AK5358A_08 Datasheet, PDF (15/18 Pages) Asahi Kasei Microsystems – 96kHz 24-Bit ΔΣ ADC

[AK5358A]
1. Grounding and Power Supply Decoupling
The AK5358A requires careful attention to power supply and grounding arrangements. Alternatively if VA and VD are
supplied separately, the power up sequence is not critical. AGND and DGND of the AK5358A must be connected to
analog ground plane. System 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 AK5358A as possible, with the
small value ceramic capacitor being the nearest.
2. Voltage Reference
The voltage input to VA sets the analog input range. VCOM are 50%VA and normally connected to AGND with a 0.1μF
ceramic capacitor. A capacitor 2.2μF is attached to VCOM pin. No load current may be drawn from these pins. All
signals, especially clocks, should be kept away from the VCOM pin in order to avoid unwanted coupling into the
AK5358A.
3. Analog Inputs
The ADC inputs are single-ended and internally biased to the common voltage (50%VA) with 20kΩ (typ@fs=48kHz)
resistance. The input signal range scales with the supply voltage and nominally 0.6xVA Vpp (typ). The ADC output data
format is 2’s complement. The internal HPF removes the DC offset.
The AK5358A samples the analog inputs at 64fs (@fs=48kHz). The digital filter rejects noise above the stop band except
for multiples of 64fs. The AK5358A includes an anti-aliasing filter (RC filter) to attenuate a noise around 64fs.
MS0511-E-02
- 15 -
2008/01