WM8310GEB/V Wolfson Microelectronics, WM8310GEB/V Datasheet - Page 118

• 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
18 AUXILIARY ADC
18.1 GENERAL DESCRIPTION
18.2 AUXADC CONTROL
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The WM8310 incorporates a 12-bit Auxiliary ADC (AUXADC). This can be used to perform a number
of system measurements (including supply voltages and battery temperature) and can also be used
to measure analogue voltages from external sources and sensors.
External inputs to the AUXADC should be connected to the pins AUXADCIN1, AUXADCIN2,
AUXADCIN3 and AUXADCIN4. The maximum voltage that can be measured is determined by the
power domain associated with each (see Section 3). In the case of AUXADCIN 1-3, the maximum
voltage is SYSVDD; in the case of AUXADCIN4, the maximum voltage is DBVDD3. Note that
SYSVDD varies according to the voltage of the preferred power source (WALLVDD, USBVDD or
BATTVDD).
The AUXADC can also measure the voltage on WALLVDD, USBVDD and BATTVDD. Internal
resistor dividers enable voltages higher than SYSVDD to be measured by the AUXADC - voltages up
to 6V can be measured on these pins.
The AUXADC is enabled by setting the AUX_ENA register bit. By default, the AUXADC is not
enabled in the SLEEP state, but this can be selected using the AUX_SLPENA field.
The AUXADC measurements can be initiated manually or automatically. For automatic operation, the
AUX_RATE register is set according to the required conversion rate, and conversions are enabled by
setting the AUX_CVT_ENA bit. For manual operation, the AUX_RATE register is set to 00h, and
each manual conversion is initiated by setting the AUX_CVT_ENA bit. In manual mode, the
AUX_CVT_ENA bit is reset by the WM8310 at the end of each conversion.
The AUXADC has 11 available input sources. Each of these inputs is enabled by setting the
respective bit in the AuxADC Source Register (R16431).
For each AUXADC measurement event (in Manual or Automatic modes), the WM8310 selects the
next enabled input source. Any number of inputs may be selected simultaneously; the AUXADC will
measure each one in turn. Note that only a single AUXADC measurement is made on any Manual or
Automatic trigger.
For example, if the AUX1, BATT and USB voltages are enabled for AUXADC measurement, then
AUX1 would be measured in the first instance, and BATT then USB would be measured on the next
manual or automatic AUXADC triggers. In this case, a total of three manual or automatic AUXADC
triggers would be required to measure all of the selected inputs.
The control fields associated with initiating AUXADC measurements are defined in Table 66.
R16430
(402Eh)
AuxADC
Control
ADDRESS
BIT
15
14
12
AUX_ENA
AUX_CVT_ENA
AUX_SLPENA
LABEL
DEFAULT
0
0
0
AUXADC Enable
0 = Disabled
1 = Enabled
Note - this bit is reset to 0 when the OFF
power state is entered.
AUXADC Conversion Enable
0 = Disabled
1 = Enabled
In automatic mode, conversions are
enabled by setting this bit.
In manual mode (AUX_RATE = 0),
setting this bit will initiate a conversion;
the bit is reset at the end of the
conversion.
AUXADC SLEEP Enable
0 = Disabled
1 = Controlled by AUX_ENA
PP, December 2009, Rev 3.0
DESCRIPTION
Pre-Production
118