19-3297; Rev 0; 5/04
155Mbps to 3.2Gbps, Low-Power SFP
Limiting Amplifiers
General Description
The MAX3747/MAX3747A multirate limiting amplifiers
function as data quantizers for OC-3 through OC-48 syn-
chronous optical network (SONET), Fibre-Channel, and
Gigabit Ethernet optical receivers. They are pin-for-pin
compatible with the SY88993V from Micrel
Semiconductor, Inc. The amplifiers accept a wide range
of input voltages and provide constant-level, current-
mode logic (CML) output voltages with controlled edge
speeds. The MAX3747 output voltage level is 500mVp-p
and the MAX3747A output voltage is 800mVp-p.
The MAX3747/MAX3747A limiting amplifiers feature a
programmable loss-of-signal detect (LOS) and an
optional disable function (DISABLE). Output disable can
be used to implement squelch.
The MAX3747/MAX3747A are available in a 3mm, 10-pin
µMAX® package ideal for small form-factor receivers.
♦
155Mbps to 3.2Gbps Operation
♦
>57dB of Gain for the MAX3747 and MAX3747A
♦
<10
-12
BER with 2mV
P-P
Input Amplitude
♦
18mA Supply Current
♦
Chatter-Free LOS with Programmable Threshold
♦
Output DISABLE Function
♦
PECL-Compatible Inputs
Features
♦
Pin Compatible with Micrel SY88993V
MAX3747/MAX3747A
Ordering Information
PART
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-
PACKAGE
10 µMAX
10 µMAX
PKG
CODE
U10C-4
U10C-4
Applications
Gigabit Ethernet SFP/SFF Optical Transceiver
Modules
1G/2G Fibre-Channel SFP/SFF Optical
Transceiver Modules
Multirate OC-3 to OC-48 FEC SFP/SFF Optical
Transceiver Modules
10G LX4 Transceiver Modules
SFP OPTICAL RECEIVER
3-INPUT
DIAGNOSTIC
MONITOR
DS1859
MAX3747EUB
MAX3747AEUB
µMAX is a registered trademark of Maxim Integrated Products, Inc.
Pin Configuration appears at end of data sheet.
Typical Application Circuit
HOST BOARD
SUPPLY FILTER
V
CC
HOST FILTER
V
CC_
RX
MAX4004
V
CC
0.1µF
IN+
MAX3747
MAX3747A
OUT+
0.1µF
50Ω
0.1µF
50Ω
SERDES
MAX3745
0.1µF
IN-
OUT-
5-PIN TO-HEADER
50Ω
50Ω
V
REF
TH
GND LOS
DISABLE
4.7kΩ TO 10kΩ
V
CC_
HOST
R1
0.1µF
R2
0.1µF
LOS
V
CC
R1 + R2
≥
5kΩ
________________________________________________________________
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.
155Mbps to 3.2Gbps, Low-Power SFP
Limiting Amplifiers
MAX3747/MAX3747A
ABSOLUTE MAXIMUM RATINGS
Power-Supply Voltage (V
CC
) .................................-0.5V to +4.5V
Voltage at IN+, IN- ..........................(V
CC
- 2.4V) to (V
CC
+ 0.5V)
Voltage at DISABLE, LOS, TH, V
REF
..........-0.5V to (V
CC
+ 0.5V)
Current into LOS ...................................................-1mA to +9mA
Current into V
REF
..................................................................2mA
Differential Input Voltage (IN+ - IN-) .....................................2.5V
Continuous Current at CML Outputs
(OUT+, OUT-) ..............................................-25mA to +25mA
Continuous Power Dissipation (T
A
= +70°C)
10-Pin µMAX (derate 6.9mW/°C above +70°C) ...........552mW
Operating Junction Temperature Range (TJ) .......-55°C to +150°C
Storage Ambient Temperature Range (TS)...........-55°C to +150°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
CC
= +2.97V to +3.63V, CML output load is 50Ω to V
CC
, T
A
= -40°C to +85°C. Typical values are at V
CC
= +3.3V and T
A
= +25°C,
unless otherwise specified.) (Note 1)
PARAMETER
POWER SUPPLY
