SY88923AV Datasheet, PDF (1/8 Pages) Micrel Semiconductor – 5V/3.3V 3.2Gbps HIGH-SPEED LIMITING POST AMPLIFIER

Micrel, Inc.
5V/3.3V 3.2Gbps HIGH-SPEED
LIMITING POST AMPLIFIER
SY88923AV
SY88923AV
FEATURES
s Single 3.3V or 5V power supply
s Up to 3.2Gbps operation
s Low noise PECL data outputs
s Chatter-free open collector TTL LOS output
s TTL /EN Input
s Differential PECL inputs for data
s Available in a tiny 10-pin (3mm) MSOP and 10-pin
(3mm) EPAD-MSOP
APPLICATIONS
s 1.25Gbps and 2.5Gbps Gigabit Ethernet
s 531Mbps, 1062Mbps and 2.12Gbps Fibre Channel
s 622Mbps SONET
s Gigabit interface converter
s 2.5Gbps SDH/SONET
s 2.5Gbps proprietary links
s Parallel 10G Ethernet
DESCRIPTION
The SY88923AV limiting post amplifier with its high
gain and wide bandwidth is ideal for use as a post
amplifier in fiber-optic receivers with data rates up to
3.2Gbps. Signals as small as 5mV_PP can be amplified
to drive devices with PECL inputs. The SY88923AV
generates a chatter-free Loss-of-Signal (LOS) open
collector TTL output.
The SY88923AV incorporates a programmable level
detect function to identify when the input signal has been
lost. The LOS output will change from logic “LOW” to logic
“HIGH” when input signal is smaller than the swing set by
LOS_LVL. This information can be fed back to the EN input
of the device to maintain stability under loss-of-signal
condition. Using LOS_LVL pin, the sensitivity of the level
detection can be adjusted. The LOS_LVL voltage can be set
by connecting a resistor divider between V_CC and V_REF
shown in Figure 3. “Typical Operating Characteristics” on
page 6 show the relationship between input level sensitivity
and the voltage set on LOS_LVL.
The LOS output is a TTL open collector output that
requires a pull-up resistor for proper operation, Figure 1.
SY88923AV
LOS
V_CC
4.7kΩ to 10kΩ
BLOCK DIAGRAM
D_IN
/D_IN
V_REF
V_CC
GND
Limiting
Amplifer
LOS_LVL
M9999-110905
[e-mail] or [phone]
Figure 1. LOS Output with Desired Rise Time
ECL
Buffer
Enable
D_OUT
/D_OUT
/EN
Level
Detect
LOS
1
Rev.: F Amendment: /0
Issue Date: November 2005