AK4665A Datasheet, PDF (27/52 Pages) Asahi Kasei Microsystems – 20-Bit Stereo CODEC with MIC/HP-AMP

ASAHI KASEI
[AK4665A]
„ External Analog Input (LIN, RIN, MIN pins)
The input signals from LIN/RIN/MIN pins can be output from headphone and lineout. LIN/RIN/MIN input buffers are 2^nd
order LPF (fc=50kHz(typ)) in order to attenuate the high frequency noise of external analog input signals. DC component
of input signal should be cut by external capacitor. The cut-off frequency (fc) of HPF depends on the internal input
resistance (Ri) and the external capacitor value (C): fc=1/(2πRiC). The input resistance is 200kΩ±50%, The gain is
0dB(typ) for both Lineout and HP-Amp (HPG=LING bits = “0”).
When HPG bit = “1” and LING bit = “0”, the gain of HP-Amp is −5.5dB(typ).
When HPG bit = “0” and LING bit = “1”, the gain of LIN/RIN → HPL/HPR paths are −12dB(typ).
LIN/RIN/MIN input buffers powered-up when either bits of PMHPL, PMHPR and PMLO bits become “1”.
AK4665A
LIN/RIN/MIN pin
−
C
Ri
+
Lineout
HP-Amp
Figure 17. External Analog input circuit
MS0440-E-01
- 27 -
2006/05