PDU-50WX2
94
1
2
3
4
8
7
6
5
Xin
Xout
S1
LF
VDD
S0
FSOUT
VSS
FS78x
8 Pin SOIC Package
Pin No.
Pin Name
I/O
TYPE
Description
1/2
Xin / Xout
I/O
Analog
Pins form an on-chip reference oscillator when connected to
terminals of an external parallel resonant crystal. Xin may be
connected to TTL/CMOS external clock source. If Xin
connected to external clock other than crystal, leave Xout (pin 2)
unconnected.
7/3
S0 / S1
I
CMOS/TTL
Digital control inputs to select input frequency range and output
frequency scaling. Refer to Tables 7 & 8 for selection. S0 has
internal pulldown. S1 has internal pullup.
4
LF
I
Analog
Loop Filter. Single ended tri-state output of the phase detector. A
two-pole passive loop filter is connected to Loop Filter (LF).
6
FSOUT
O
CMOS/TTL
Modulated Clock Frequency Output. The center frequency is the
same as the input reference frequency for FS781. Input
frequency is multiplied by 2x and 4x for FS782 and FS784
respectively.
8
VDD
P
Power
Positive Power Supply.
5
VSS
P
Power
Power Supply Ground
Phase
Detector
VCO
1(3)
2(4)
Xin
Xout
10 pF.
Reference
Divider
8 pF
8 pF
250 K
VCO / N
Modulation
Control
Input Control Logic
Output
Divider
and
Mux
Power Contol
Logic
3(5)
7(1)
8(2)
5(7)
4(6)
VDD
S0
S1
FSOUT
Loop Filter
VSS
6(8)
VSS
VDD
(TSSOP Pin #)
•
Pin Assignment (Top View)
FS781BZB (DIGITAL VIDEO ASSY : IC1802)
• Low EMI Clock IC
•
Pin Function
•
Block Diagram
Summary of Contents for PDU-50WX2
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