V
CC
V
CC
C
AZ
CAZ1
CAZ2
V
CC
V
CC
C
IN
0.01
µF
0.01
µF
0.01
µF
C
IN
0.01
µF
TH
SQUELCH
N.C.
100
IN-
IN+
OUT+
R
TERM
R
TERM
R
L
100
OUT-
MAX3266
MAX3267
MAX3264CUE
MAX3265CUE
MAX3265EUE
LOS
LOSS
OF
SIGNAL
LOS
N.C.
R
TH
LEVEL
N.C.
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.
Applications
Gigabit Ethernet Optical Receivers
Fibre Channel Optical Receivers
System Interconnect
ATM Optical 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
MAX3264/MAX3265/MAX3268/MAX3269/MAX3765/MAX3768
+3.0V to +5.5V, 1.25Gbps/2.5Gbps
Limiting Amplifiers
________________________________________________________________ Maxim Integrated Products
1
19-1523; Rev 6, 5/04
+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
Selector Guide appears at end of data sheet.
Pin Configurations appear at end of data sheet.
Typical Operating Circuits
Typical Operating Circuits continued at end of data sheet.
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.
PART
TEMP RANGE
PIN-PACKAGE
MAX3264
CUE
0
°C to +70°C
16 TSSOP-EP*
MAX3264CUE+
0
°C to +70°C
16 TSSOP-EP*
MAX3264C/D
0
°C to +70°C
Dice**
MAX3265
CUE
0
°C to +70°C
16 TSSOP-EP*
MAX3265CUE+
0
°C to +70°C
16 TSSOP-EP*
MAX3265CUB
0
°C to +70°C
10 µMAX-EP*
MAX3265CUB+
0
°C to +70°C
10 µMAX-EP*
MAX3265EUE
-40
°C to +85°C
16 TSSOP-EP*
MAX3265EUE+
-40
°C to +85°C
16 TSSOP-EP*
MAX3265C/D
0
°C to +70°C
Dice**
Ordering Information continued at end of data sheet.
MAX3264/MAX3265/MAX3268/MAX3269/MAX3765/MAX3768
+3.0V to +5.5V, 1.25Gbps/2.5Gbps
Limiting Amplifiers
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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)
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.
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
Deterministic Jitter
MAX3265/MAX3269/MAX3765 (Notes 2, 3)
MAX3265/MAX3269/MAX3765
MAX3264/MAX3268/MAX3768
MAX3265/MAX3269/MAX3765
MAX3264/MAX3268/MAX3768
4.5
8.5
Low LOS Deassert Level
mV
R
TH
= 2.5k
MAX3264/MAX3268/MAX3768 (Notes 2, 3)
PARAMETER
MIN
TYP
MAX
UNITS
10
1200
5
1200
Data Rate
Gbps
Input Voltage Range
mV
14
30
11
25
1.25
2.5
psp-p
15
Random Jitter
8
ps
RMS
80
175
300
100
150
80
150
300
Data Output Edge Speed
100
150
ps
LOS Hysteresis
2.5
4.4
dB
LOS Assert/Deassert Time
1
µs
1.20
2.6
2.20
4.8
Low LOS Assert Level
mV
CONDITIONS
MAX3264/MAX3268/MAX3768 (Notes 2, 4)
MAX3265/MAX3269/MAX3765
MAX3264/MAX3268/MAX3768
MAX3265/MAX3269/MAX3765 (Notes 2, 4)
MAX3264 (Note 5)
MAX3265/MAX3765 (Note 6)
MAX3268/MAX3768 (Note 5)
MAX3269 (Note 6)
MAX3264/MAX3268/MAX3768
(Notes 2, 7)
MAX3265/MAX3269/MAX3765
(Notes 7, 8)
R
TH
= 2.5k
MAX3264/MAX3265/MAX3268/MAX3269/MAX3765/MAX3768
+3.0V to +5.5V, 1.25Gbps/2.5Gbps
Limiting Amplifiers
_______________________________________________________________________________________
3
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
CONDITIONS
MIN
TYP
MAX
UNITS
MAX3264/MAX3268/MAX3768
5.6
9
Medium LOS Assert Level
R
TH
= 7k
MAX3265/MAX3269/MAX3765
9.9
16
mV
MAX3264/MAX3268/MAX3768
15
19.8
Medium LOS Deassert Level
R
TH
= 7k
MAX3265/MAX3269/MAX3765
27
40.5
mV
MAX3264/MAX3268/MAX3768
9.4
21.6
High LOS Assert Level
R
TH
= 20k
MAX3265/MAX3269/MAX3765
18.0
41.5
mV
MAX3264/MAX3268/MAX3768
35
High LOS Deassert Level
R
TH
= 20k
MAX3265/MAX3269/MAX3765
67
mV
Squelch Input Current
0
80
400
µA
Differential Input Resistance
IN+ to IN-
97
100
103
MAX3264/MAX3268/MAX3768
150
Input-Referred Noise
MAX3265/MAX3269/MAX3765
230
µV
RMS
LEVEL = open, R
LOAD
= 50
550
1200
CML Output Voltage
LEVEL = GND, R
LOAD
= 75
1100
1270
1800
mV
PECL Output High Voltage
Referenced to V
CC
-1.025
-0.880
V
PECL Output Low Voltage
Referenced to V
CC
-1.810
+1.620
V
LOS Output High Voltage
I
LOS
= -30µA
2.4
V
LOS Output Low Voltage
I
LOS
= +1.2mA
0.4
V
Output Signal When Squelched
Outputs AC-coupled
20
mV
Power-Supply Rejection Ratio
f < 2MHz
20
dB
C
AZ
= open
2
MHz
Low-Frequency Cutoff
C
AZ
= 0.1µF
2
kHz
MAX3264/MAX3265/MAX3765
85
100
115
O utp ut Resi stance ( S i ng l e E nd ed )
MAX3268/MAX3269/MAX3768
4
MAX3268
39
62
MAX3269
48
78
MAX3264
38
62
MAX3265
50
76
MAX3765
50
76
Output not
squelched
MAX3768
39
62
Power-Supply Current
Figure 2
Output squelched
MAX3765
64
90
mA
mV
V
V
mV
MAX3264/MAX3265/MAX3268/MAX3269/MAX3765/MAX3768
+3.0V to +5.5V, 1.25Gbps/2.5Gbps
Limiting Amplifiers
4
_______________________________________________________________________________________
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.
