Global Mixed-mode Technology Inc.
G569C
CD-RW Laser Diode Current Driver
Features
Single +5V supply
Laser diode read current driver
Laser diode write current driver
Laser diode Erase current driver
Deltap circuit to control write current
FSA circuit to integrate photo diode current
Cagain circuit to convert V
cagain
into current
Dalpha circuit to perform voltage subtraction
and limiting
3-wire interface to control internal DAC
A build-in OP-AMP
48-pin SSOP package
General Description
The G569C is a single chip solution for the various
functions relating to laser diode operation in a CD-RW
drive. The G569C integrates nine functional blocks in
one chip. It has five voltage-to-current converters, one
current-to-voltage converters which is called FSA, one
OP-AMP, one eight-channels D/A converter, and one
voltage subtracter with output clamping capability
called Dalpha.
Three of the five V-to-I converters provide the laser
diode currents for Read, Write, and Erase operations,
respectively; another one of the V-I converters
provides the Cagain current; and the other one
provides Deltap current which can selectively shunt a
certain amount of laser diode current for write
operation. For the Write and Erase operations, the
voltage to current conversion ratio can be adjusted
using an external or internal DAC resistor array. The
FSA circuit performs integration on the output current
of an external photo diode, and sample-and-hold the
peak voltage. It is used to monitor the laser diode
power. The internal eight-channel D/A converter is
used to provide the input voltage for above functional
blocks. The G569C is available in a 48-pin SSOP
surface-mount package.
Applications
CD-RW Drive
Pin configuration
G569C
IW_IN
LS_DELTA
TST1
PWO
DALPHA
PWO_I
PWB
PWMAX
PWMIN
/RESET
VSS
EDB
LS_ERASE
PERASE
RECORD
CDR
S2V9
CAGAIN2
CAGS_I
DCAGAIN
CAGAIN
RCAGAIN1
RCAGAIN2
PRFINE
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
WDB
LS_WRITE
PWRITE
LD
DI
CLK
VSS
VOUT
VI-
VI+
VDD
FSOF
FSWS
FSCLR
FSW
IFSA
FSR
FSRS
VDD
SELN4_IN
PR_I
LS_READ
IR
PRCOARSE
Ordering Information
ORDER ORDER NUMBER
NUMBER
(Pb free)
G569CS8U
G569CS8Uf
Note: S8: SSOP-48
U: Tape & Reel
TEMP.
RANGE
0°C to 85°C
PACKAGE
SSOP-48
SSOP-48
Ver: 1.0
Oct 02, 2000
TEL: 886-3-5788833
http://www.gmt.com.tw
1
GMT [ GLOBAL MIXED-MODE TECHNOLOGY INC ]
