SMB136 and SMB137B battery chargers

Summit Microelectronics has introduced two more members of its programmable battery charger integrated circuit family.

The SMB136 and SMB137B use CurrentPath technology, providing dual input source (USB or AC/DC) with arbitration, dual output for system and battery and system operation with a dead or missing battery.

Both support all battery charging standards: USB 2.0 specification, USB on-the-go supplement, USB battery charging specification 1.0, IEEE1725 standard, Chinese USB charging specification and others.

Furthermore, the devices are the only battery charger ICs with CurrentPath to detect the input source type (USB host/hub, AC/DC, etc) and automatically optimise operation for the fastest and safest charging.

The chargers are based on a 3 MHz, switchmode architecture, with minimal external components, allowing efficient power delivery and compact size. High-efficiency operation enables fast charging due to higher output/charge currents, while reduced thermal dissipation improves user comfort, system reliability and green operation.

TurboCharge enables high charge current, even from relatively low-power sources (example: up to 750 mA output from 500 mA USB source).

The SMB136 features one power input (USBIN) that allows USB500/100 or AC/DC (700-1400 mA) operation.

The SMB137B features two power inputs, one for supporting AC/DC power sources and the second one for supporting USB power sources. Both provide independent output current paths for the system and the battery, allowing the system to turn on with a missing or deeply discharged battery.

Both devices have low-battery recovery mode, which provides two benefits - it enables booting up from a USB1 source and a dead battery (common scenario for smart phones and media players) and it extends battery run time for emergency operation.

This is accomplished by running the battery charger in reverse (boost) and providing the system with 4.17 V at up to 500 mA. This technology also eliminates the need for buck/boost regulators in systems with extended voltage range Li+ batteries (less than 3.0 V).