TDA1302_1
14 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
Application of other mechanisms
The TDA1302T can accommodate all laser/monitor
configurations with an N sub-laser diode. When an N
sub-monitor diode is used, external circuitry is required as
illustrated in Figs 11(a) to 11(d). Most of these
laser/monitor diode units have a variable resistor (R
m
) in
parallel with the monitor diode which has been
pre-adjusted so that the voltage drop across this resistor
has a specific value at nominal laser diode output power.
The four circuits given each detail specific values for some
frequently used pick-up units as given in Table 3. Each
circuit has its own advantages. All circuits illustrated make
use of the fixed voltage (<200 mV) across the built-in
monitor resistor.
Table 3
Pick-up units.
PICK-UP
UNIT
SLD104U
LT022MS
RLD-78MA
MANUFACTURER
Sony corporation
Sharp corporation
Rohm corporation
TDA1302T
APPLICATION
KSM210 (Sony)
KSM210 (Sony)
KSM210 (Sony)
HOP-M3TR
(Hitachi)
SF91
Sony corporation
CDV90V1 (Sanyo)
Fig.11 Applications of the laser/monitor units.
September 1994
14
PHILIPS [ NXP SEMICONDUCTORS ]
