AKD8130 Datasheet, PDF (3/6 Pages) Asahi Kasei Microsystems – Evaluation Board for AK8130

AKD8130
The brand name
of AKEMD’s IC’s
3. Smoothing filter for PWM signal
There are patterns to configure a passive smoothing filter for PWM signal which is supplied to control the
oscillation frequency of VCXO. It is necessary to mount resistor and condenser on these patterns and also
input PWM signal between VIN and VSS12 pins when this filter is employed. It is also possible to control the
voltage without using this filter. In this case, please input DC voltage directly to CN2 pin over VSS8 pin.
4. Dummy capacitor loads
There are several dummy capacitor loads, C23 through C27. It is useful to measure clock performance or
current consumption by loading capacitor which is virtually assumed in the system. It is important to take line
capacitance into account and it is approximately 5pF. Consequently if there is 25pF capacitance assumed in
the system, another 20pF capacitor needs to be mounted. Each clock outputs from AK8130 lead to J8 through
J12. Chassis mount test jacks for miniature probe (Tektronix 131-0258-00) are available by mounting there.
Table1.2
Jn/Cn
J8/C8
J9/C9
J10/C10
J11/C11
J12/C12
Connect to:
AK8130 Pin11
AK8130 Pin10
AK8130 Pin7
AK8130 Pin8
AK8130 Pin9
5. Quartz oscillator foot pattern
There are 4 types of boards depending on quartz oscillator. VCXO is controlled its oscillation frequency by
capacitance fluctuation of quartz oscillator. Therefore parasitic capacitance exists on the line pattern affects
the oscillation performance. However in this board, ground patterns under quartz oscillator and Pin1/Pin16 is
removed to minimize the unwanted affection. It is possible to check and tune characteristics of VCXO by using
this board because those characteristics are adjustable by changing load capacitor, C17 and C18, to the
suitable value. Please refer VCXO characteristic as a example.
6. AK811x foot pattern
It is possible to mount AK811x series 1ch-PLL on this board.
Jan-08
AKD0598-E-00
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