MAX3747 includes the CML output current
Supply Current (Note 2)
I
CC
MAX3747A includes the CML output current
MAX3747/MAX3747A exclude the CML
output current
f < 2MHz
(Note 3)
(Note 3)
1200
42
DUT is powered on, f < 3GHz
MAX3747A 4mV
P-P
≤
V
IN
≤
1200mV
P-P
MAX3747 4mV
P-P
≤
V
IN
≤
1200mV
P-P
AC-coupled outputs, V
IN-MAX
applied to the
input (Note 4)
20% to 80% (Note 4)
K28.5 pattern at 3.2Gbps
PRBS 2
23
- 1 equivalent pattern at 2.7Gbps
(Note 6)
Deterministic Jitter (Notes 4, 5)
DJ
K28.5 pattern at 2.1Gbps
PRBS 2
23
- 1 equivalent pattern at 155Mbps
(Note 6)
Random Jitter
Input-Referred Noise
Low-Frequency Cutoff
V
IN
= 4mV
P-P
(Notes 4, 7)
V
IN
= 4mV
P-P
(Note 4)
70
13.2
14
12
85
3.5
120
6.4
600
400
50
15
800
500
1000
600
15
120
19
25
17
150
5
150
ps
RMS
µV
RMS
kHz
ps
P-P
58
30
36
18
30
4
35
41
24
dB
mV
P-P
mV
P-P
Ω
dB
mV
P-P
mV
P-P
ps
mA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Power-Supply Noise Rejection
INPUT SPECIFICATION
Input Sensitivity
Input Overload
OUTPUT SPECIFICATION
Output Resistance
Differential Output Return Loss
CML Differential Output Voltage
Differential Output Signal When
Disabled
Data-Output Transition Time
TRANSFER CHARACTERISTIC
PSNR
V
IN-MIN
V
IN-MAX
R
OUT
2
_______________________________________________________________________________________
155Mbps to 3.2Gbps, Low-Power SFP
Limiting Amplifiers
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +2.97V to +3.63V, CML output load is 50Ω to V
CC
, T
A
= -40°C to +85°C. Typical values are at V
CC
= +3.3V and T
A
= +25°C,
unless otherwise specified.) (Note 1)
PARAMETER
LOSS OF SIGNAL
LOS Hysteresis
LOS-Assert/Deassert Time
Low LOS Assert Level
Low LOS Deassert Level
Medium LOS Assert Level
Medium LOS Deassert Level
High LOS Assert Level
High LOS Deassert Level
TTL/CMOS I/O
V
REF
Voltage
LOS Output High Voltage
LOS Output Low Voltage
DISABLE Input High
DISABLE Input Low
DISABLE Input Current
V
REF
V
OH
V
OL
V
IH
V
IL
R
LOS
= 4.7kΩ to 10kΩ to V
CC_HOST
R
LOS
= 4.7kΩ to 10kΩ to V
CC_HOST
(3V)
R
LOS
= 4.7kΩ to 10kΩ to V
CC_HOST
(3.6V)
2.0
0.8
10
V
CC
-
1.35
2.4
0.4
V
CC
-
1.3V
V
CC
-
1.19
V
V
V
V
V
µA
10log(V
DEASSERT
/ V
ASSERT
) (Note 4)
(Notes 4, 8)
V
TH
= -1.3V (Notes 4, 9)
V
TH
= -1.3V (Notes 4, 9)
V
TH
= -0.68V (Notes 4, 9)
V
TH
= -0.68V (Notes 4, 9)
V
TH
= -0.114V (Notes 4, 9)
V
TH
= -0.114V (Notes 4, 9)
36.0
22
1.25
2.3
2.5
4.1
6.2
29
44.8
53.7
86
40.0
5.9
9.3
31
57
63.6
115
dB
µs
mV
P-P
mV
P-P
mV
P-P
mV
P-P
mV
P-P
mV
P-P
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX3747/MAX3747A
Note 1:
The data-input transition time is controlled by a 4th-order Bessel filter with f
-3dB
= 0.75 x 2.667GHz for all data rates of
2.667Gbps and below. The f
-3db
= 0.75 x 3.2GHz for a data rate of 3.2Gbps.
Note 2:
Supply current is measured with unterminated outputs or with AC-coupled output termination (see Figure 1).
Note 3:
Between sensitivity and overload, all AC specifications are met and the output is 0.95 x limited output amplitude.
Note 4:
Guaranteed by design and characterization.
Note 5:
The deterministic jitter (DJ) caused by the input filter is not included in the DJ generation specification.
Note 6:
The PRBS 2
23
- 1 equivalent pattern consists of a K28.5 pattern plus 240 ones plus K28.5 pattern plus 240 zeros.
Note 7:
Random jitter was measured without using a filter at the input.
