PZ-50HV2E (serv.man11). Description of major IC functions - Sharp TV Service Manual (repair manual). Page 18

•

•

•

1

2

3

4

8

7

6

5

Xin

Xout

S1

LF

VDD

S0

FSOUT

VSS

FS78x

8 Pin SOIC Package

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 #)

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 (pin2) unconnected.

7/3

S0/S1

I

CMOS/TTL

Digital control inputs to select input frequency range and output frequency scaling.  Refer to 
Tables 7 and 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 multipled by 2X and 4X for FS782 and FS784 
respectively.

8

VDD

P

Power

Positive Power Supply

5

VSS

P

Power

Power Supply Ground