ak4342 AKM Semiconductor, Inc., ak4342 Datasheet - Page 25

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

ASAHI KASEI
Aux-out amplifiers are single-ended outputs and centered on VCOM voltage (0.45 x AVDD). Signal output voltage is
typically 700mVrms (@ AVDD = 3.3V, 0dBFS). The minimum load resistance is 10kΩ.
When the AVCMN bit is set to “0”, the common voltage of Aux-out amplifiers falls. When the AVCMN bit is set to “1”,
the common voltage rises to 0.45 x AVDD. A capacitor between the MUTET pin and ground reduces pop noise at
power-up. Rise/Fall time constant is in proportional to AVDD voltage and the capacitor at MUTET pin.
[Example]: A capacitor between the MUTET pin and ground = 1.0µF, AVDD=3.3V:
When PMAUX bit is set to “0”, the Aux-out amplifiers are powered-down, and the outputs (LAUX and RAUX pins) go
to “L” (AVSS). When the AMUTE bit is set to “1”, the outputs (LAUX and RAUX pins) are muted and become VCOM
voltage. When the AMUTE bit is set to “0”, the outputs are in normal operation.
(1) Aux-out amplifier power-up (PMAUX bit = “1”). The outputs are still AVSS.
(2) Aux-out amplifier common voltage rises up (AVCMN bit = “1”)
(3) Aux-out amplifier common voltage falls down (AVCMN bit = “0”)
(4) Aux-out amplifier power-down (PMAUX bit = “0”). The outputs are AVSS. If the power supply is switched off or
MS0506-E-02
Aux-out amp
Aux-out amplifier is powered-down before the common voltage goes to AVSS, some pop noise occurs.
Rise/fall time constant:
PMAUX bit
AVCMN bit
LAUX pin
RAUX pin
Figure 19. Power-up/Power-down Timing for Aux-out amplifier
(1) (2)
τ
= 100ms(typ), 300ms(max)
(3)
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(4)
[AK4342]
2006/07