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6. RF AMP. CXA1081M (X29-1890-05 : IC1)
6-2. Explanation of terminals (Vcc = 2.5V, VEE = DGND = -2.5V, VC = GND)
General
Structure
Functor
The
CXAt
eC
081M is an IC developed for use in Compact Disc
Bipolar silicon monolsthic IC
Input pin for the C-coupled signa output trom the RF summing amplifier
players.
It incorporates
a 3-spot
optical
pickup
RF output
amplifier, a focusing error amplifier, a tracking error amplifier,
F
'i
jan summing amplifier output pin
Used as the check port for the eye pattern
and other signal processing circustry, such as focus OK, mir-
e
RF amphfier
RF summing amplifier feedback input pin
ror, defect, and EFM comparator circuits, as well as a laser
© Focus OK detector circuit
P-sub/N-sub select pin for the LD (Laser Diode) (DC vottage' in N-sub mode!
APC
(Aut
diode
APC {Automatic Power Control) circust
©
Mirror detector circuit
*APC LD amplifier output pin {OC voltage: PO open in N-sub mode)
©
Tracking error amplifier
ABCLD
;
ne
:
I
1
\
Features
©
Defect detector circuit
LO: amnpliber input. pin-ADe
volage,
Open
©
Operates on a signal - 5 V power supply, as well as on a
©
APC circuit
RF |-V amplifier (1) inverted input pin
+5 V dual-voltage power supply
©
EFM comparator
Current input by connecting to the photodiode A + C terminal
*
Low
power
consumption
(100 mW
with
+5 V, 50 mW
*
Auto asymmetry control amplifier
RF 1-V amplifier (2) inverted input pin
with
+5 V}
Current input by connecting to the photodiode B+ D terminal
*
An APC circuit which accepts esther a P-sub or N-sub laser
Connected to GND when using a positive | + )/negative {~) dual-voltage power supply
diode
Connected to VR (pin 14) when using a single-voltage power supply
¢
A minimum of external parts required
FI-V amplifier inverted input pin
¢
A disc defect detector circuit for improved playability
Current input by connecting to the photodiode F termina!
E 1-V amplifier inverted input pin
Current input by connecting to the photodiode E termina!
E 1-V amplifier output pin
6-1. Block diagram
E I-V amplifier feedback input pin. For E I-V amplifier gain adjustment
DC voitage output pin of (Ver + VeeH2
Input pin for the C-coupled signai output from the defect bottom hold
Defect bottom hold output pin
Connected to the negative power supply when using a positive | + }/negative (—} dual-voltage
power supply.
Connected to GND when using a singie-voliage Dower supply
Bias pin on the focus error amplifier non-inverted
side
For CMR adjustment of the focus error ampiifier
AUTO
ASYMMETRY
Focus error amplifier output pin
Tracking error amplifier Output pin
FOoK
amp
IDIFFEREN—
TAL
AMP.
T
DEFECT
Defect comparator output pin
(DC voltage
connected to a 10 k-ohm load}
MIRR
Mirror comparator
output
pin
{DC voltage:
connected
to a 10 k-onm
load)
Voltage
Reference
Mirror hold capacitor output pin
Mirror comparator non-inverted input
BOTTOM
HOLD
TRACKING
ERROR
amp
Detect bottom hold capacitor connect pin
Connected to GND when using a positive { + l/negative {~} dual-voltage power supply
Connected to GND (Vee) when using a single-voltage power supply
Auto asymmetry
control
input pin
Vernn
—£FM comparator output pin
{DC voltage'
connected to a 10 k-ohm load)
Vion:
FOK comparator output pin.
(DC voltage'
connected to a 10 k-ohm load)
RF tev
AMPLY)
-2.5
LD ON/OFF select pin. (DC voltage:
when LD ON)
{OGND)
_j—____.
2:5:
Positive power supply
"APC: Automatic Power Control
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