Micrel
5V/3.3V 155Mbps
LASER DIODE DRIVER
WITH OUTPUT ENABLE
DESCRIPTION
SY88822V
SY88822V
FEATURES
s
Single 3.3V or 5V power supply
s
Up to 155Mbps operation
s
Modulation current to 30mA
s
PECL output enable
s
Differential PECL inputs
s
Available in a tiny 10-pin (3mm) MSOP
The SY88822V is a high speed current switch for driving
a semiconductor laser diode in optical transmission
applications. The modulation current (I
OUT
) is controlled by
the current (I
RSET
) through the external resistor R
SET
. The
output OUT is HIGH and no current flows through OUT
when output enable is HIGH.
The device incorporates complementary open collector
outputs with a 30mA maximum current driving capability.
The external resistor R
EXT
must be placed between /OUT
and V
CC
to dissipate the worst case power. R
SER
is
recommended to compensate for laser diode matching
issues. Pin 9 and pin 10 should be connected to achieve
better performance.
The SY88822V utilizes the high performance bipolar
ASSET鈩?technology.
APPLICATIONS
s
155Mbps SONET
FUNCTIONAL BLOCK DIAGRAM
V
CC
R
EXT
/OUT
OUT
R
SER
DIN
/DIN
Internal
Logic
to Laser Diode
I
MOD
/EN
40X
V
CC
GND
GND
V
REF
R
SET
R
SET
ASSET is a trademark of Micrel, Inc.
Rev.: A
Amendment: /0
1
Issue Date: March 2003
1
2
3
4
5
