AK4537 Datasheet, PDF (67/76 Pages) Asahi Kasei Microsystems – 16-Bit ΔΣ Stereo CODEC with MIC/HP/SPK-AMP

ASAHI KASEI
[AK4537]
„ Headphone-amp Output
FS2-0 bits
(Addr:05H, D7-5)
BST1-0 bits
(Addr:06H, D3-2)
ATTL7-0 bits
(Addr:0CH 0DH, D7-0)
PMDAC bit
(Addr:01H, D0)
HPL/R bit
(Addr:03H, D1-0)
PMHPL/R bits
(Addr:01H, D2-1)
000
(1)
00
(2)
0000000
(3)
(4)
(5)
(6)
XXX
XX
XXXXXXX
00
(12)
(11)
(10)
(9)
HPL/R pins
External Mute
Normal Output
(7)
(8)
E xa m p le :
X ’tal a nd P LL are us ed.
S a m p ling F re q ue nc y : 4 4 .1 kH z
D A T T C b it = “1 ”(d e f a ult)
D igital A tte nua to r Le ve l : -8 dB
B a s s B o o s t L e v e l : M id d le
D e-em phases respo nse : O FF
S o ft M ute T im e : 1 02 4/fs
(1 ) A d d r:0 5 H , D ata:0 0 H
(2 ) A d d r:0 6 H , D ata 1 9 H
(3 ) A d d r:0 C H , D ata 1 0 H
(4 ) A d d r:0 1 H , D ata 6 1 H
(5 ) A d d r:0 2 H , D ata 8 0 H
(6 ) A d d r:0 1 H , D ata 6 7 H
(7 ) R e le a s e e xte rn a l M u te
P la yb a c k
(8 ) E n a b le e xte rn a l M u te
(9 ) A d d r:0 1 H , D ata 6 1 H
(1 0 ) A d d r:0 2 H , D ata 8 3 H
(1 1 ) A d d r:0 1 H , D ata 6 0 H
(1 2 ) A d d r:0 6 H , D ata 1 1 H
Figure 55. Headphone-Amp Output Sequence
<Example>
At first, clocks should be supplied according to “Clock Set Up” sequence.
(1) Set up a sampling frequency (FS2-0 bits) if PLL mode is used.
(2) Set up the low frequency boost level(BST1-0 bits)
(3) Set up the digital volume(Addr : 0CH and 0DH)
At DATTC bit = “1”(default), ATTL7-0 bits of Address 0CH control both Lch and Rch attenuation level.
(4) Power up DAC : PMDAC bit = “0” → “1”
(5) Power up headphone-amp : HPL bit = HPR bit = “1” → “0”
Output voltage of headphone-amp is still HVSS.
(6) Rise up the common voltage of headphone-amp : PMHPL bit = PMHPR bit = “0” → “1”
The rising time after power up Headphone-amp depends on the capacitor value connected with the MUTET
pin. When this capacitor value is 1.0µF, the time constant is τr = 100ms(typ), 250ms(max).
(7) Release the external mute.
(8) Enable the external mute.
(9) Fall down the common voltage of headphone-amp : PMHPL bit = PMHPR bit = “1” → “0”
The rising time after power up Headphone-amp depends on the capacitor value connected with the MUTET
pin. When this capacitor value is 1.0µF, the time constant is τf = 100ms(typ), 250ms(max).
If the power supply is powered off or Headphone-Amp is powered-down before the common voltage goes to
GND, some POP noise occurs. It takes 2times of τf that the common voltage goes to GND.
(10) Power down headphone-amp : HPL bit = HPR bit = “0” → “1”
(11) Power down DAC : PMDAC bit = “1” → “0”
(12) Off the low frequency boost level (BST1-0 bits = “00”)
MS0202-E-04
- 67 -
2005/04