Features of a PMIC, General PMIC Characteristics

Intel® PXA27x Processor Family Power Requirements

	Characteristic	Description

	Highly Integrated,	Incorporating buck, boost, buck-boost, and LDO regulators for the PXA27x processor
	Multi-Function	and surrounding system elements, with dynamic voltage management (DVM) logic for
	Multi-Function	the core supply. It includes power-up, power-down, and sleep mode power sequencing,

		and generates correct nRESET, nBATT_FAULT, and nVDD_FAULT outputs for the
		system. Ideally, it also incorporates battery charger circuits and an output to notify the
		system when AC power input is present; touchscreen and audio CODECs would be a
		plus, if they can meet industry-standard noise and distortion requirements when
		combined on the same silicon.

	Low-Cost	High integration provides a packaged device that must be lower cost than the
		alternative comprised of discrete power supply devices.

	High Efficiency	Converters operate in the 85-95% efficiency range under all load conditions, and with
		very low quiescent current and shutdown currents (off or sleep mode).

	I2C Interface	Must be standard I2C interface operating at either 40 kHz standard mode or 160 kHz
		fast-mode clock rate.

	Stable and Accurate	Meets ± 3% accuracy or better at the PMIC output signals over input variation, load
		variation, and temperature for all regulators and converter outputs. Switching
		regulators must minimize noise propagated into regulator outputs.

	Reliable	Current and thermal limiting on all regulators.

8.2Features of a PMIC

The basic features of a PMIC for use with the PXA27x processor include:

•Multiple channels of regulated power output

•Dynamic voltage management (DVM) capability for the PXA27x processor core supply

•Debounced push button ON/OFF and user-reset inputs

•AC adapter detect capability

•Power-on / user reset output to the PXA27x processor nRESET input

•nBATT_FAULT signal, signifying main battery removed

•nVDD_FAULT signal, indicating any power regulator out of spec

•Automatic switch over from main battery to backup battery when main battery is discharged or removed

•Responds to the PXA27x processor mode change requests by switching regulators on or off

•Control and Status registers accessible through I2C interface

•Provides USIM power FET control to supply 3.0 V or 1.8 V to USIM card

The features of a PMIC for battery charging also include:

•Charging capability for lithium-ion or lithium-polymer main battery

•Support for either rechargeable or non-rechargeable backup battery

•Digital output battery level monitor (“fuel gauge”) for main and backup batteries (optional)

•Battery charging current and temperature monitoring, for fast charging of main battery (optional)

Application Note