Sony CXA2555Q Datasheet
RF Amplifier for CD Player/CD-ROM
For the availability of this product, please contact the sales office.
Description
The CXA2555Q is an IC for RF signal processing
of CD player and CD-ROM.
Features
• Wide-band RF AC amplifier
(RF AC signal fc ≥ 20MHz)
• 4-mode RF equalizer (active filter type)
• RF equalizer boost amount and cut-off frequency
adjustable
• EFM time constant adjustable (switching function
provided)
• Peak hold time constant of mirror circuit adjustable
• Tracking error amplifier cut-off frequency adjustable
• Tracking error amplifier voltage gain adjustable
• Center error amplifier
• APC (Automatic Power Control) function
• APC ON/OFF control
• Supports laser coupler
Absolute Maximum Ratings
• Supply voltage VCC 7V
•Storage temperature Tstg –65 to +150 °C
• Power consumption PD 800 mW
Applications
• CD players
• CD-ROM drives
Functions
• RF summing amplifier
• RF equalizer
• Focus error amplifier
• Tracking error amplifier
• Center error amplifier
• Mirror detection function
• APC circuit
CXA2555Q
32 pin QFP (Plastic)
Operating Conditions
• Supply voltage VCC – GND 3.0 to 5.5 V
• Operating temperature Topr –20 to +75 °C
Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by
any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the
operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits.
– 1 –
E96730B76
Block Diagram
CXA2555Q
LD
PD
PD1
PD2
GND
TE1
2627
FILTER
CONTROL
80k
22k
51k
VCC
27p
15
FC C
1.0V
20k
VC
25
MODE
CC
V
16
APC ON
SW
VCC
24
23
22
21
20
19
18
17
MODE 1
MODE 2
RFO 1
RFO 2
V
CC
MIRR
CP
MIRR T
10k
29
VC
73.34k
12
EQ IN
44p
Open only for
L/L mode
RF C
28
VCA
CONTROL
MIXER LPF VCA
VCC
VC
HOLD
PEAK
10p
VC
40k
1.25V
40k
320k
2p
/BOT
20k
16k
16k
164k
13
BST C
BOOST
CONTROL
80k
80k
80k
1.3V
VC
20k
VC
87k
174k
14
40k
VS
40k
27p
RFO
32
1
2
3
4
5
E
6
F
7
GND
8
VC
APC ON
VC
10k
VC
20k
23k
9
RFI
31
18k
VC
56k 10k
1k
VC
20k
20k 10k
20k
10
SUM OUT
30
LPF DELAY
HPF BOOST
VS
39k
44k
1.25V
10k
55k56k
VCA
VCA
11
CE IN
CE1
CE
TE C
– 2 –
TE
FE B
FE
VC
Pin Description
CXA2555Q
Pin
No.
Symbol I/O Equivalent circuit Description
10k
1 LD APC amplifier output.
PD
2
O
I
3
1
2
147 20k
8k
1k
20k
10k
55k
10k
APC amplifier input.
3
4
7
5
6
8
12
13
PD1
PD2
GND
E
F
TE1
TE C
TE
4
I
147
I
16k
Input of RF summing amplifier
and focus error amplifier.
16k
174k
164k
Ground.
5
147
147
6
Tracking error amplifier input for
I
I
O
13
I
160k147
O
36.7k
147
VCA
147
Pins 5 and 6; tracking error
amplifier output for Pin 8;
tracking error amplifier low-
8
frequency gain setting for Pin
12; tracking error amplifier
output for Pin 13.
12
– 3 –
CXA2555Q
Pin
No.
10
11
Symbol I/O Equivalent circuit Description
9
CE IN
CE1
CE
1415FE B
FE
9
I
O
O
11
O
O
147
164k
174k
Center error amplifier input for
20k147
147
pin 9; inverting amplifier output
10
for pin 10; non-inverting
amplifier output for pin 11.
20k
147
14
Focus bias adjustment for Pin
14; focus error amplifier output
147
15
for Pin 15.
16
VC
17 MIRR T
120
O
120
147
I
17
120k 80k
16
VCC
10k
10k
(Vcc + GND)/2 DC voltage
output.
Peak hold time constant
adjustment.
– 4 –
CXA2555Q
Pin
No.
Symbol I/O Equivalent circuit Description
18 CP
19 MIRR Mirror comparator output.O
VCC Power supply.
20
80k1.5k
I
147
Connects a mirror hold
capacitor.
Non-inverted input of mirror
comparator.
18
20k
40k
100k
3k
147
19
2122RFO 2
RFO 1
23 MODE 2 I
24 MODE 1 I
147
21
O
O
147
22
Buffer switch output for the RF
time constant setting for Pin 21.
ON when Pins 23 and 24 are
connected to GND.
EQ signal output for Pin 22.
Double-speed mode switching
input.
147
23
147 10k
24
10k
40k
40k
Mode 1 Mode 2
× 1
× N
× 1.5N
× 2.0N
GND
VCC
GND
VCC
GND
GND
VCC
VCC
N is varied according to the
external resistor connected to
Pin 26.
25 APC ON I
25
147
100k
– 5 –
Switching pin for APC amplifier
ON/OFF.
OFF when connected to Vcc;
ON when connected to GND.
CXA2555Q
Pin
No.
26
Symbol I/O Equivalent circuit Description
FC C I
27 BST C
5k
5k5k
147
27
26
5k
I
Input to set the RF equalizer
LPF cut-off frequency.
Sets the high-frequency boost
amount of RF equalizer.
28 RF C
29 EQ IN RF equalizer input.I
SUM
30
OUT
I
28
29
20k
10k
147
430
147
2k
10k
10k
O
20k
147
30
Sets the low-frequency gain of
RF amplifier and RF equalizer.
RF summing amplifier output
inversion.
– 6 –
CXA2555Q
Pin
No.
Symbol I/O Equivalent circuit Description
31 RFI
32 RFO
39k
I
31
O
147 18k
44k
15k
15k
147
32
Mirror circuit input.
The RF summing amplifier
output is input.
RF signal output.
Eye pattern check point.
– 7 –
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