ak4342 AKM Semiconductor, Inc., ak4342 Datasheet - Page 16

• Manufacturer Part Number: ak4342
• Description: 24-bit Stereo Dac With Hp-amp & 2v Line-out
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
The external clocks required to operate the AK4342 are MCLK, BICK and LRCK. MCLK should be synchronized with
LRCK but the phase is not critical. The MCLK is used to operate the digital interpolation filter, delta-sigma modulator,
charge pump circuit and counter for transition time. The MCLK frequency is detected from the relation between MCLK
and LRCK automatically. The Half speed, the Normal speed and the Double speed mode are selected with the DFS1-0
pins (Table 1). The sampling frequency is selected with the FS3-0 bits. (Table 2)
When the states of DFS1-0 bits change in the normal operation mode, the AK4342 should be reset by PDN pin or
PMDAC bit.
For low sampling rates, DR and S/N degrade because of the out-of-band noise. DR and S/N are improved by setting the
half speed mode (DFS1-0 bits = “10”)
External clocks (MCLK, BICK and LRCK) should always be present whenever the DAC, headphone amp, lineout amp or
charge pump circuits is in normal operation mode (PMDAC bit = “1”, PMHP bit = “1”, PMLO bit = “1” or PMCP bit =
“1”). If these clocks are not provided, the AK4342 is not operated normally, especially, DAC may draw excess current
due to dynamic refresh of internal logic. If the external clocks are not present, the DAC, headphone amp, charge pump
circuit and lineout amp should be in the power-down mode (PMDAC bit = PMHP bit = PMLO bit = PMCP bit = “0”).
MS0506-E-02
System Clock
DFS1 bit
0
0
1
1
FS3 bit
Table 3. Relationship between Clock Mode and S/N of Lineout, Headphone and Aux-out
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
DFS0 bit
Normal Speed
FS2 bit
Half Speed
0
1
0
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Mode
Normal Speed
Double Speed
Table 2. Set up of Sampling Frequency
Half Speed
FS1 bit
Table 1. System Clock Example
Mode
OPERATION OVERVIEW
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Lineout
89dB
99dB
S/N (fs=8kHz, 20kLPF + A-weighted)
FS0 bit
60 ∼ 96kHz
8 ∼ 48kHz
8 ∼ 24kHz
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0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
fs
Reserve
Headphone
87dB
95dB
Sampling Frequency
11.025kHz
256/384/512/768fs
128/192/256/384fs
MCLK Frequency
(Reserve)
(Reserve)
22.05kHz
(Reserve)
(Reserve)
44.1kHz
88.2kHz
32kHz
48kHz
64kHz
96kHz
16kHz
24kHz
12kHz
8kHz
512/768fs
Aux-out
87dB
95dB
Default
Default
[AK4342]
2006/07