AK5355VT AKM [Asahi Kasei Microsystems], AK5355VT Datasheet - Page 16

• Manufacturer Part Number: AK5355VT
• Description: LOW POWER 16BIT ADC
• Manufacturer: AKM [Asahi Kasei Microsystems]

ASAHI KASEI
[AK5355]
1. Grounding and Power Supply Decoupling
The AK5355 requires careful attention to power supply and grounding arrangements. VA is usually supplied from the
analog supply in the system. VD is a power supply pin to interface with the external ICs and is supplied from the digital
supply in the system. VSS of the AK5355 should be connected to the 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 AK5355 as possible, with the small value ceramic capacitor being the
nearest.
2. Voltage Reference
The input to VA Voltage sets the analog input range. A 0.1µF ceramic capacitor and a 10µF electrolytic capacitor are
normally connected to VA and VSS pins. VCOM is a signal ground of this chip. An electrolytic 2.2µF in parallel with a
0.1µF ceramic capacitor attached to these pins eliminates the effects of high frequency noise. No load current may be
drawn from the VCOM pin. All signals, especially clock, should be kept away from the VA, VD and VCOM pins in order
to avoid unwanted coupling into the AK5355.
3. Analog Inputs
The analog inputs are single-ended and the input resistance is 40kΩ (typ). The input signal range scales with nominally
(0.6 x VA) Vpp (typ) @ GAIN = 0dB centered around the internal common voltage (typ. 0.45 x VA). Usually, the input
signal cuts DC with a capacitor. The cut-off frequency is fc=(1/2πRC). The ADC output data format is 2’s complement.
The DC offset including the ADC’s own DC offset is removed by the internal HPF (fc=3.4Hz@fs=44.1kHz).
MS0113-E-01
2005/01
- 16 -