SY88952L Datasheet, PDF (1/7 Pages) Micrel Semiconductor – 3.3V, 2.7Gbps SDH/SONET LASER DRIVER WITH AUTOMATIC POWER CONTROL

Micrel, Inc.
3.3V, 2.7Gbps SDH/SONET
LASER DRIVER WITH AUTOMATIC
POWER CONTROL
SY88952L
SY88952L
FEATURES
s Single 3.3V power supply
s Up to 2.7Gbps operation
s Rise/Fall times: < 75ps
s Independent programmable laser modulation and
bias currents
s Bias current to 100mA and modulation current to
90mA
s Automatic average laser power control
s Bias and modulation current monitors
s Operating temperature range of –40°C to +85°C
s Complies with ANSI, ITU, and Bellcore SDH/SONET
specifications
s Available in DIE form and 32-pin (5mm × 5mm)
EPAD-MLF™ package
APPLICATIONS
s OC-48 transceivers and transponders
s SONET/SDH transmission system
s Add drop mux
s Metro area network
s 2.5Gbps optical transmitter
s Fiber optical module
DESCRIPTION
SY88952L is a highly integrated and programmable
laser driver for SONET/SDH application up to 2.7Gbps.
The device accepts differential PECL or LVDS data and
clock inputs. It provides programmable bias and
modulation currents for driving a laser. The modulation
output of SY88952L can be DC-coupled to drive the laser
diode, providing a significant power saving over AC-
coupled operation. A synchronizing TTL input latch can
be used to reduce jitter if a clock signal is available. A
TTL enable is also incorporated in the device. EN only
enables/disables I_MOD. It does not enable/disable I_BIAS.
An automatic power controller (APC) is integrated into
SY88952L to maintain a constant average optical output
power over temperature and lifetime. The modulation
current can be externally temperature compensated to
minimize the variation of extinction ratio of the optical
output.
Several safety features will enable an alarm function
when the output signal is too high, or bias current is too
high.
There are two alarm conditions:
1. /FAIL asserts when bias current loop goes to
maximum of it's range. I_BIAS and I_MOD still flow under
this condition.
2. /FAIL asserts when I_BIASMAX or I_MODSET are too
high (implying I_BIAS or I_MOD will be too high). All currents
will shut off under this condition.
MLF and MicroLeadFrame are trademarks of Amkor Technology, Inc.
M9999-082205
[e-mail] or [phone]
1
Rev.: B Amendment: /0
Issue Date: August 2005