Note 8:
The signal at the input is switched between two amplitudes, Signal_ON and Signal_OFF, as shown in Figure 2.
Note 9:
V
TH
is the voltage at pin 5 referenced to V
CC
(see Figure 5).
_______________________________________________________________________________________
3
155Mbps to 3.2Gbps, Low-Power SFP
Limiting Amplifiers
MAX3747/MAX3747A
V
CC
I
CC
(SUPPLY
CURRENT)
I
OUT
(CML OUTPUT
CURRENT)
V
IN
SIGNAL ON
1dB
MAXIMUM DEASSERT LEVEL
50Ω
50Ω
6dB
MAXIMUM POWER-DETECT WINDOW
MINIMUM ASSERT LEVEL
0V
SIGNAL OFF
TIME
MAX3747
MAX3747A
Figure 1. Power-Supply Current Measurement
Figure 2. LOS Deassert Threshold—Set 1dB Below the
Minimum by Receiver Sensitivity
Typical Operating Characteristics
(V
CC
= +3.3V, T
A
= +25°C, unless otherwise noted.)
OUTPUT EYE DIAGRAM
(MINIMUM INPUT)
MAX3747/MAX3747A toc01
OUTPUT EYE DIAGRAM
(MAXIMUM INPUT)
MAX3747/MAX3747A toc02
3.2Gbps, 2
23
- 1 PRBS, 4mV
P-P
3.2Gbps, 2
23
- 1 PRBS, 1200mV
P-P
60mV/div
60mV/div
50ps/div
50ps/div
4
_______________________________________________________________________________________
155Mbps to 3.2Gbps, Low-Power SFP
Limiting Amplifiers
MAX3747/MAX3747A
Typical Operating Characteristics (continued)
(V
CC
= +3.3V, T
A
= +25°C, unless otherwise noted.)
OUTPUT EYE DIAGRAM
(MINIMUM INPUT)
MAX3747/MAX3747A toc03
OUTPUT EYE DIAGRAM
(MAXIMUM INPUT)
MAX3747/MAX3747A toc04
OUTPUT EYE DIAGRAM AT +100
°
C
MAX3747/MAX3747A toc05
2.7Gbps, 2
23
- 1 PRBS, 4mV
P-P
2.7Gbps, 2
23
- 1 PRBS, 1200mV
P-P
2.125Gbps, CJTPAT, 50mV
P-P
60mV/div
60mV/div
60mV/div
70ps/div
70ps/div
80ps/div
SUPPLY CURRENT vs. TEMPERATURE
(EXCLUDES OUTPUT CURRENT)
MAX3747/MAX3747A toc06
TRANSFER FUNCTION
(OUTPUT VOLTAGE vs. INPUT VOLTAGE)
MAX3747/MAX3747A toc07
RANDOM JITTER vs. TEMPERATURE
2.7
2.4
RANDOM JITTER (ps
RMS
)
2.1
1.8
1.5
1.2
0.9
0.6
0.3
0
V
IN
= 50mV
P-P
, FREQ = 2.7Gbps
MAX3747/MAX3747A toc08
50
45
SUPPLY CURRENT (mA)
40
35
30
25
20
15
10
-40 -30 -20 -10 0 10 20 30 40 50 60 70 80
TEMPERATURE (
°
C)
1000
900
DIFFERENTIAL OUTPUT (mV
P-P
)
800
700
600
500
400
300
200
100
0
0
1
2
3
4
5
DIFFERENTIAL INPUT (mV
P-P
)
MAX3747
MAX3747A
3.0
-40 -30 -20 -10 0 10 20 30 40 50 60 70 80
TEMPERATURE (
°
C)
RANDOM JITTER vs. INPUT AMPLITUDE
3.2Gbps
MAX3747/MAX3747A toc09
BIT-ERROR RATIO vs. INPUT VOLTAGE
13,000
12,000
11,000
10,000
9000
8000
7000
6000
5000
4000
3000
2000
1000
1
0
1
MAXIM
MAX3747
MAX3747/MAX3747A toc10
5
4
RANDOM JITTER (ps
RMS
)
3
2
BIT-ERROR RATIO (10
-12
)
1
MICREL
SY88993V
0
1
10
100
1000
10,000
DIFFERENTIAL INPUT AMPLITUDE (mV
P-P
)
2
3
4
5
6
7
8
9
10
DIFFERENTIAL INPUT AMPLITUDE (mV
P-P
)
_______________________________________________________________________________________
5