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)
CONDITIONS
Data Rate
Gbps
2.5
UNITS
MIN
TYP
MAX
PARAMETER
Input Voltage Range
mV
10
1200
(Notes 2, 3)
Deterministic Jitter
ps
p-p
11
25
(Notes 2, 4)
Random Jitter
ps
RMS
8
(Note 6)
Data Output Edge Speed
ps
100
155
(Notes 2, 7)
LOS Hysteresis
dB
2.2
4.4
(Notes 7, 8)
LOS Assert/Deassert Time
µs
1
Output Resistance (single ended)
85
100
115
C
AZ
= 0.1µF
kHz
2
C
AZ
= open
Low-Frequency Cutoff
MHz
2
f < 2MHz
Power-Supply Rejection Ratio
dB
20
Outputs AC-coupled
Output Signal When Squelched
20
I
LOS
= +1.2mA
LOS Output Low Voltage
0.450
I
LOS
= -30µA
LOS Output High Voltage
LEVEL = GND, R
LOAD
= 75
1100
1270
1800
LEVEL = open, R
LOAD
= 50
CML Output Voltage
550
1200
Input-Referred Noise
µV
RMS
230
IN+ to IN-
Differential Input Resistance
97
100
103
Squelch Input Current
µA
0
80
400
R
TH
= 20k
High LOS Deassert Level
mV
67
111
R
TH
= 20k
High LOS Assert Level
mV
18.0
41.5
R
TH
= 7k
Medium LOS Deassert Level
mV
27
43.0
R
TH
= 7k
Medium LOS Assert Level
mV
9.9
16
R
TH
= 2.5k
Low LOS Deassert Level
mV
8.5
13.6
R
TH
= 2.5k
Low LOS Assert Level
mV
2.20
4.8
Figure 2
Power-Supply Current
mA
50
76
2.4
MAX3264/MAX3265/MAX3268/MAX3269/MAX3765/MAX3768
+3.0V to +5.5V, 1.25Gbps/2.5Gbps
Limiting Amplifiers
_______________________________________________________________________________________
5
0
25
20
15
10
5
30
0
200
400
600
800
1000
1200
MAX3264/MAX3268/MAX3768
DETERMINISTIC JITTER
vs. INPUT AMPLITUDE
MAX3264/5/8/9 TOC04
INPUT AMPLITUDE (mV)
JITTER (ps)
0
14
12
10
8
6
2
4
16
0
10
20
30
40
50
MAX3264/MAX3268/MAX3768
RANDOM JITTER
vs. INPUT AMPLITUDE
MAX3264/5/8/9 TOC05
INPUT AMPLITUDE (mV)
RMS JITTER (ps)
300
900
700
500
1300
1100
1500
1700
0
2
4
6
8
10
12
OUTPUT VOLTAGE
vs. INPUT VOLTAGE
MAX3264/5/8/9 TOC01a
INPUT VOLTAGE (mV)
OUTPUT VOLTAGE (mV)
MAX3264/MAX3268
MAX3265/MAX3269/MAX3765
3.5
4.0
6.5
6.0
5.5
5.0
4.5
0
10
20
30
40
50
60
70
MAX3264
LOS HYSTERESIS vs. TEMPERATURE
MAX3264/5/8/9 TOC03a
TEMPERATURE (°C)
LOS HYSTERESIS (dB)
R
TH
= 25k
R
TH
= 7k
0
25
20
15
10
5
30
0
200
400
600
800
1000
1200
MAX3265/MAX3269/MAX3765
DETERMINISTIC JITTER
vs. INPUT AMPLITUDE
MAX3264/5/8/9 TOC06
INPUT AMPLITUDE (mV)
JITTER (ps)
0
7
6
5
4
3
1
2
8
0
10
20
30
40
50
MAX3265/MAX3269/MAX3765
RANDOM JITTER
vs. INPUT AMPLITUDE
MAX3264/5/8/9 TOC07
INPUT AMPLITUDE (mV)
RMS JITTER (ps)
V
IN
V
OUT
V
LOS
LOSS OF SIGNAL WITH SQUELCH
MAX3264/5/8/9 TOC08
500ns/div
300mV/div
200ps/div
MAX3268/MAX3768
DATA OUTPUT EYE DIAGRAM
(MINIMUM INPUT)
MAX3264/5/8/9 TOC09
Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
3.5
4.0
6.5
6.0
5.5
5.0
4.5
-40
-15
10
35
60
85
MAX3265EUE
LOS HYSTERESIS vs. TEMPERATURE
MAX3264/5/8/9 TOC03
TEMPERATURE (
°C)
LOS HYSTERESIS (dB)
R
TH
= 4.6k
R
TH
= 16k
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