wm8321 Wolfson Microelectronics plc, wm8321 Datasheet - Page 3

• Manufacturer Part Number: wm8321
• Description: Processor Power Management Subsystem
• Manufacturer: Wolfson Microelectronics plc

Product Brief
TYPICAL APPLICATIONS
w
The WM8321 is designed as a system PMIC device that generates configurable DC supplies to
power processors and associated peripherals within a system. The WM8321 provides four step-down
DC-DC converters. Two of these can operate in dual mode, providing an increased current capability.
Eleven LDO regulators provide a high degree of flexibility to provide power to multiple devices, with
the capability to power-up and power-down different circuits independently.
Two of the DC-DC step-down converters are specifically designed to handle rapid changes in load
current, as required by modern application processors; selectable operating modes allow the
converters to be optimally configured for light, heavy or transient load conditions; they can also be
tailored for minimum PCB area, maximum performance, or for maximum efficiency. The analogue
LDOs provide low-noise outputs suitable for powering sensitive circuits such as RF / Wi-Fi / cellular
handset applications.
The WM8321 powers up the converters and LDOs according to a programmable sequence. A
configurable ‘SLEEP’ state is also available, providing support for an alternate configuration, typically
for low-power / standby operation. The power control sequences and many other parameters can be
stored in an integrated user-programmable OTP memory or may be loaded from an external
memory. The WM8321 supports the programming and verification of the integrated OTP memory.
A backup battery supply can be connected to the WM8321 in order to maintain the Real Time Clock
(RTC) in the absence of the primary supply. The WM8321 provides a battery charger for the backup
battery.
Programmable GPIO pins may be configured as hardware inputs for general use or for selecting
different power management configurations. As outputs, the GPIOs can provide indications of the
device status, or may be used as control signals for other power management circuits. The WM8321
also provides two LED drivers, which can be controlled manually or configured as status indicators
for the OTP memory programmer or operating power state.
Product Brief, April 2010, Rev 1.2
WM8321
3