ASAHI KASEI
[AK8817/18]
(13) Video Amp
AK8817/18 has Video amp that can drive 150ohm with Low pass filter. It can also possible to compensate SAG distortion.
To compensate SAG external capacitor is 47uF and 1uF as shown following figure. Recommendation voltage when SAG
compensation circuit is used is 3V or more.
VOUT pin and SAG pin should be shorten when SAG Compensation is not used. Output pin should make AC coupling.
SAG Compensation circuit can be set on or off with setting register.
In case of not using internal Video amp (Only DAC use case), Video Amp becomes power down. In this case SAG and
VOUT should be Open.
AK8817
SAG
VOUT
AK8817
SAG
VOUT
1uF
75ohm
100uF 75ohm
47uF
SAG Compensation ON
SAG Compensation Off
VAMPMD[1:0]
00
Operation
Conditions
Video Amp OFF + SAG Compensation OFF
Only DAC output
Recommendation Voltage of
DVDD/AVDD is 3v or more.
SAG pin and VOUT should be
shorten.
01
Video AMP ON + SAG Compensation ON
10
11
Video Amp ON + No SAG Compensation
Reserved
Rev.001E
22
2009 / 12
AKM [ ASAHI KASEI MICROSYSTEMS ]
