TDA1302_1
2 Wed Sep 14 13:30:56 1994
Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for
CD player and read only optical systems
FEATURES
•
Six input buffer amplifiers with low-pass filtering and with
virtually no offset
•
HF data amplifier with a high or low gain mode
•
Two built-in equalizers for single or double-speed mode
ensuring high performance in both modes
•
Fully automatic laser control including stabilization and
an ON/OFF switch, plus a separate supply (V
DDL
) for
power reduction
•
Adjustable laser bandwidth and laser switch-on current
slope
•
Protection circuit to prevent laser damage due to supply
voltage dip
•
Optimized interconnectiion between pick-up detector
and digital servo processor (TDA1301T)
•
Wide supply voltage range
•
Wide temperature range
•
Low power consumption.
QUICK REFERENCE DATA
SYMBOL
V
DD
G
dn
I
os(d)
B
PARAMETER
supply voltage (pin 18)
CONDITIONS
MIN.
3.4
−
−
I
i(d)
= 1.67
µA
f
i
= 0.3 MHz
double-speed
50
−
−
−
−
TYP.
GENERAL DESCRIPTION
TDA1302T
The TDA1302T is a data amplifier and laser supply circuit
for three-beam pick-up detectors applied in a wide range
of mechanisms for Compact Disc and read only optical
systems. The device contains 6 amplifiers which amplify
and filter the focus and radial diode signals and provides
an equalized RF signal suitable for single or double speed
mode; the mode can be switched by means of the speed
control pin. The device can accommodate astigmatic,
single foucault and double foucault detectors and can be
applied to all N-sub laser/monitor diode units even though
the circuit has been optimized for the Philips CDM12
mechanisms and the digital servo controller TDA1301T.
After a single initial adjustment the circuit will maintain
control over the laser diode current thus resulting in a
constant light output power which is independent of
ageing. The IC is mounted in a small-outline package to
enable it to be mounted close to the laser pick-up unit on
the sledge.
MAX.
5.5
−
100
−
−
−
−100
V
UNIT
Diode current amplifiers
amplification
diode output offset current
3 dB bandwidth
1.55
−
−
dB
nA
kHz
RFE amplifier (built-in equalizer)
t
d(eq)
t
d(f)
Laser supply
I
o(l)
output current
V
DDL
= 3 V
−
mA
equalization delay
flatness delay
320
5
ns
ns
ORDERING INFORMATION
PACKAGE
TYPE NUMBER
NAME
TDA1302T
SO24
DESCRIPTION
plastic small outline package; 24 leads; body width 7.5 mm
VERSION
SOT137-1
September 1994
2
PHILIPS [ NXP SEMICONDUCTORS ]
