Data Sheet
February 1999
LG1605DXB Limiting Amplifier
Features
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s
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s
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Digital video transmission
Interface between 1319 receiver and LG1600
clock and data regenerator
High-speed comparator
28 dB gain, 34 dB differential
Large dynamic range: >60 dB
Wideband response: 8 kHz to 3 GHz
Extremely low ±4 ps delay skew across input range
Complementary 50
Ω
I/Os
Surface-mount package
Standard ECL supply (400 mW)
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Functional Description
The LG1605DXB is a GaAs wideband limiting ampli-
fier with differential inputs and outputs that provides
28 dB of gain (34 dB differential) and 3 GHz of band-
width in a 50
Ω
environment (Figure 1 shows the
block diagram). At low input levels, below 10 mV to
20 mV, the circuit behaves as a linear amplifier. At
higher levels, the device goes smoothly into limiting.
The device matches the performance of an AGC
amplifier but shows none of the AGC bouncing and
attack characteristics.
V
SS
7
GND
1, 4, 5, 6, 15, 16
Applications
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Data/clock main amplifier SONET/SDH OC-48/
STM-16 transmission systems, DWDM systems
V
BR
8
110 pF
110 pF
V
–REF
V
–IN
V
+IN
V
+REF
110 pF
–
9
10
11
12
50
Ω
25 kΩ
+
50
Ω
+ –
– +
+ –
– +
25 kΩ
CHIP BOUNDARY
3
2
V
–OUT
V
+OUT
13
V
BF
14
V
BS
12-3214(F).r3
Figure 1. LG1605DXB Block Diagram
AGERE [ AGERE SYSTEMS ]
