Philips Semiconductors
Data amplifier and laser supply circuit for CD
audio and video optical systems (ADALASLC)
Product specification
TZA1025
The application for the TZA1025 (ADALASLC) with the SAA7325 (CD10LC) without a coupling capacitor is shown in
Fig.7. A minimum supply voltage (VDD) is required for optimal performance.
handbook, full pagewidth
VDD(LASER)
VDD(5)
from
microprocessor(2)
LD
MON
VCOM
LD
1
100 nF
VDD(L)
2
10 nF CFIL
3
RGADJ RRGADJ(1)
14
VDD
13
GND
12
VDD
MON 4 (ATDZAAL1A0S2L5C)11 CDRW
DIN
RFEQO
5
10
GND
6
PWRON
7
RFFB
9
CMFB
8
10 kΩ(3)
100 nF
1 kΩ
47 pF
HFIN
HFREF
OPU
C2(4)
100 nF
ISLICE
100 nF
LDON
VRIN
SAA7325
(CD10LC)
R2 (4×)
D1
D1
D2
D2
D3
D3
D4
D4
S1
S1
S2
S2
LF FILTER
6 × 220 pF
MBK904
(1) See equation (3) to calculate the value of this resistor.
(2) Pin CDRW can be controlled by the CD10LC or a microprocessor but can also be fixed or switched by any other means.
(3) The 10 kΩ feedback resistor between pins 9 and 10 is a fixed value.
(4) The high-pass filter (AC-coupling) is placed at the input of the preamplifier. The −3 dB point (f = 10 kHz) is at -R----2-----(---Ω-----)----4×-----C-----2----(---F----)-
(5) The minimum supply voltage (VDD) without using a coupling capacitor is 2.8 V.
Fig.7 Application diagram with SAA7325 (CD10LC) without coupling capacitor.
1998 Oct 30
11