AK4342 Datasheet, PDF (23/43 Pages) Asahi Kasei Microsystems – 24-Bit Stereo DAC with HP-AMP & 2V Line-Out

ASAHI KASEI
[AK4342]
„ Headphone Output
Power supply voltage for headphone amplifiers is applied from HVDD and HVEE pins. HVEE pin must be connected
with PVEE pin directly. PVEE pin outputs the negative voltage generated by the internal charge pump circuit. The
headphone amplifier is single-ended outputs and centered on 0V(HVSS). Therefore, the capacitor for AC-coupling can be
removed. The minimum load resistance is 16 Ω.
1. Analog output volume
These volumes are channel independent can gain/attenuate the DAC output signal from +6dB to –48dB. (See Table 10)
Changing levels don’t have any pop noise. The transition time is selected by PTS1-0 bits and sampling frequency (See
Table 2 and Table 15).
At PGAC bit = “1”, PGAL4-0 bits control both Lch and Rch attenuation level, while register values of PGAL4-0 bits are
not written to PGAR4-0 bits. At PGAC bit = “0”, PGAL4-0 bits control Lch level and PGAR4-0 bits control Rch level.
When PGAC bit is changed, the transition of volume is executed via soft changes, and PGAL4-0 and PGAR4-0 bits
should be changed after the transition time passes.
When changing PGAC bit = “0” Æ “1” (In case of “PGAL4-0 bit ≠ PGAR4-0 bit”), the gain of right channel is changed
to the register setting of PGAL4-0 bits. When changing PGAC bit = “1” Æ “0” (In case of “PGAL4-0 bit ≠ PGAR4-0
bit”), the gain of right channel is changed to the last register setting which is written into PGAR4-0 bits.
PGAL4-0 bits
PGAR4-0 bits
GAIN/ATT (dB)
Step
Level
1FH
+6
1EH
+5
•
•
1AH
+1
1dB
16
19H
0
18H
-1
•
•
10H
-9
0FH
-10
0EH
-12
•
•
2dB
11
06H
-28
05H
-30
04H
-32
03H
-36
02H
-40
4dB
5
01H
-44
00H
-48
Table 10. Volume Setting for headphone amplifier
Default
2. Mute Function
When HMUTEL/HMUTER bit is set to “1”, the headphone amplifier (HPL/HPR pins) goes to ground level (0V). This
function is independent L/R channels. This mute time depends on the setting of PTS1-0 bits and sampling
frequency(FS3-0 bits). When HMUTEL/HMUTER bit is set to “0”, the outputs are in normal operation.
3. Power-up/down
Headphone amplifiers are powered-up/down by PMHP bit, HPL and HPR pins go to HVSS(0V). The power-on/off time
depends on the setting of PUT1-0 bits and sampling frequency (FS3-0 bits). The power-up/down of headphone amplifiers
should be done in the mute state (HMUTEL bit = HMUTER bit = “1”).
MS0506-E-02
- 23 -
2006/07