[AK4425A]
1. Grounding and Power Supply Decoupling
VDD and AVDD are supplied from the analog supply and should be separated from the system digital supply.
Decoupling capacitors, especially 0.1μF ceramic capacitors for high frequency bypass, should be placed as near to VDD
and AVDD as possible. The VSS1 and VSS2 must be connected to the same analog ground plane. Power-up sequence
between VDD and AVDD is not critical.
2. Analog Outputs
The analog outputs are single-ended and centered around the VSS (ground) voltage. The output signal range is typically
2.2Vrms (typ @AVDD=5V). The internal switched-capacitor filter (SCF) and continuous-time filter (CTF) attenuate the
noise generated by the delta-sigma modulator beyond the audio passband. Using single a 1st-order LPF (Figure 16) can
reduce noise beyond the audio passband.
AK4425
470
Analog
Out
AOUT
2.2Vrms (typ)
2.2nF
(fc = 154kHz, gain = -0.28dB @ 40kHz, gain = -1.04dB @ 80kHz)
Figure 16. External 1st order LPF Circuit Example
MS1127-E-01
2011/03
- 24 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
