Skyworks Solutions Inc. AAT3670ISK-4.2-T1

Overview

AAT3670ISK-4.2-T1 from Skyworks Solutions is a dual-input 1.6A Li-ion battery charger and system power manager IC for single-cell 4.2V batteries. It enables simultaneous charging and full-system operation using AC adapter (up to 1.6A) or USB (up to 0.9A) inputs, with voltage-sensed charge current reduction, integrated load switches, and battery temperature monitoring. It is used in portable consumer electronics requiring robust power path management.

For engineers reviewing the AAT3670ISK-4.2-T1 datasheet, AAT3670ISK-4.2-T1 pinout, AAT3670ISK-4.2-T1 application, or AAT3670ISK-4.2-T1 equivalent, key selection criteria include ADP/USB input current limiting, programmable 4.2V charge regulation, thermal loop behavior, STATx status reporting, and QFN-24 package compatibility with board-level thermal design constraints.

Technical Context

The AAT3670ISK-4.2-T1 implements independent ADP and USB charge paths with dedicated FETs (R_DS(ON) = 0.4Ω ADP, 0.7Ω USB), plus three internal load switches (ADP→OUT, USB→OUT, BAT→OUT) with R_DS(ON) of 0.4Ω, 0.7Ω, and 0.1–0.2Ω respectively. It uses analog feedback loops for precise 4.20V ±21mV battery voltage regulation and supports programmable charge termination via external resistor on TERM.

Its dynamic power management includes voltage-sensed charge reduction (4.6V ADP / 4.5V USB thresholds), digitized thermal loop (entry at 115°C, exit at 95°C), and automatic recharge at V_{BAT_EOC} − 0.1V. Battery protection covers over-voltage (4.30–4.35V), under-voltage (2.8–3.0V UVLO), over-current, and NTC-based temperature monitoring via TS/VTS pins.

Key Specifications

Pinout & Package

The AAT3670ISK-4.2-T1 is housed in a Pb-free, thermally enhanced 24-pin QFN package (4 mm × 4 mm, 0.5 mm pitch) with an exposed thermal pad (EP) that must be soldered to PCB ground for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery charging and power path management applications.

Compared with BQ24075RGTR and MAX8903BETE+, the AAT3670ISK-4.2-T1 uniquely combines dual-input priority selection, voltage-sensed adaptive charge reduction, and integrated 0.1–0.2Ω BAT→OUT switch-enabling higher efficiency, faster recharge, and more robust system-level power continuity.

Availability

AAT3670ISK-4.2-T1 is available at Aetrix Electronics and suitable for smartphone power management, digital camera charging systems, handheld PDA architectures, and MP3 player battery interfaces requiring stable component supply, long-term lifecycle support, and consistent parametric performance.

Supply support for AAT3670ISK-4.2-T1 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

Skyworks Solutions is a global provider of analog semiconductors for wireless infrastructure, mobile devices, automotive, and IoT applications, with leadership in RF, power management, and precision timing.

The AAT3670ISK-4.2-T1 belongs to Skyworks' BatteryManager™ family, engineered specifically for space-constrained portable electronics needing concurrent battery charging and uninterrupted system operation under variable input conditions.

FAQ

What is the exact battery charge voltage regulation accuracy of the AAT3670ISK-4.2-T1?

The AAT3670ISK-4.2-T1 regulates battery voltage to 4.20 V with a tolerance of ±21 mV (4.158 V to 4.242 V) for 4.2V Li-ion cells, specified over 0°C to 70°C ambient and guaranteed across −40°C to +85°C by design. This accuracy ensures compliance with JEITA and IEC 62133 standards for safe lithium-based battery charging.

How does the AAT3670ISK-4.2-T1 handle input source priority between ADP and USB?

The AAT3670ISK-4.2-T1 automatically selects ADP over USB when both are present, due to ADP's higher available current (1.6A vs. 0.9A) and lower R_DS(ON) (0.4Ω vs. 0.7Ω). The device routes ADP to both system load (OUT) and battery simultaneously, disabling USB input until ADP is removed-ensuring optimal power utilization without firmware intervention.

Can the AAT3670ISK-4.2-T1 operate without battery temperature monitoring?

Yes-the AAT3670ISK-4.2-T1 allows temperature monitoring to be disabled by tying the TS pin directly to GND. When disabled, thermal fault protection based on NTC sensing is inactive, but digitized junction thermal loop (115°C entry, 140°C shutdown) remains fully functional to protect the IC itself during high-power operation.

What is the function of the CHRADP and CHRUSB pins on the AAT3670ISK-4.2-T1?

The CHRADP and CHRUSB pins on the AAT3670ISK-4.2-T1 configure voltage-sensed charge current reduction thresholds-4.6V for ADP and 4.5V for USB by default. When input voltage falls below these thresholds, the device proportionally reduces charge current to prevent source overload while sustaining system load, enabling stable operation even with weak or aging adapters/USB ports.

Does the AAT3670ISK-4.2-T1 support automatic recharge, and how is it triggered?

Yes-the AAT3670ISK-4.2-T1 supports automatic recharge triggered when battery voltage drops to V_{BAT_EOC} − 0.1V (e.g., 4.10V for a 4.20V termination). This threshold is fixed and temperature-compensated; recharge initiates a full CC/CV cycle, ensuring the battery remains at optimal capacity without user or host controller involvement.