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CXA1372BQ/BS

DEFECT circuit

After inversion, RFI signal is bottom held by means of the long and short time constants. The long time-

constant bottom hold keeps the mirror level prior to the defect.

The short time-constant bottom hold responds to a disc mirror defect in excess of 0.1ms, and this is

differentiated and level-shifted through the AC coupling circuit.

The long and short time-constant signals are compared to generate at mirror defect detection signal.

RFO

a

b

DEFECT AMP

CC1

CC2

DFCT

CB

0.01µ

0.033µ

DEFECT COMPARATOR

DEFECT BOTTOM

HOLD

e

c

d

e

d

c

b

a

BOTTOM

HOLD (1);

Solid line CC1

DEFECT

AMP

RFO

DEFECT

BOTTOM

HOLD (2);

Dotted line CC2

H

L

34

35

37

40

30