The SY88905 is an integrated Laser Diode controller for
the SY88902 Laser Driver and SY88903 Laser Receiver
that provides power control functions for a complete module
solution. The SY88905 is designed to provide the laser
diode with an independent DC threshold current (I
BIAS
)
source to assure optimum laser diode performance. The
SY88905 also provides buffered Loss-of-Signal (LOS) output
in PECL level. The device is designed for fast and accurate
calibration of the laser diode.
Once the optimal operating point is determined and set
for a specific laser diode, the threshold current (I
BIAS
) is
designed to automatically compensate for laser diode aging
and module temperature.
APPLICATIONS
s
s
s
s
Controller for High Speed Optical Data Transmission
1.25Gbps Gigabit Ethernet
531 Mbps and 1062Mbps Fibre Channel
622Mbps SONET
s
Gigabit Interface Converter
BLOCK DIAGRAM
LOS
OUT
V
REF2
I
BIAS
MD
LOS
IN
40X
V
CC
GND
-
+
V
REF 2
V
REF
I
BIAS SET
I
BIAS FB
I
PIN
SET
M9999-081005
hbwhelp@micrel.com or (408) 955-1690
Rev.: C
Amendment: /0
1
Issue Date: August 2005
Micrel, Inc.
SY88905
PACKAGE/ORDERING INFORMATION
Ordering Information
LOS
IN
1
LOS
OUT
2
GND 3
I
BIAS
4
V
CC
5
MSOP
K10-1
10 V
REF
9 I
BIAS SET
8 I
BIAS FB
7
6
I
PIN SET
MD
Part Number
SY88905KC
SY88905KCTR
(1)
SY88905KH
SY88905KHTR
(1)
Note:
1.
Tape and Reel.
Package
Type
K10-1
K10-1
K10-1
K10-1
Operating
Range
Commercial
Commercial
Commercial
Commercial
Package
Marking
905
905
905 with
Pb-Free bar-line indicator
905 with
Pb-Free bar-line indicator
Lead
Finish
Sn-Pb
Sn-Pb
Pb-Free
NiPdAu
Pb-Free
NiPdAu
10-Pin MSOP (K10-1)
PIN NAMES
Pin
V
CC
GND
LOS
IN
V
REF
I
PIN SET
LOS
OUT
I
BIASFB
I
BIASSET
MD
I
BIAS
Type
Power
Power
TTL Input
Analog Output
Analog Input
PECL Output
Analog Output
Analog Input
Analog Input
Analog Input
Positive Power supply
Ground
Loss-of-Signal Input from SY88903
Reference Voltage
Adjustable, Resistor to V
REF
sets Monitor Diode Photo Current Reference
Loss-of-Signal PECL output
Monitor Diode Feedback
Adjustable, Resistor to V
REF
sets the DC bias current for the Laser Diode
Monitor Diode Connection
DC bias current for the Laser Diode
Description
M9999-081005
hbwhelp@micrel.com or (408) 955-1690
2
Micrel, Inc.
SY88905
ABSOLUTE MAXIMUM RATINGS
(1)
LOGIC DIAGRAM
Symbol
V
CC
LOS
IN
LOS
OUT,
I
PIN SET
I
BIASFB,
I
BIAS SET
T
A
T
store
I
PIN SET,
I
BIAS SET,
I
MD
I
BIASFB
I
BIAS
I
VREF
Rating
Power Supply Voltage
Input Voltage
Others; I/O Voltage
Operating Temperature Range
Storage Temperature Range
Max. Sink Current
Max. Source Current
Max. Sink Current
Max. Source Current
Value
0 to +7.0
0 to V
CC
–0.3, V
CC
+0.3
0 to +85
–55 to +125
1
1
30
2
Unit
V
V
V
˚C
˚C
mA
mA
mA
mA
Note:
1. Permanent device damage may occur if absolute maximum ratings are exceeded. This is a stress rating only and functional operation is not implied at
conditions other than those detailed in the operational sections of this data sheet. Exposure to absolute maximum ratlng conditions for extended periods
may affect device reliability.
