AK4543 Datasheet, PDF (28/31 Pages) Asahi Kasei Microsystems – AC’97 Rev 2.1 Multimedia Audio CODEC

[ASAHI KASEI]
[AK4543]
1. Grounding and Power Supply Decoupling
AVdd1 and AVdd2 should be connected and derived from same AVdd. And DVdd1 and DVdd2 also should
be connected and derived from same D V d d. Analog ground and digital ground should be connected together
near to where the supplies are brought onto the printed circuit board. Decoupling capacitors should be as near to
the AK4543 as possible, with the small value ceramic capacitor being the nearest.The most important capacitor
placements are on the Vref pin and AVdd pins.
No specific power supply sequencing is required on the AK4543.
2. On-chip Voltage Reference
The on-chip voltage reference is output on the VRADDA, Vref pins are used for decoupling. A electrolytic capacitor
less than 10uF in parallel with a 0.1 uF ceramic capacitor attached to these pins eliminates the effects of high
frequency noise. No load current may be drawn from VRADDA, or Vref pins. All signals, especially clocks, should
be kept away from the VRADDA, and Vref pins in order to avoid unwanted coupling into delta-sigma modulators.
3. Codec ID configuration Pin 45,46
ID1#(pin 46)
Physical
Logic
Connection
Value
NC
0
NC
0
GND
1
GND
1
ID0#(pin45)
Physical
Logic
Connection
Value
NC
0
GND
1
NC
0
GND
1
Configuration
Primary
Secondary ID01
Secondary ID10
Secondary ID11
4.Anlog input
Since many analog levels can be as high as 2Vrms, the circuit shown below can be used to attenuate the analog
input 2Vrms to 1Vrms which is the maximum voltage allowed for all the stereo line-level inputs.
J15
LINE_IN_L
J4
LINE_IN_R
5.SEL_CMOS#(48pin)
When DVDD is 3.3V for support of CMOS level, Pin 48 must be open.
Pin 48 must be DGND as the below figure in the case of DVDD is 5.0V for TTL level
This SEL_COMS# has to be fixed before powering up the AK4543.
6.PC_BEEP
If PC_BEEP isn’t used, this input pin should be NC(open) or connected to Analog-Ground via capacitor. In this
case, the register for PC- Beep(04h,D15) should be set to mute on ”1”. (Note that the default of PC_BEEP is mute
off.)
In addition, when PC_BEEP is connected through capacity to Analog-Ground, PC_BEEP is recommended to be
separated from other non-used input pins.
<M0046-E-01>
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1999/01