Optical disc ICs
(3) APC block and AGC block
BA6386K
The initial setting for V1 is 1.2V. When PL-BL (the RF AC
amplitude) exceeds a certain value (VAGC), then AGC low-
ers V1 and suppresses the laser power. The value of VAGC
is Iagc 20k, where Iagc is set by the formula given be-
low.
Iagc = 1.2
1.4k)R18
When R18 = 10kΩ, Iagc = 50µA and VAGC = 1V.
When defect turns high, Tr1 turns OFF.
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