AK4537 Datasheet, PDF (31/76 Pages) Asahi Kasei Microsystems – 16-Bit ΔΣ Stereo CODEC with MIC/HP/SPK-AMP

ASAHI KASEI
[AK4537]
„ BEEP Input
When the PMBPS bit is set to “1”, the stereo beep input is powered up. And when the BPSHP bit is set to “1”, the input
signals from the BEEPL and BEEPR pins are mixed to Headphone outputs. When the BPSSP bit is set to “1”, the signal
of (BEEPL + BEEPR)/2 is input to Speaker-amp. When the PMBPM bit is set to “1”, mono beep input is powered up.
And when the BPMHP bit is set to “1”, the input signal from the BEEPM pin to Headphone-amp. When the BPMSP bit is
set to “1”, the signal from the BEEPM pin is input to Speaker output. The external resisters Ri adjust the signal level of
each BEEP input that are mixed to Headphone and Speaker outputs.
The signal from the BEEPM pin is mixed to the Headphone-amp through a –20dB gain stage. The signal from the
BEEPM pin is mixed to the Speaker-amp without gain. The internal feedback resistance is 20k ± 30%Ω.
Ri
BEEPL
Ri
BEEPR
Ri
BEEPM
Rf = 20kΩ
Rf = 20kΩ
BPSHP
HPL
MIX
BPMHP
-20dB
HPR
MIX
BPSHP
Rf = 20kΩ
BPSSP
1/2
SPK
1/2
MIX
AK4537
BPMSP
Figure 25. Block Diagram of BEEP pins
MS0202-E-04
- 31 -
2005/04