values. New layouts using the CLC020 will benefit from the

greatly reduced ancilliary component count and more com-

pact layout.

The CLC020 does not require external VCO filtering compo-

nents. The external VCO filtering components at pin 17 of

the GS9022 may remain connected to the CLC020 without

complications. It is suggested that these be removed from

the circuit board. The CLC020 uses pin 17 for its test pattern

generator enable function. You will find the TPG function

very useful when you make this change.

Remove the C

The CLC020 uses pin 26 as the BIST pass/fail indicator

output. You may attach a LED as an indicator to this pin, if

desired. LED current should be limited to 10 mA maximum.

The same LED type and current limiting resistor shown in

Figure 8 at the Lock Detect output may be used for this

indicator function.

Remove any capacitor attached to pin 19. A capacitor at-

tached to pin 19 will cause distortion of the output V

The former data rate setting resistor, R

functions as the output level setting resistor, R

changed to a 1.69 k

Ω, 1% value for correct output level

setting.

The input series resistors and the P

tor used with the GS9022 are not needed for the CLC020.

These components should be removed from the circuit

board and the resistors replaced by short circuits (0

Ω resis-

tors). These series resistors will increase input signal rise

and fall times if left on the board.

The CLC020 has current-mode serial cable driver outputs.

These outputs have very high internal generator resistance

as one would expect of a current source. Though these

current-mode outputs can produce the equivalent drive volt-

ages into the load, it is necessary to change and simplify the

typical GS9022 output circuit normally recommended for that

device. The output load resistors at pins 22 and 23 must be

changed to 75

Ω, 1% values. These resistors become the

back-matching loads across which the CLC020’s outputs

develop drive voltage. The series back-matching resistors

used on the GS9022 should be removed and replaced with

short circuits. The risetime compensating capacitors across

these resistors should be removed.

Pin 28 on the CLC020 is V

negative supply or ground. On layouts designed to mount

the GS9022, the series R-C network connected to this pin

should be replaced by short circuits (0

Ω resistors).

The pull-up resistor connected to the Lock Detect output, pin

14, should be removed. It may be replaced by a LED and

current limiting resistor connected to V

indicator is desired.

The CLC020 has an internal pull-down at the Sync Detect

Enable input and may be left unconnected in SMPTE video-

only applications.

The CLC020 has independent power supply pins for the

VCO, V

output driver negative supply, V

driver positive supply, V

On new layouts, additional power supply filtering may be

added at these pins, if desired.

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