WM8532 Production Data
w
PD, Rev 4.2, June 2014
18
APPLICATIONS INFORMATION
RECOMMENDED EXTERNAL COMPONENTS
Figure 16 Recommended External Components
Notes:
1. Wolfson recommend using a single, common ground plane. Where this is not possible, care should be taken to
optimise split ground configuration for audio performance.
2. Charge Pump fly-back capacitor C5 should be placed as close to WM8532 as possible, followed by Charge Pump
decoupling capacitor C1, then LINEVDD and VMID decoupling capacitors.
3. If VMID is decoupled to AVDD, the capacitance value of the decoupling capacitor should be chosen so that VMID will
collapse at the same rate or quicker than AVDD at power off
4. Capacitor types should be chosen carefully. Capacitors with very low ESR are recommended for optimum
performance.
RECOMMENDED ANALOGUE LOW PASS FILTER
Figure 17 Recommended Analogue Low Pass Filter (one channel shown)
An external single-pole RC filter is recommended if the device is driving a wideband amplifier.
Other filter architectures may provide equally good results.
The filter shown in Figure 17 has a -3dB cut-off at 105.26kHz and a droop of 0.15dB at
20kHz. The typical output from the WM8532 is 2.04Vrms – when a 10kΩ load is placed at the
output of this recommended filter the amplitude across this load is 1.93Vrms.
