optimal for ruggedized portable equipment where input transients and battery temperature variability are design constraints.

Availability

APM8600FB-7 is available at Aetrix Electronics and suitable for handheld test equipment, digital still cameras, MP3 players, and multimedia players requiring stable component supply across production lifecycles.

Supply support for APM8600FB-7 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in power management, signal integrity, and protection solutions for consumer, industrial, and computing markets.

The APM8600 belongs to Diodes' battery management IC product line, engineered specifically for space-constrained, single-cell Li-ion applications demanding high input voltage tolerance, accurate regulation, and multi-layer thermal safety without sacrificing bill-of-materials simplicity.

FAQ

What is the maximum allowable input voltage for continuous operation?

The APM8600FB-7 operates continuously within 4.15V to 7.00V input range. While it withstands up to 28V without damage, charging is disabled above 7.5V due to internal OVLO circuitry. This 28V rating protects against transient surges from wall adapters or automotive USB sources, but sustained input must remain ≤7.0V for functional charging.

How does the THM pin determine battery temperature validity?

The THM pin reads resistance from a 10kΩ NTC thermistor placed near the battery. Valid charging occurs only when R_THM is between 3.94kΩ and 28.3kΩ (corresponding to ~0°C to ~50°C). Below 315Ω (open thermistor) or above 28.3kΩ (excessive cold), charging halts and CHG goes high-Z. No external biasing is needed-the IC provides internal pullup.

Can the charge timer be disabled, and how?

Yes, the charge timer is disabled by connecting the CT pin directly to GND. This removes all time-based safety limits (prequal, fast-charge, top-off), reverting behavior to voltage- and current-based state transitions only. For safety-critical applications, Diodes recommends retaining CT capacitor configuration per datasheet defaults (e.g., 68nF for 334-minute fast-charge limit).

What is the function of the exposed thermal pad (EP) and how should it be connected?

The exposed pad (EP) is electrically connected to GND and serves as the primary thermal conduction path. It must be soldered to a minimum 1.8mm × 2.4mm copper area on the PCB with ≥6 thermal vias (0.25mm diameter) to an internal or bottom-layer ground plane. This achieves the specified θ_JA = 40°C/W and prevents thermal shutdown during 1A continuous charging.