AK4709 Datasheet, PDF (20/42 Pages) Asahi Kasei Microsystems – Low Power AV SCART Switch

[AK4709]
■ Analog output block
The AK4709 has chargepump circuit generating negative power supply rail from a 3.3V(typ) power supply. (Figure 7)
It allows the AK4709 to output audio signal centered at VSS (0V, typ) as shown in Figure 8. Negative power generating
circuit (Figure 7) needs 1.0uF capacitors (Ca, Cb) with low ESR (Equivalent Series Resistance). When using capacitors
with a polarity, the positive side should be connected to CP and VSS2 for capacitor Ca and Cb, respectively. When the
MUTE bit = “1”, the charge pump circuit is in power down mode and its analog outputs become VSS (0V, typ).
AK4709
VD
Charge
Pump
Negative Power
CP
CN VSS2
VEE
Cb
(+)
1 uF
1uF Ca
(+)
Figure 7. Negative power generate circuit
AK4709
0V
TVOUTR/TVOUTL
(VCROUTR/VCROUTL)
2Vrms
Figure 8. Audio signal output
MS1319-E-00
- 20 -
2011/07