tza1020 NXP Semiconductors, tza1020 Datasheet - Page 29

• Manufacturer Part Number: tza1020
• Description: Pre-amplifiers For Cd-rw Systems
• Manufacturer: NXP Semiconductors

Philips Semiconductors
11.2
The alpha circuit can be split into an alpha circuit for CD-RW, an alpha circuit for CD-R and a subtractor with additional
gain switching. The alpha circuit is active only if AMON = 1.
Table 31 Alpha scale factors
Table 32 Alpha currents; note 1
Note
1. The currents and gain factor are proportional to I
2000 Oct 30
gain input current
current gain output
subtractor gain
I
I
alphagain
ref
Pre-amplifiers for CD-RW systems
ALPHA CIRCUIT
SCALE FACTOR
Laser power control signals (alpha circuit)
CURRENTS
alphagain4 to alphagain0
alphactrl2 to alphactrl0
CONTROL SIGNAL
CONTROL SIGNAL
algctrl4 and Algctrl6
algctrl1 and algctrl0
RREF
. The given current values are valid at I
29
CONTROL SIGNAL
CONTROL SIGNAL
BINARY VALUE
BINARY VALUE
00000
01111
11111
001
010
011
100
101
110
111
000
00
01
10
11
00
01
10
11
TZA1020; TZA1020A
VALUE SCALE FACTOR
VALUE CURRENT ( A)
RREF
Product specification
3.125
= 900 A.
0.50
0.33
0.25
0.20
0.17
0.14
0.12
0.11
0.25
0.75
100
0.5
1.0
50
20
0
1
3
4