cxa2555q Sony Electronics, cxa2555q Datasheet - Page 14

• Manufacturer Part Number: cxa2555q
• Description: Rf Amplifier For Cd Player/cd-rom
• Manufacturer: Sony Electronics

Description of Functions
RF Block
The RF signal processing is performed by this circuit.
The output is separated to AC and DC. The AC is the capacitance-coupled input via the equalizer circuit and
used for the EFM demodulation signal processing. The DC contains the DC component and is used for the
mirror, defect and FOK signal processings.
The VCA function is provided for both the AC and DC signal processing systems. Pin 28 is the control voltage
input pin. (See the characteristics graphs on page 19 and page 20 for the gain and control voltage.)
RF Equalizer Block Diagram is as shown below:
The equalizer function is provided for the AC signal processing system for the EFM signal demodulation.
The each filter is constructed in the Bessel type which has the little group delay difference.
The boost frequency and boost amount can be set by the external resistors connected to Pins 26 and 27.
(See the characteristics graphs on page 19 for the boost frequency and boost amount.)
The transmittance for each filter is as follows:
HPF: (KS
LPF1: (2.94933 ) / (S
LPF2: (3.32507 ) / (S
LPF3: (4.20534 ) / (S
LPF4: (1.68536 ) / (S + 1.68536)
EQ IN
2
) / (S
2
+ 3.22597S + 2.94933)
LPF1
FC C
FC C
HPF
2
2
2
+ 3.22597S + 2.94933)
+ 2.75939S + 3.32507)
+ 1.82061S + 4.20534)
DELAY
BST C
Boost
MIXER
– 14 –
LPF2
FC C
LPF3
FC C
LPF4
FC C
RF C
VCA
EQ OUT
CXA2555Q