Document
Micrel
5V 622Mbps LASER DIODE DRIVER WITH OUTPUT ENABLE
SY88702
SY88702
FEATURES
s s s s s s Up to 622Mbps operation Modulation current to 25mA PECL output enable Differential PECL inputs Single 5V power supply Available in a tiny 10-pin (3mm) MSOP
DESCRIPTION
The SY88702 is a high-speed current switch for driving a semiconductor laser diode in optical transmission applications. The modulation current (IOUT) is controlled by the current (IRSET) through the external resistor RSET. The output OUT is HIGH and no current flows through OUT when output enable is HIGH. The device incorporates complementary open collector outputs with 25mA maximum current driving capability. The external resistor R EXT must be placed between /OUT and VCC to dissipate the worst case power. RSER is recommended to compensate for laser diode matching issues. The SY88702 utilizes the high performance bipolar ASSET™ technology.
APPLICATIONS
s 622Mbps SONET
www.DataSheet4U.com
FUNCTIONAL BLOCK DIAGRAM
VCC REXT /OUT OUT RSER DIN /DIN Internal Logic /EN 40X VCC GND VEE VREF RSET IMOD to Laser Diode
RSET
ASSET is a trademark of Micrel, Inc.
Rev.: B Amendment: /0
1
Issue Date: August 2003
Micrel
SY88702
PACKAGE/ORDERING INFORMATION
Ordering Information
/EN 1 DIN 2 /DIN 3 VREF 4 RSET 5 10 VCC 9 OUT 8 /OUT 7 GND 6 GND
Part Number SY88702KC SY88702KCTR* SY88702KI SY88702KITR*
*Tape and Reel
Package Type K10-1 K10-1 K10-1 K10-1
Operating Range Commercial Commercial Industrial Industrial
Package Marking 702 702 702 702
10-Pin MSOP (K10-1)
PIN DESCRIPTION
Pin Number 1 2, 3 4 5 6, 7 9, 8 10 Pin Name /EN DIN, /DIN VREF RSET GND OUT, /OUT VCC Pin Function 100k PECL compatible input with 75kΩ pull-down resistor. Modulation current goes to zero when deasserted high. Differential 100k PECL compatible input with 75kΩ pull-down resistors. Voltage reference for use with RSET. An external resistor connected from here to VREF sets the reference current for IOUT. Device ground. Differential open collector current outputs. Positive power supply.
TRUTH TABLE(1)
D L H X /D H L X /EN L L H OUT (2) H L H /OUT L H L
Note 1. L = LOW, H = HIGH, X = don't care. Note 2. H = IOUT = 0mA.
2
Micrel
SY88702
Absolute Maximum Ratings(Note 1)
Power Supply Voltage (VCC) ............................ 0V to +7.0V Input Voltage (VIN) .............................................. 0V to VCC Output Current (IOUT) ................................................. 25mA Power Dissipation (PD) ........................................... 250mW Storage Temperature Range (TS) ............ –55°C to +125°C
Operating Ratings(Notes 2,3,4)
Supply Voltage (VCC) .................................. +4.5V to +5.5V Ambient Temperature (TA), Note 5 ............ –40°C to +85°C Junction Temperature (TJ), Note 5 ............ –40°C to 100°C Resistor to Dissipate Power (REXT) .................. 10Ω to 50Ω Laser Diode Serial Resistor (RSER) .................... 0Ω to 50Ω Resistor to Adjust Current (RSET) .......... 150.