19-1523; Rev 7, 2/06
+3.0V to +5.5V, 1.25Gbps/2.5Gbps
Limiting Amplifiers
MAX3264/MAX3265/MAX3268/MAX3269/MAX3765/MAX3768
General Description
The 1.25Gbps MAX3264/MAX3268/MAX3768 and the
2.5Gbps MAX3265/MAX3269/MAX3765 limiting ampli-
fiers are designed for Gigabit Ethernet and Fibre
Channel optical receiver systems. The amplifiers accept
a wide range of input voltages and provide constant-
level output voltages with controlled edge speeds.
Additional features include RMS power detectors with
programmable loss-of-signal (LOS) indication, an
optional squelch function that mutes the data output sig-
nal when the input voltage falls below a programmable
threshold, and excellent jitter performance.
The MAX3264/MAX3265/MAX3765 feature current-mode
logic (CML) data outputs that are tolerant of inductive
connectors and a 16-pin TSSOP package, making these
circuits ideal for GBIC receivers. The MAX3268/
MAX3269/MAX3768 feature standards-compliant posi-
tive-referenced emitter-coupled logic (PECL) data out-
puts and are available in a tiny 10-pin µMAX package
that is ideal for small-form-factor (SFF) receivers.
Features
♦
+3.0V to +5.5V Supply Voltage
♦
Low Deterministic Jitter
14ps (MAX3264)
11ps (MAX3265/MAX3765)
♦
150ps (max) Edge Speed (MAX3265/MAX3765)
300ps (max) Edge Speed (MAX3264)
♦
Programmable Signal-Detect Function
♦
Choice of CML or PECL Output Interface
♦
10-Pin µMAX or 16-Pin TSSOP Package
Ordering Information
PART
MAX3264CUE
MAX3264CUE+
MAX3264C/D
MAX3265CUE
MAX3265CUE+
MAX3265CUB
MAX3265CUB+
MAX3265EUE
MAX3265EUE+
MAX3265C/D
TEMP RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
PIN-PACKAGE
16 TSSOP-EP*
16 TSSOP-EP*
Dice**
16 TSSOP-EP*
16 TSSOP-EP*
10 µMAX-EP*
10 µMAX-EP*
16 TSSOP-EP*
16 TSSOP-EP*
Dice**
Applications
Gigabit Ethernet Optical Receivers
Fibre Channel Optical Receivers
System Interconnect
ATM Optical Receivers
Selector Guide appears at end of data sheet.
Pin Configurations appear at end of data sheet.
+Denotes
lead-free package.
*EP
= Exposed paddle.
**Dice
are designed to operate from 0°C to +70°C, but are tested
and guaranteed only at T
A
= +25°C.
Ordering Information continued at end of data sheet.
Typical Operating Circuits
C
AZ
V
CC
V
CC
V
CC
CAZ1
CAZ2
C
IN
0.01µF
IN+
100Ω
IN-
MAX3264CUE
MAX3265CUE
MAX3265EUE
OUT+
R
TERM
0.01µF
OUT-
0.01µF
R
L
100Ω
MAX3266
MAX3267
C
IN
0.01µF
TH
SQUELCH
LOS
LOS
LEVEL
V
CC
R
TH
N.C.
LOSS N.C.
OF
SIGNAL
N.C.
R
TERM
Typical Operating Circuits continued 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.