100H ECL DC ELECTRICAL
(1)
V
CC
= +5V
±10%
T
A
= 0
°
C
Symbol
V
OH
V
OL
Parameter
Output HIGH Voltage
Output LOW Voltage
Min.
Max.
T
A
= +25
°
C
Min.
Max.
T
A
= +85
°
C
Min.
Max.
Unit
mV
mV
Condition
50Ω to V
CC
–2V
50Ω to V
CC
–2V
V
CC
– 1025 V
CC
– 880 V
CC
– 1025 V
CC
– 880 V
CC
– 1025 V
CC
– 880
V
CC
–1810 V
CC
–1620 V
CC
–1810 V
CC
–1620 V
CC
–1810 V
CC
–1620
Note:
1. 100H circuits are designed to meet the DC specifications shown in the table where transverse airflow greater than 500lfpm is maintained.
M9999-081005
hbwhelp@micrel.com or (408) 955-1690
3
Micrel, Inc.
SY88905
DC ELECTRICAL CHARACTERISTICS
V
CC
= +5V
±10%
T
A
= 0
°
C
Symbol
I
CC
I
BIAS SET
I
BIAS
A
BIAS
V
REF
∆V
PIN SET
∆V
BIAS SET
I
BIAS FB
A
BIAS FB
Notes:
1.
|
I
MD –
I
PIN SET
| =
100µA
2.
|
I
BIAS FB
| / |
I
MD
– I
PIN SET
|
T
A
= +25
°
C
Min.
—
—
0.5
28
2.30
0.95
0.8
0.1
350
4
Typ.
28
—
—
37
2.75
1.13
1.0
0.4
500
—
Max.
40
0.9
25
44
3.30
1.35
1.20
1.0
—
14
40
0.9
25
44
3.30
1.35
1.20
1.0
—
14
T
A
= +85
°
C
Min. Typ. Max. Unit
—
—
0.5
28
2.30
0.95
0.8
0.1
350
4
—
—
—
—
—
—
—
—
—
—
40
0.9
25
44
3.30
1.35
1.20
1.0
—
14
V
V
V
V
µA
mA
mA
mA
=I
BIAS
/ I
BIAS SET
I
REF
= -100µA
=V
REF
– V
PIN SET
=V
REF
– V
BIAS SET
I
BIAS
= 15mA
Conditions
No output load
Parameter
Power Supply Current
I
BIAS SET
Input Current
I
BIAS
Output Current
I
BIAS
Current Gain
Reference Voltage
V
PIN SET
Voltage Tracking
V
BIAS
Voltage Tracking
Feedback Current
(1)
Feedback Gain
(2)
Min.
—
—
0.5
28
2.30
0.95
0.8
0.1
350
4
Typ.
—
—
—
—
—
—
—
—
—
—
Max.
V
COMP BIAS
Compliance Voltage
TTL DC ELECTRICAL CHARACTERISTICS
V
CC
= +5V
±10%
T
A
= 0
°
C
Symbol
V
IH
V
IL
I
IH
I
IL
V
IK
Parameter
Input HIGH Voltage
Input LOW Voltage
Input HIGH Current
Input LOW Current
Input Clamp Voltage
Min.
2.0
—
—
—
—
—
Max.
—
0.8
20
100
–0.3
–1.2
T
A
= +25
°
C
Min.
2.0
—
—
—
—
—
Max.
—
0.8
20
100
–0.3
–1.2
T
A
= +85
°
C
Min.
2.0
—
—
—
—
—
Max.
—
0.8
20
100
–0.3
–1.2
Unit
V
V
µA
mA
V
Condition
—
—
V
IN
= 2.7V
V
IN
= V
CC
V
IN
= 0.5V
I
IN
= –12mA
Note:
1. Individual product specifications over-ride general specifications.
DETAILED DESCRIPTION
The SY88905 is an integrated control circuit for laser
diode modules intended for high-frequency fiber-optic
applications. The device is designed to operate with the
SY88902 laser diode driver providing Automatic Power
Control (APC) which provides bias current control and
monitor diode interface. The device also interfaces with the
