S5L1462B Datasheet, PDF (38/43 Pages) Samsung semiconductor – CD and DVD playback

S5L1462B
RF ENVELOPE CIRCUIT
RF SIGNAL PROCESSOR
VCC
ABCDI
ENVB
BOTTOM
PEAK
ENVP
-
3.5dB
+
LEVEL
SHIFT
ENV
GND
• This circuit detects the RF ENVELOPE RF signal's ENVELOPE. It has the ENVELOPE detection output for
adjusting the SERVO's FOCUS BIAS.
• The PEAK HOLD and BOTTOM HOLD's response time constant is decided by the CAPACITOR value connected
to the external block ENVP, ENVB, and the standard response frequency is 10 kHz (when C = 0.01uF).
• The LEVEL SHIFT circuit is to make sure ENVOUT starts near 0Volts instead of at Vc LEVEL when there is no
RF signal.
• During Focus Un-locking, the circuit outputs to the ENV output block after 3.5dB GAIN UP.
• The ENV signal is output to the ENV output block during Focus Un-locking after 3.5dB GAIN UP.
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