+3.0V to +5.5V, 1.25Gbps/2.5Gbps
Limiting Amplifiers
MAX3264/MAX3265/MAX3268/MAX3269/MAX3765/MAX3768
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V
CC
) ............................................-0.5V to +6.0V
Voltage at IN+, IN- ..........................(V
CC
- 2.4V) to (V
CC
+ 0.5V)
Voltage at SQUELCH, CAZ1,
CAZ2, LOS,
LOS,
TH..................................-0.5V to (V
CC
+ 0.5V)
Voltage at LEVEL...................................................-0.5V to +2.0V
Current into LOS,
LOS
..........................................-1mA to +9mA
Differential Input Voltage (IN+ - IN-) .....................................2.5V
Continuous Current at
CML Outputs (OUT+, OUT-) ..........................-25mA to +25mA
Continuous Current at PECL Outputs (OUT+, OUT-) .........50mA
Continuous Power Dissipation (T
A
= +70°C)
16-Pin TSSOP (derate 27mW/°C above +70°C) .........2162mW
10-Pin µMAX (derate 20mW/°C above +70°C) ...........1600mW
Operating Ambient Temperature Range .............-40°C to +85°C
Storage Temperature Range .............................-55°C to +150°C
Processing Temperature (dice) .......................................+400°C
Lead Temperature (soldering, 10s) .................................+300°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
(Data outputs terminated per Figure 1, V
CC
= +3.0V to +5.5V,
T
A
= 0°C to +70°C.
Typical values are at V
CC
= +3.3V, T
A
= +25°C,
unless otherwise noted.) (Note 1)
PARAMETER
Data Rate
Input Voltage Range
Deterministic Jitter
Random Jitter
CONDITIONS
MAX3264/MAX3268/MAX3768
MAX3265/MAX3269/MAX3765
MAX3264/MAX3268/MAX3768
MAX3265/MAX3269/MAX3765
MAX3264/MAX3268/MAX3768 (Notes 2, 3)
MAX3265/MAX3269/MAX3765 (Notes 2, 3)
MAX3264/MAX3268/MAX3768 (Notes 2, 4)
MAX3265/MAX3269/MAX3765 (Notes 2, 4)
MAX3264 (Note 5)
Data Output Edge Speed
MAX3265/MAX3765 (Note 6)
MAX3268/MAX3768 (Note 5)
MAX3269 (Note 6)
LOS Hysteresis
LOS Assert/Deassert Time
Low LOS Assert Level
Low LOS Deassert Level
(Notes 2, 7)
(Notes 7, 8)
R
TH
= 2.5kΩ
R
TH
= 2.5kΩ
MAX3264/MAX3268/MAX3768
MAX3265/MAX3269/MAX3765
MAX3264/MAX3268/MAX3768
MAX3265/MAX3269/MAX3765
1.20
2.20
2.5
80
80
5
10
14
11
15
8
175
100
150
100
4.4
1
2.6
4.8
4.5
8.5
300
150
300
150
dB
µs
mV
mV
ps
MIN
TYP
1.25
2.5
1200
1200
30
25
MAX
UNITS
Gbps
mV
psp-p
ps
RMS
2
_______________________________________________________________________________________
+3.0V to +5.5V, 1.25Gbps/2.5Gbps
Limiting Amplifiers
ELECTRICAL CHARACTERISTICS (continued)
(Data outputs terminated per Figure 1, V
CC
= +3.0V to +5.5V,
T
A
= 0°C to +70°C.
