Configurable PMIC has all the power regulation you need for Li-ion battery-power

September 15, 2014 // By Graham Prophet
ams’ AS3715is a configurable power management IC (PMIC) which enables OEMs to implement power circuits for multiple end products with the same hardware design. The AS3715’s features are suited to action cameras and portable navigation devices.

The IC includes all the essential power management building blocks required to provide a power solution for handheld devices powered by lithium-ion batteries, such as action cameras, navigation devices, tablets, media players and gaming consoles.

It offers the capability to program the start-up configuration, so that the operation of the power system can be adapted for different application processors. The programmability of the start-up sequence and of the built-in DC-DC converters' outputs allows design teams to accommodate changes in end-product specifications at any time without re-spinning their board design.

The power regulation blocks in the AS3715 include:

• three 4 MHz DC-DC step-down (buck) converters with programmable outputs

• one DC-DC step-down controller

• two DC-DC step-up (boost) converters with programmable outputs

• eight LDOs

The device also offers eight GPIOs, a charger circuit supporting a 1.5A output, an I²C interface, three current sinks, an ADC and a watchdog timer.

The DC-DC controller controls external power stages, allowing the user to maximise efficiency, simplify PCB routing and distribute power and heat dissipation over a wide board area. It supports configuration as either a single- or dual-phase controller, which means that the system’s efficiency 'sweet spot’ can be adapted to the requirements and size constraints of the design. The DC-DC controller can manage an output current of up to 8A. Two of the eight LDOs are low-noise devices suited to RF modules, image sensors and other noise-sensitive circuits.

The AS3715’s three high-voltage current sinks, which are intended for LCD backlighting, provide a programmable current output adjustable in 150 µA increments in a range from 0 to 40 mA. PWM input options provide a means to implement dynamic luminance scaling. The integrated 5V boost converter can supply power to HDMI interfaces or other 5V peripherals. Other configuration options include the ability to implement either switched-mode or linear charging, depending on whether the design must be optimised for power efficiency or for space