WM8310GEB/V Wolfson Microelectronics, WM8310GEB/V Datasheet - Page 160

• 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

WM8310
27 VOLTAGE AND CURRENT REFERENCES
27.1 VOLTAGE REFERENCE (VREF)
27.2 CURRENT REFERENCE (IREF)
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The main voltage reference generated by the WM8310 is bonded to the VREFC pin. The accuracy of
this reference is optimised by factory-set trim registers.
The voltage reference (VREF) requires an external decoupling capacitor; a 100nF X5R capacitor is
recommended, as noted in Section 30.2. Omitting this capacitor will result in increased noise on the
voltage reference; this will particularly affect the analogue LDOs.
The VREFC capacitor should be grounded to the REFGND pin.
The voltage reference circuit includes a low-power mode, which enables power consumption to be
minimised where appropriate. The low-power reference mode may lead to increased noise on the
voltage reference; this mode should only be selected when minimum power consumption is more
important than voltage stability. Note that the Low Power Reference mode is not supported when the
Auxiliary ADC function is enabled.
The Low Power Reference mode is enabled when REF_LP register is set. The Low Power Reference
mode should only be enabled when the Auxiliary ADC is disabled. Enabling the Low Power
Reference mode will lead to a malfunction of the Auxiliary ADC function.
R16387
(4003h)
Table 107 Low Power Voltage Reference Control
The Power Management circuits of the WM8310 use an integrated current reference.
This current reference (IREF) requires the connection of an external resistor to the IREFR pin; a
100kΩ (1%) resistor is recommended, as noted in Section 30.2. The WM8310 will malfunction if this
resistor is omitted.
The IREFR resistor should be grounded to the REFGND pin.
ADDRESS
BIT
12
REF_LP
LABEL
DEFAULT
0
Low Power Voltage Reference Control
0 = Normal
1 = Low Power Reference Mode select
Note that Low Power Reference Mode is
only supported when the Auxiliary ADC is
disabled.
DESCRIPTION
PP, December 2009, Rev 3.0
Pre-Production
160