AK4640_05 Datasheet, PDF (35/78 Pages) Asahi Kasei Microsystems – 16-Bit ΔΣ CODEC with MIC/HP/SPK-AMP

ASAHI KASEI
[AK4640]
„ 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-amp. When the BPSSP bit is set to “1”, the input
signals from the BEEPL and BEEPR pins are mixed 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 is mixed to Headphone-amp.
When the BPMSP bit is set to “1”, the input signal from the BEEPM pin is mixed to Speaker-amp. The external resisters
Ri adjust the signal level of each BEEP input that is mixed to Headphone and Speaker outputs. When BPMSP bit is “1”,
the offset voltage between SPP and SPN pins may be large. Therefore, it is recommended that BPMSP bit be set to “0”
while the beep signal is not output.
Path
Gain
BEEPL Æ HPL; BEEPR Æ HPR
BEEPL Æ SPP/N; BEEPR Æ SPP/N
BEEPM Æ HPL; BEEPM Æ HPR
BEEPM Æ SPP/N
(16.7k / Ri) ± 50%
(26.7k / Ri) ± 50%
(1.67k / Ri) ± 50%
(44.7k / Ri) ± 50%
Table 20. BEEP input gain
Example (Ri=20k)
−1.6dB ± 6dB
+2.5dB ± 6dB
−21.6dB ± 6dB
+7.0dB ± 6dB
Ri
BEEPL
Ri
BEEPR
Ri
BEEPM
20k(typ)
20k(typ)
-1.6dB
-1.6dB
BPSHP
BPMHP
-1.6dB
2k(typ)
+2.5dB
+2.5dB
+27.0dB
AK4640
BPSHP
BPSSP
BPMSP
HPL
MIX
HPR
MIX
SPK
MIX
Figure 24. Block Diagram of BEEP pins
MS0273-E-02
- 35 -
2005/04