Charger chip cuts component counts

A highly integrated single-cell lithium-ion/polymer battery charger IC reduces component count in a wide range of portable, battery-powered consumer applications.

AnalogicTech has introduced a highly integrated single-cell lithium-ion/polymer battery charger IC.

By bringing together a charging device, reverse blocking diode, and current sensing circuit in a small 3 x 3mm TDFN package, the device reduces component count in a wide range of portable, battery-powered consumer applications.

The AAT3687 BatteryManager also features an active thermal management system that regulates fast charge while maintaining a constant current for all ambient temperatures and input/output voltage conditions.

In today's extremely competitive portable consumer products market, higher component counts translate directly into more PCB area and can quickly kill a new product.

By integrating these primary charging functions into a single compact package and requiring a minimum number of external components, the AAT3687 helps free up valuable board space.

The battery charger supports charging currents up to 1.5A across an input voltage range of 4.0 to 5.5V.

An innovative active thermal loop charge reduction circuit reduces charging time by allowing the charger to operate at whatever rate is accessible up to 1.5A.

If the charging rate exceeds thermal restrictions, the function automatically adjusts the charger to a lower current, rather than turning the charger off, until sufficient heat is dissipated.

Multiple built-in intelligent functions maximise charging efficiency and protect the integrity of the charging device, the control system, and the battery under charge.

The device constantly monitors battery temperature and charge state to detect fault conditions.

If an overvoltage or overtemperature failure occurs, the AAT3687 automatically shuts down.

Status monitor pins indicate battery charge states by directly driving two external LEDs.

The device can also report up to twelve different charging status states to a microcontroller through an embedded serial interface.

AnalogicTech's AAT3687 also features an adapter present indicator, automatic recharge sequencing, and full battery charge turn-off or sleep mode.

Sleep mode current is very low - 2uA typical - extending system standby time.

Soft-start circuitry prevents excessive inrush current during startup.

Samples of the AAT3687 are available immediately.

The device comes in a Pb-free, thermally enhanced, 12-pin TDFN 3 x 3mm package and is rated over the -40 to +85C range.

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