ASAHI KASEI
[AK4319A]
SYSTEM DESIGN
Figure 8 shows the system connection diagram. An example of external analog filter is shown in Figure 9 .
An evaluation board[AKD4319A] is available in order to allow an easy study on the layout of a
surrounding circuit.
Figure 8 .Typical Connection Diagram
Notes:
- Power lines of AVDD and DVDD should be distributed separately from the point with low
impedance of regulator etc.
- When AOUT drives some capacitive load, some resistor should be added in series between
AOUT and capacitive load.
- All input pins except internal pull-down pins should not be left floating.
1. Grounding and Power Supply Decoupling
To minimize coupling by digital noise, decoupling capacitors should be connected to AVDD and DVDD,
respectively. AVDD is supplied from analog supply in system and DVDD is supplied from AVDD as shown
in Figure 8 . Alternatively if AVDD and DVDD are supplied separately, AVDD and DVDD should be
powered at the same time or AVDD should be powered earlier than DVDD. Analog ground and digital
ground should be connected together near to where the supplies are brought onto the printed circuit
board. Decoupling capacitors for high frequency should be placed as near as possible.
M0011-E-01
1998/6
- 13 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
