wm8325gefl/v Wolfson Microelectronics plc, wm8325gefl/v Datasheet - Page 11

• Manufacturer Part Number: wm8325gefl/v
• Description: Processor Power Management Subsystem
• Manufacturer: Wolfson Microelectronics plc

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BUCKWISE™ TECHNOLOGY
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The WM8325 provides 4 DC-DC Converters and 11 LDO Regulators. The DC-DC Converters include
2 BuckWise™ valley-mode converters. The Regulators comprise general purpose LDOs (LDO1 -
LDO6) and low-noise analogue LDOs (LDO7 - LDO10). The analogue LDOs offer superior PSRR,
noise and load-transient performance. LDO11 is a low power LDO intended for powering “always on”
circuits connected to the WM8325; this LDO can be configured to remain enabled in the OFF state.
These power management components are designed to support application processors and
associated peripherals. DC-DC1 and DC-DC2 are intended to provide power to the processor voltage
domains; DC-DC3 is suitable for powering memory circuits or for use as a pre-regulator for the
LDOs. The output voltage of each of the buck converters and regulators is programmable in software
through control registers. DC-DC3 and DC-DC4 can be ganged together in dual mode, providing an
increased current capability for higher power processor voltage domains.
The WM8325 can execute programmable sequences of enabling and disabling the DC-DC
Converters and LDO Regulators as part of the transitions between the ON, OFF and SLEEP power
states. The WM8325 power management circuits can also interface with configurable hardware
control functions supported via GPIO pins. These include GPIO inputs for selecting alternate
voltages or operating modes, and GPIO outputs for controlling external power management circuits.
The configuration of the power management circuits, together with some of the GPIO pins and other
functions, may be stored in the integrated OTP memory. This avoids any dependence on a host
processor to configure the WM8325 at start-up.
The BuckWise™ converter is the first Valley mode DC-DC converter integrated into a system PMIC.
This technology has several key benefits:
The BuckWise™ load transient performance is illustrated in Figure 1.
Market leading transient performance
Valley Mode Control (VMC)
>90% efficiency
Multiple modes of operation
Dynamic Voltage Scaling (DVS) control
with a single register write or via hardwired
GPIO pin.
FEATURE
Able to use smaller capacitors to meet processor
transient requirements.
Processors are able to operate at lower voltages
(saving power) without hitting minimum voltage
specifications.
Ensures there is no performance degradation at low
output voltages (0.6V).
Will support next-generation processors (<45nm)
with low voltage requirements.
Longer battery life in portable devices.
Maintains high efficiency across the full load range,
increasing battery life.
Allows the regulator to slew from one output voltage
to another with a programmable slew rate.
Enables processor to switch seamlessly between
power modes for optimum processor performance at
the lowest possible power.
Product Brief, February 2011, Rev 1.4
BENEFITS
WM8325
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