WM8310GEB/V Wolfson Microelectronics, WM8310GEB/V Datasheet - Page 65

• Manufacturer Part Number: WM8310GEB/V
• Description: POWER MANAGEMENT SUBSYSTEM, 169BGA
• Manufacturer: Wolfson Microelectronics

Specifications of WM8310GEB/V

• Supply Voltage: 7V
• No. Of Step-down Dc - Dc Converters: 4
• No. Of Ldo Regulators: 11
• Digital Ic Case Style: BGA
• No. Of Pins: 169
• No. Of Regulated Outputs: 13
• Operating Temperature Range: -40°C To
• Rohs Compliant: Yes
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Pre-Production
15 POWER MANAGEMENT
15.1 GENERAL DESCRIPTION
15.2 DC-DC CONVERTER AND LDO REGULATOR CONTROL
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The WM8310 provides 4 DC-DC Converters and 11 LDO Regulators. The DC-DC Converters
comprise 3 step-down (Buck) converters and 1 step-up (Boost) converter. 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 WM8310; 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.
The WM8310 can execute programmable sequences of enabling and disabling the DC-DC Buck
Converters and LDO Regulators as part of the transitions between the ON, OFF and SLEEP power
states. The WM8310 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 WM8310 at start-up. See Section 14 for details of the OTP memory.
The integrated DC-DC Converters and LDO Regulators can each be enabled in the ON or SLEEP
power states by setting the DCm_ENA or LDOn_ENA bits as defined in Section 15.12.1. Note that
setting the DCm_ENA or LDOn_ENA bits in the OFF state will not enable the DC-DC Converters or
LDO Regulators. These bits should not be written to when the WM8310 is in the OFF state; writing to
these bits in the OFF state may cause a malfunction.
In many applications, there will be no need to write to the DCm_ENA or LDOn_ENA bits, as these
bits are controlled by the WM8310 when a power state transition is scheduled. Dynamic, run-time
control of the DC-DC Converters or LDOs is also possible by writing to these registers. Note that the
DC-DC4 Boost Converter cannot be configured as part of the power state transitions; this Converter
must always be enabled by writing to the DC4_ENA bit.
The DC-DC Converters and LDO Regulators can be assigned to a Hardware Enable (GPIO) input for
external enable/disable control. In this case, the Converter or Regulator is not affected by the
associated DCm_ENA or LDOn_ENA bits. See Section 15.3 for further details.
The WM8310 can also control other circuits, including external DC-DC Converters or LDO
Regulators using the External Power Enable (EPE) outputs. The External Power Enable outputs are
alternate functions supported via GPIO - see Section 21. The External Power Enable outputs can be
controlled in the same way as the internal DC-DC Converters and LDO Regulators. The associated
control bits are EPE1_ENA and EPE2_ENA, as defined in Section 15.12.1.
LDO Regulator 11 is a Low Power LDO Regulator, which is configured differently to the other LDOs.
It is a low-power LDO intended for “Always-On” functions external to the WM8310 and can be
enabled when the WM8310 is in the OFF power state.
When LDO11_FRCENA is set, then LDO11 is enabled at all times in the OFF, ON and SLEEP
states. Note that LDO11 is always disabled in the BACKUP and NO POWER states. See
Section 15.12.4 for the definition of LDO11_FRCENA.
The current commanded state of each of the DC-DC Converters, LDO Regulators and EPE outputs
is indicated in the DCm_STS, LDOn_STS and EPEn_STS register bits.
If a fault condition causes any Converter or Regulator to be disabled, then the associated _ENA and
_STS fields are reset to 0.
PP, December 2009, Rev 3.0
WM8310
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