WM8311GEB/V Wolfson Microelectronics, WM8311GEB/V Datasheet - Page 100

• Manufacturer Part Number: WM8311GEB/V
• Description: POWER MANAGEMENT SUBSYSTEM, 121BGA
• Manufacturer: Wolfson Microelectronics

Specifications of WM8311GEB/V

• Supply Voltage: 5.5V
• No. Of Step-down Dc - Dc Converters: 4
• No. Of Ldo Regulators: 7
• Digital Ic Case Style: BGA
• No. Of Pins: 121
• No. Of Regulated Outputs: 9
• Operating Temperature Range: -40°C To
• Rohs Compliant: Yes
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

WM8311
17 POWER SUPPLY CONTROL
17.1 GENERAL DESCRIPTION
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The WM8311 can take its power supply from a Wall adaptor, a USB interface or from a single-cell
lithium battery. The WM8311 autonomously chooses the most appropriate power source available,
and supports hot-swapping between sources (ie. the system can remain in operation while different
sources are connected and disconnected).
Comparators within the WM8311 identify which power supplies are available and select the power
source in the following order of preference:
•
•
•
Note that the Wall supply is normally the first choice of supply, provided that it is within the operating
limits quoted in Section 6. The WM8311 can operate with any combination of these power supplies,
or with just a single supply.
When WALLVDD or USBVDD is selected as the power source, this may be used to charge the
Battery, using the integrated battery charger circuit.
The recommended connections between the WM8311 and the WALL, USB and Battery supplies are
illustrated in Figure 24. Note that the external FET components may be omitted in some applications,
as described later in this section.
Figure 24 WM8311 Power Supply Connections
SYSVDD is primarily an output from the WM8311; this output is the preferred supply, where the
WM8311 has arbitrated between the Wall, Battery and USB connections. This output is suitable for
supplying power to the other blocks of the WM8311, including the DC-DC Converters and LDO
Regulators. SYSVDD is also an input under some conditions, such as battery charging from the Wall
supply. The voltage at the SYSVDD load connection point is sensed using the SYSVMON pin.
All loads connected to the WM8311 should be connected to the SYSVDD pin. The inputs to the DC-
DC Converters and LDOs are typically connected to the SYSVDD pin. The inputs to the LDOs may,
alternatively, be connected to the outputs of the DC-DCs if desired.
Wall adaptor (WALLVDD)
USB power rail (USBVDD)
Battery (BATTVDD)
PP, December 2009, Rev 3.0
Pre-Production
100