DESCRIPTION

WM8311 is an integrated power-management subsystem which provides a cost-effective, flexible, single-chip solution for power management, specifically targeted at the requirements of a range of low-power portable applications. WM8311 is specifically designed to operate as a system PMIC supporting a variety of industry standard processors and accessories in a wide range of applications.

The start-up behaviour and configuration is fully programmable in an integrated OTP non-volatile memory. This highly flexible solution helps reduce time-to-market, as changing application requirements can be very easily accommodated in the OTP contents.

The WM8311 power management subsystem comprises of four programmable DC-DC converters, seven LDO regulators (one of which is low-noise for supplying sensitive analogue subsystems). The integrated OTP bootstrap circuitry controls the start-up sequencing and voltages of the converters and regulators as well as the sequencing of system clocks.

WM8311 can be powered from a battery, a wall adaptor or from a USB power source. An on-chip regulator provides power for always-on PMIC functions such as register map and the RTC. The device provides autonomous backup battery switchover. A low-power LDO is included to support ‘Alive' processor power domains external to the WM8311.

A linear on-chip battery charger supports trickle charging and constant current / constant voltage charging of single-cell lithium-ion / lithium-polymer batteries. The charge current, termination voltage, and charger time-out are programmable. WM8311 detects and handles battery fault conditions with a minimum of system software involvement.

A 12-bit Auxiliary ADC supports a wide range of applications for internal as well as external analogue sampling, such as voltage detection and temperature measurement. The Touch Panel controller uses the same ADC on an interleaved basis.

WM8311 includes a crystal oscillator, an internal RC oscillator and Frequency Locked Loop (FLL) to generate all clock signals for autonomous system start-up and processor clocking. A Secure Real time Clock (S-RTC) and alarm function is included, capable of waking up the system from low-power modes. A watchdog function is provided to ensure system integrity.

To maximise battery life, highly-granular power management enables each function in the WM8311 subsystem to be independently powered down through a control interface or alternatively through register and OTP-configurable GPIOs. The device offers a standby power consumption of <10uA, making it particularly suitable for portable applications.

The WM8311 is supplied in a 8x8mm 121-ball BGA package, ideal for use in portable systems. The WM8311 forms part of the Wolfson series of audio and power management solutions.