MAX3761 Datasheet, PDF (1/12 Pages) Maxim Integrated Products – Low-Power, 622Mbps Limiting Amplifiers with Chatter-Free Power Detect for LANs

19-1097; Rev 3; 7/04
EVAALVUAAILTAIOBNLEKIT
Low-Power, 622Mbps Limiting Amplifiers
with Chatter-Free Power Detect for LANs
_______________General Description
The MAX3761/MAX3762 limiting amplifiers, with 4mV
sensitivity and PECL data outputs, are optimized for
operation in low-cost, 622Mbps, LAN/ATM LAN fiber
optics applications.
An integrated power detector senses the input signal’s
amplitude. A received-signal-strength indicator (RSSI)
gives an analog indication of the power level, while the
complementary loss-of-signal (LOS) outputs indicate if
the input power level exceeds the programmed
threshold level. The LOS threshold can be adjusted to
detect signal amplitudes between 3mVp-p and
100mVp-p, providing a 15dB LOS adjustment in fiber
optic receivers. The LOS outputs have 3.5dB of
hysteresis, which prevents chatter when input signal
levels are small. The MAX3761’s LOS outputs are com-
patible with TTL-logic levels. The MAX3762 has PECL
LOS outputs.
DISABLE and LOS can be used to implement a squelch
function, which turns off the data outputs when the
input signal is below the programmed threshold.
________________________Applications
622Mbps LAN/ATM LAN Receivers
155Mbps LAN/ATM LAN Receivers
____________________________Features
o Chatter-Free Power Detector with Programmable
Loss-of-Signal Outputs
o 4mV Input Sensitivity (PECL Loss-of-Signal
Interface Logic—MAX3766
o PECL Data Outputs
o Single 5V Power Supply
o 250ps Output Edge Speed
o Low 15ps Pulse-Width Distortion
o TTL Loss-of-Signal Interface Logic—MAX3761
Ordering Information
PART
MAX3761EEP
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
20 QSOP
MAX3761C/D
MAX3762EEP
MAX3762EEP+
MAX3762C/D
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
Dice*
20 QSOP
20 QSOP
Dice*
*Dice are designed to operate from -40°C to +85°C, but are
tested and guaranteed only at T_A = +25°C.
+Denotes lead free package.
__________________Pin Configuration _________Typical Operating Circuits
TOP VIEW
FILTER ₁
RSSI ₂
EN ₃
V_{CC 4}
VIN+ ₅
VIN- ₆
GND ₇
SUB ₈
CZP ₉
CZN ₁₀
MAX3761
MAX3762
20 ^DISABLE
19 LOS+
18 ^LOS-
17 VCC
16 VCCO
15 OUT+
14 OUT-
13 GNDO
12 VTH
11 INV
QSOP
+5V
100pF
BYPASS
SUPPLY
10nF
C_IN
5.6nF
C_IN
5.6nF
100pF
C_FILTER
+V_CC
V_CC
EN
RSSI
VCCO
VIN+
CZP
CZN
DISABLE
LOS+
LOS-
OUT-
OUT+
MAX3761
VIN-
GNDO
FILTER
GND
INV
SUB
VTH
C_AZ
150pF
50Ω
50Ω
V_CC - 2V
R1
100kΩ
R2
22kΩ
MAX3762 at end of data sheet.
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.