AK5356VN Asahi Kasei Microsystems, AK5356VN Datasheet - Page 14

• Manufacturer Part Number: AK5356VN
• Description: LOW POWER 20BIT ADC WITH MIC AMP & PGA
• Manufacturer: Asahi Kasei Microsystems

n MIC Block
1. Pre-Amp
2. Power Supply for MIC
MS0171-E-00
The Pre-Amp is non-inverting amplifier and internally biased to MVCM voltage with 100k (typ.). Gain of the
Pre-Amp can select +13dB, +18dB, +28dB or +33dB by PREG1-0 bits.
Pre-Amp gain value of L/R channels change by zero crossing detection or timeout independently. Timeout cycle is fixed
to 2048/fs (=46.8ms @ fs = 44.1kHz). Zero crossing detection is done by IPGA block. When PMADC bit is “0”, gain of
Pre-Amp changes immediately.
An external capacitor is needed to cancel DC gain. The cut-off frequency is determined by an internal resistor (Ri) and
an external capacitor (C1).
The power supply for microphone device is supplied from MPWR pin. The output voltage is typically 2.16V(= 0.8 x
MVDD at MVDD=2.7V). MPWR pin can supply the current up to 1mA. When PMMIC bit is “0”, the output current is
not supplied.
PREL pin
PRER pin
C1
+
Figure 9. Pre-Amp
Ri
- 14 -
Pre-Amp
-
+
Rf
To MICL/MICR pins
2002/08