Pre-Production
WM8850
APPLICATIONS INFORMATION
RECOMMENDED EXTERNAL COMPONENTS
Figure 23 Recommended External Components
Notes:
1. AC-coupling capacitors for inputs may depend on circuitry used prior to WM8850. Typical values between 1µF and
10µF are common – consult any documentation for the exact circuit used
2. AC-coupling capacitors for outputs may depend in circuitry used after WM8850. Typical values between 1µF and 10µF
are common – consult any documentation for the exact circuit used
3. A single-ended mono microphone input is shown, but other configurations are equally valid. The value of the
microphone bias resistor will vary with the microphone used – a typical value is 2.2kΩ
4. The capacitor between CFB1 and CFB2 must be placed as close as possible to the device pins
5. The decoupling capacitor on CPCAP must also be placed as close as possible to the device pins
6. The decoupling capacitor on CPVDD is next important – it too should be placed as close as possible to the device pins
7. The decoupling capacitors on VREFP, VREFN and VMID are next important, in that order
8. All remaining decoupling capacitors should then be placed as close as possible
PP, April 2011, Rev 3.2
219
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
