SY88345BL_10 Datasheet, PDF (1/10 Pages) Micrel Semiconductor – 3.3V, 3.2Gbps CML Low-Power Limiting Post

SY88345BL
3.3V, 3.2Gbps CML Low-Power Limiting Post
Amplifier w/ High-Gain TTL Signal Detect
General Description
The SY88345BL high-sensitivity limiting post amplifier is
designed for use in fiber-optic receivers. The device
connects to typical transimpedance amplifiers (TIAs).
The linear signal output from TIAs can contain
significant amounts of noise and may vary in amplitude
over time. The SY88345BL quantizes these signals and
outputs CML-level waveforms.
The SY88345BL operates from a single +3.3V +10%
power supply, and over temperatures ranging from
–40^oC to +85^oC. With its wide bandwidth, high gain, and
signals with data rates up to 3.2Gbps and as small as
5mV_PP can be amplified to drive devices with CML inputs
or AC-coupled CML/PECL inputs.
The SY88345BL generates a signal-detect (SD) open-
collector TTL output. A programmable signal-detect
level-set pin (SD_LVL) sets the sensitivity of the input
amplitude detection. SD asserts high if the input
amplitude rises above the threshold sets by SD_LVL and
de-asserts low otherwise. The enable input (EN) de-
asserts the true output signal without removing the input
signal. The SD output can be fed back to the EN input to
maintain output stability under loss-of-signal condition.
Typically, 3.5dB SD hysteresis is provided to prevent
chattering.
Datasheet and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Features
• Single 3.3V power supply
• 155Mbps to 3.2Gbps operation
• Low-noise CML data outputs
• Chatter-free Open-Collector TTL signal detect (SD)
output with internal 4.75kΩ pull-up resistor
• TTL EN input
• Internal 50Ω input termination
• Programmable SD level set (SD_LVL)
• Ideal for multi-rate applications
• Available in a tiny 10-pin EPAD MSOP and 16-pin
QFN package
Applications
• APON/BPON, EPON, GPON and GEPON
• Gigabit Ethernet
• 1X and 2X Fibre Channel
• SONET/SDH: OC-3/12/24/48–STMD/4/8/16
• High-gain line driver and line receiver
Markets
• FTTP/FTTH
• Optical transceivers
• Datacom/Telecom
• Low-gain TIA interface
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
February 2007
M9999-021207-B
[e-mail] or [phone]