19-1953; Rev 3; 12/05
3.2Gbps Adaptive Equalizer
and Cable Driver
General Description
The MAX3800 is a +3.3V adaptive cable equalizer and
cable driver implemented together on a single chip. It is
designed for coaxial and twin-axial cable point-to-point
communications applications. The driver features differ-
ential current-mode logic (CML) inputs and outputs as
well as adjustable output amplitude. The equalizer
includes differential CML data inputs and outputs, a
loss-of-signal (LOS) output, and a cable integrity moni-
tor (CIM) output.
The adaptive cable equalizer is capable of equalizing
differential or single-ended signals at data rates up to
3.2Gbps. It automatically adjusts to attenuation caused
by skin-effect losses of up to 30dB at 1.6GHz. The
equalizer effectively extends the usable length of cop-
per cable in high-frequency interconnect applications.
The MAX3800 is available in a 32-pin TQFP package
with exposed pad and consumes only 200mW at
+3.3V. The driver can be disconnected from the power
supply when it is not needed, resulting in a 40% reduc-
tion in supply current.
♦
Single +3.3V Operation
♦
Typical Power Dissipation = 200mW at +3.3V
♦
Data Rates Up to 3.2Gbps
♦
Adjustable Cable Driver Output Amplitude
♦
Equalizer Automatically Adjusts for Different
Cable Lengths
♦
0dB to 30dB Equalization at 1.6GHz (3.2Gbps)
♦
Loss-of-Signal (LOS) Indicator
♦
Cable Integrity Monitor (CIM)
♦
On-Chip Input and Output Terminations
♦
Low External Component Count
♦
Operating Temperature Range = 0°C to +85°C
♦
ESD Protection on Cable Inputs and Outputs
Features
MAX3800
Applications
High-Speed Links in Communications
and Data Systems
Backplane and Interconnect Applications
SDH/SONET Transmission Equipment
Pin Configuration appears at end of data sheet.
PART
MAX3800UGJ
MAX3800UHJ
MAX3800UHJ+
Ordering Information
TEMP
RANGE
0°C to +85°C
0°C to +85°C
0°C to +85°C
PIN-
PACKAGE
32 QFN
32 TQFP-EP*
32 TQFP-EP*
PKG
CODE
G3255-1
AA-EP
AA-EP
*EP
= exposed pad
+Denotes
lead-free package.
Typical Application Circuit
+3.3V
+3.3V
DIN
CARD 1
MAX3800
EOUT
LOS
RMOD
DOUT
EIN
MAX3800
EOUT
CARD 2
DIN
RMOD
CIM
EIN
CIM
DOUT
LOS
THIS SYMBOL INDICATES A CONTROLLED-IMPEDANCE TRANSMISSION LINE.
________________________________________________________________
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.
3.2Gbps Adaptive Equalizer
and Cable Driver
MAX3800
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V
CC
..............................................-0.5V to +6.0V
Voltage at
LOS,
RMOD, and CIM...............-0.5V to (V
CC
+ 0.5V)
Voltage at EIN+, EIN-, DIN+, DIN- .....(V
CC
- 1V) to (V
CC
+ 0.5V)
Current Out of EOUT+, EOUT-, DOUT+, DOUT- ................25mA
Continuous Power Dissipation (T
A
= +85°C)
32-Pin TQFP-EP (derate 22.2mW/°C above +85°C) ...1444mW
Operating Ambient Temperature Range ................0°C to +85°C
Storage Temperature Range .............................-55°C to +150°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.
DC ELECTRICAL CHARACTERISTICS
(V
CC
= +3.14V to +3.46V, T
A
= 0°C to +85°C. Typical values are at V
CC
= +3.3V and T
A
= +25°C, unless otherwise noted.)
PARAMETER
Supply Current
SYMBOL
I
CC
V
DIN+,
V
DIN-
V
DIN
V
DIN
= (V
DIN+
) - (V
DIN-
)
Single-ended
R
MOD
= 10kΩ (Note 2)
R
MOD
= 20kΩ (Note 2)
Single-ended
3.2Gbps, 30dB cable loss at 1.6GHz (Note 3)
Single-ended
(Note 2)
Single-ended
V
CIM
V
CIM+,
V
CIM-
No external load, V
CIM
= (V
CIM+
) - (V
CIM-
)
No external load
Output high (Note 4)
Output low (Note 4)
Each output DC-coupled 50Ω to V
CC
V
CC
- 0.2
45
500
50
-0.5
0.5
2.4
0.4
62.5
CONDITIONS
Includes external load current (Note 1)
V
CC
- 0.6
400
45
750
400
50
55
870
450
62.5
650
1100
55
65
1000
75
+0.5
V
CC
- 0.5
MIN
TYP
65
MAX
85
V
CC
+ 0.2
1100
65
1000
550
75
700
UNITS
mA
CABLE DRIVER INPUT SPECIFICATIONS
Input Voltage (Single-Ended)
Input Voltage (Differential)
Input Impedance
CABLE DRIVER OUTPUT SPECIFICATIONS
Output Voltage
(Differential)
Output Impedance
CABLE EQUALIZER INPUT SPECIFICATIONS
Minimum Cable Input (Differential)
Maximum Cable Input (Differential)
Input Impedance
Output Voltage (Differential)
Output Impedance
Voltage at CIM Output (Differential)
Voltage at CIM Output
(Single-Ended)
Voltage at
LOS
Output Common-Mode Voltage
CABLE EQUALIZER OUTPUT SPECIFICATIONS
mVp-p
Ω
Vp-p
V
V
V
V
mVp-p
mVp-p
Ω
mVp-p
mVp-p
Ω
V
mVp-p
Ω
2
_______________________________________________________________________________________
3.2Gbps Adaptive Equalizer
and Cable Driver
AC ELECTRICAL CHARACTERISTICS
(V
CC
= +3.14V to +3.46V, T
A
= 0°C to +85°C. Typical values are at V
CC
= +3.3V and T
A
= +25°C, unless otherwise noted.) (Note 5)
PARAMETER
Maximum Input Data Rate
CABLE DRIVER SPECIFICATIONS
Random Jitter
Deterministic Jitter
Output Edge Speed
Input Return Loss (Single-Ended)
Output Return Loss (Single-Ended)
EQUALIZER SPECIFICATIONS
0dB cable loss (Note 8)
Residual Jitter (Note 7)
Output Edge Speed
Input Return Loss (Single-Ended)
Output Return Loss (Single-Ended)
Equalization Compensation
Equalization Time Constant
24dB cable loss (Note 8)
30dB cable loss (Note 8)
20% to 80%
≤3.2GHz
≤3.2GHz
1.6GHz (skin-effect losses only)
30
5
170
97
112
56
14
14
240
200
200
77
mUIp-p
mUIp-p
mUIp-p
ps
dB
dB
dB
µs
(Note 6)
(Note 6)
20% to 80%
≤3.2GHz
≤3.2GHz
2
20
59
14
14
4
60
76
mUI
RMS
mUIp-p
ps
dB
dB
SYMBOL
CONDITIONS
MIN
3.2
TYP
MAX
UNITS
Gbps
MAX3800
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
Equalizer and driver total currents (equalizer with maximum equalization and driver with maximum output swing).