Typical values are at V
CC
= +3.3V, T
A
= +25°C,
unless otherwise noted.) (Note 1)
PARAMETER
Medium LOS Assert Level
Medium LOS Deassert Level
High LOS Assert Level
High LOS Deassert Level
Squelch Input Current
Differential Input Resistance
Input-Referred Noise
CML Output Voltage
PECL Output High Voltage
PECL Output Low Voltage
LOS Output High Voltage
LOS Output Low Voltage
Output Signal When Squelched
Power-Supply Rejection Ratio
Low-Frequency Cutoff
Output Resistance (Single Ended)
IN+ to IN-
MAX3264/MAX3268/MAX3768
MAX3265/MAX3269/MAX3765
LEVEL = open, R
LOAD
= 50Ω
LEVEL = GND, R
LOAD
= 75Ω
Referenced to V
CC
Referenced to V
CC
I
LOS
= -30µA
I
LOS
= +1.2mA
Outputs AC-coupled
f < 2MHz
C
AZ
= open
C
AZ
= 0.1µF
MAX3264/MAX3265/MAX3765
MAX3268/MAX3269/MAX3768
MAX3268
MAX3269
MAX3264
Power-Supply Current
Figure 2
Output not
squelched
Output squelched
MAX3265
MAX3765
MAX3768
MAX3765
85
20
20
2
2
100
4
39
48
38
50
50
39
64
62
78
62
76
76
62
90
mA
115
550
1100
-1.025
-1.810
2.4
0.4
1270
R
TH
= 7kΩ
R
TH
= 7kΩ
R
TH
= 20kΩ
R
TH
= 20kΩ
CONDITIONS
MAX3264/MAX3268/MAX3768
MAX3265/MAX3269/MAX3765
MAX3264/MAX3268/MAX3768
MAX3265/MAX3269/MAX3765
MAX3264/MAX3268/MAX3768
MAX3265/MAX3269/MAX3765
MAX3264/MAX3268/MAX3768
MAX3265/MAX3269/MAX3765
0
97
9.4
18.0
MIN
5.6
9.9
TYP
9
16
15
27
21.6
41.5
35
67
80
100
150
230
1200
1800
-0.880
-1.620
400
103
19.8
40.5
MAX
UNITS
mV
mV
mV
mV
µA
Ω
µV
RMS
mV
V
V
V
V
mV
dB
MHz
kHz
Ω
MAX3264/MAX3265/MAX3268/MAX3269/MAX3765/MAX3768
_______________________________________________________________________________________
3
+3.0V to +5.5V, 1.25Gbps/2.5Gbps
Limiting Amplifiers
MAX3264/MAX3265/MAX3268/MAX3269/MAX3765/MAX3768
ELECTRICAL CHARACTERISTICS—MAX3265EUE
(Data outputs terminated per Figure 1, V
CC
= +3.0V to +5.5V,
T
A
= -40°C to +85°C.
Typical values are at V
CC
= +3.3V, T
A
= +25°C,
unless otherwise noted.) (Note 1)
PARAMETER
Data Rate
Input Voltage Range
Deterministic Jitter
Random Jitter
Data Output Edge Speed
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
Squelch Input Current
Differential Input Resistance
Input-Referred Noise
CML Output Voltage
LOS Output High Voltage
LOS Output Low Voltage
Output Signal When Squelched
Power-Supply Rejection Ratio
Low-Frequency Cutoff
Output Resistance (single ended)
Power-Supply Current
Figure 2
LEVEL = open, R
LOAD
= 50Ω
LEVEL = GND, R
LOAD
= 75Ω
I
LOS
= -30µA
I
LOS
= +1.2mA
Outputs AC-coupled
f < 2MHz
C
AZ
= open
C
AZ
= 0.1µF
85
20
20
2
2
100
50
115
76
550
1100
2.4
0.450
1270
IN+ to IN-
(Notes 2, 3)
(Notes 2, 4)
(Note 6)
(Notes 2, 7)
(Notes 7, 8)
R
TH
= 2.5kΩ
R
TH
= 2.5kΩ
R
TH
= 7kΩ
R
TH
= 7kΩ
R
TH
= 20kΩ
R
TH
= 20kΩ
0
97
18.0
9.9
2.20
2.2
10
11
8
100
4.4
1
4.8
8.5
16
27
41.5
67
80
100
230
1200
1800
111
400
103
43.0
13.6
155
CONDITIONS
MIN
TYP
2.5
1200
25
MAX
UNITS
Gbps
mV
ps
p-p
ps
RMS
ps
dB
µs
mV
mV
mV
mV
mV
mV
µA
Ω
µV
RMS
mV
V
V
mV
dB
MHz
kHz
Ω
mA
Note 1:
Specifications for Input Voltage Range, LOS Assert/Deassert Levels, and CML Output Voltage refer to the total differential
peak-to-peak signal applied or measured. PECL output voltages are absolute (single-ended) voltages measured at a single
output.
Note 2:
Input edge speed is controlled using four-pole, lowpass Bessel filters with bandwidth approximately 75% of the maximum
data rate.
