AKD4551 Datasheet, PDF (2/17 Pages) Asahi Kasei Microsystems – EVALUATION BOARD REV.C FOR AK4551

ASAHI KASEI
[AKD4551]
n Input Circuit
External analog signal fed through the BNC connector is terminated by a resistor of 560 ohms. The resistor value should be
properly selected in order to meet the output impedance of the signal source.
AINL(AINR)
4.7u
470
560
2.2n
AINL(AINR)
Figure 2. Input buffer circuit on board
* AKM assumes no responsibility for the trouble when using the circuit examples.
n Analog Output Circuit
The AK4551 includes a combination of switched-capacitor filter (SCF) and continuous-time filter (CTF), so any external
filters are not required.
n Grounding and Power Supply Decoupling
To minimize the coupling by digital noise, VDD pin should be supplied from analog power supply in system. Decouling
capacitors should be connected to AK4551 as near as possible. Especially, the capacitor between VDD and VSS pins
should be connected nearest.
n Operation sequence
1) Set up the power supply lines.
[VA] (orange) = 2.2 ∼ 3.6V : for VDD of AK4551
[VP] (orange) = 2.2 ∼ 3.6V : for VP of 74HC4050
[VD] (red)
= 3.6 ∼ 5.0V : for logic
[AGND] (black) = 0V
: for analog ground (including VSS of AK4551)
[DGND] (black) = 0V
: for logic ground
Each supply line should be distributed from the power supply unit.
VP and VA must be same voltage level.
2) Set up the evaluation mode, jumper pins and DIP switches. (See the followings.)
3) Power on.
The AK4551 should be reset once bringing SW1,2 ( PWAD , PWDA ) “OFF” upon power-up.
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