Note 3:
Deterministic jitter is measured with a K28.5 pattern (0011 1110 1011 0000 0101). Deterministic jitter is the peak-to-peak
deviation from ideal time crossings, measured at the zero-level crossings of the differential output per ANSI X3.230,
Annex A.
Note 4:
Random jitter is measured with the minimum input signal applied after filtering with a four-pole, lowpass, Bessel filter (fre-
quency bandwidth at 75% of the maximum data rate). For Fibre Channel and Gigabit Ethernet applications, the peak-to-
peak random jitter is 14.1-times the RMS random jitter.
Note 5:
Input signal applied after a 933MHz Bessel filter.
Note 6:
Input signal applied after a 1.8GHz Bessel filter.
Note 7:
Input for LOS assert/deassert and hysteresis tests is a repeating K28.5 pattern. Hysteresis is defined as:
20log (V
LOS-DEASSERT
/ V
LOS-ASSERT
).
Note 8:
Response time to a 10dB change in input power.
4
_______________________________________________________________________________________
+3.0V to +5.5V, 1.25Gbps/2.5Gbps
Limiting Amplifiers
Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
OUTPUT VOLTAGE
vs. INPUT VOLTAGE
MAX3264/5/8/9 TOC01a
MAX3264/MAX3265/MAX3268/MAX3269/MAX3765/MAX3768
MAX3264
LOS HYSTERESIS vs. TEMPERATURE
MAX3264/5/8/9 TOC03a
MAX3265EUE
LOS HYSTERESIS vs. TEMPERATURE
MAX3264/5/8/9 TOC03
1700
1500
OUTPUT VOLTAGE (mV)
MAX3264/MAX3268
1300
1100
900
700
500
300
0
2
4
6
8
10
MAX3265/MAX3269/MAX3765
6.5
6.0
LOS HYSTERESIS (dB)
5.5
5.0
R
TH
= 7kΩ
4.5
4.0
3.5
R
TH
= 25kΩ
6.5
6.0
LOS HYSTERESIS (dB)
5.5
5.0
4.5
4.0
3.5
R
TH
= 16kΩ
R
TH
= 4.6kΩ
12
0
10
20
30
40
50
60
70
-40
-15
10
35
60
85
INPUT VOLTAGE (mV)
TEMPERATURE (°C)
TEMPERATURE (°C)
MAX3264/MAX3268/MAX3768
DETERMINISTIC JITTER
vs. INPUT AMPLITUDE
MAX3264/5/8/9 TOC04
MAX3264/MAX3268/MAX3768
RANDOM JITTER
vs. INPUT AMPLITUDE
14
12
RMS JITTER (ps)
10
8
6
4
MAX3264/5/8/9 TOC05
MAX3265/MAX3269/MAX3765
DETERMINISTIC JITTER
vs. INPUT AMPLITUDE
MAX3264/5/8/9 TOC06
30
25
20
JITTER (ps)
15
10
5
0
0
200
400
600
800
1000
16
30
25
20
JITTER (ps)
15
10
5
0
2
0
1200
0
10
20
30
40
50
INPUT AMPLITUDE (mV)
INPUT AMPLITUDE (mV)
0
200
400
600
800
1000
1200
INPUT AMPLITUDE (mV)
MAX3265/MAX3269/MAX3765
RANDOM JITTER
vs. INPUT AMPLITUDE
MAX3264/5/8/9 TOC07
LOSS OF SIGNAL WITH SQUELCH
V
IN
MAX3264/5/8/9 TOC08
MAX3268/MAX3768
DATA OUTPUT EYE DIAGRAM
(MINIMUM INPUT)
MAX3264/5/8/9 TOC09
8
7
6
RMS JITTER (ps)
5
4
3
2
1
0
0
10
20
30
40
V
OUT
300mV/div
V
LOS
50
500ns/div
200ps/div
INPUT AMPLITUDE (mV)
_______________________________________________________________________________________
5
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