Input voltage within specification limits, 50Ω to V
CC
at each output.
Minimum cable input for
LOS
to assert high.
100kΩ load to ground.
AC electrical characteristics are guaranteed by design and characterization.
V
DIN
= 400mVp-p to 1100mVp-p (differential), 10kΩ
≤
RMOD
≤
20kΩ, 3.2Gbps 2
13
-1 PRBS with 100 consecutive ones and
100 consecutive zeros substituted.
Note 7:
Includes random jitter and deterministic jitter.
Note 8:
Differential cable input voltage = 700mVp-p, 3.2Gbps 2
13
-1 PRBS with 100 consecutive ones and 100 consecutive zeros
substituted. Cable loss is due to skin effect only.
_______________________________________________________________________________________
3
3.2Gbps Adaptive Equalizer
and Cable Driver
MAX3800
Typical Operating Characteristics
(T
A
= +25°C, V
CC
= +3.3V, all jitter measurements done at 3.2Gbps, 700mV cable input with 2
13
-1 PRBS pattern with 100 consecutive
ones and 100 consecutive zeros substituted.
Note:
Test pattern produces near worst-case jitter results. Results will vary with pattern,
unless otherwise noted.)
DRIVER INPUT RETURN LOSS (S11)
SUPPLY CURRENT vs. TEMPERATURE
CABLE DRIVER OUTPUT VOLTAGE vs. RMOD
MAX3800 toc01
65
60
SUPPLY CURRENT (mA)
55
50
45
40
35
30
25
20
0
DRIVER + EQUALIZER
MAX3800 toc02
1200
DRIVER OUTPUT VOLTAGE (mV)
1100
1000
900
800
700
600
500
400
40
30
20
GAIN (dB)
10
0
-10
-20
-30
-40
-50
EQUALIZER
DRIVER
10
20
30
40
50
60
70
80
90
4
7
10
13
R
MOD
(kΩ)
16
19
22
0
0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0
FREQUENCY (GHz)
TEMPERATURE (°C)
DRIVER OUTPUT RETURN LOSS (S22)
MAX3800 toc04
40
30
20
GAIN (dB)
10
0
-10
-20
-30
-40
-50
0
MAX3800 toc05
130
120
25 FT
50
JITTER (ps
p-p
)
45
JITTER (ps
p-p
)
110
100
72 FT
90
40
35
80
30
0.001
70
0.01
0.1
1
10
100
NOISE FREQUENCY (MHz)
300 400 500 600 700 800 900 1000 1100
CABLE INPUT AMPLITUDE (mV)
0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0
FREQUENCY (GHz)
MAX3800 toc07
90
80
JITTER (ps
p-p
)
70
60
2.5Gbps
50
40
30
20
10
3.05
20
6.1
30
40
9.14
12.19
CABLE LENGTH
3.2Gbps
622Mbps
MAX3800 toc08
140
120
100
80
60
2.5Gbps
100
90
JITTER (ps
p-p
)
3.2Gbps
JITTER (ps
p-p
)
80
70
60
50
2.5Gbps
3.2Gbps
622Mbps
622Mbps
50 (FEET)
15.24 (METERS)
40
25
35
45
55
65
75
85
95 (FEET)
7.65 10.67 13.72 16.76 19.81 22.86 25.91 28.96 (METERS)
CABLE LENGTH
40
40 45 50 55 60 65 70 75 80 85 (INCHES)
1.02 1.14 1.27 1.40 1.52 1.65 1.77 1.90 2.03 2.16 (METERS)
LINE LENGTH
4
_______________________________________________________________________________________
MAX3800 toc09
100
EQUALIZER RESIDUAL JITTER vs.
CABLE LENGTH (MADISON #13887 SHIELDED
TWISTED PAIR-DIFFERENTIAL)
160
EQUALIZER RESIDUAL JITTER vs.
CABLE LENGTH (RG179B 75Ω COAXIAL
CABLE - SINGLE-ENDED)
EQUALIZER RESIDUAL JITTER vs. LINE LENGTH
(FR-4 6MIL STRIPLINE - SINGLE-ENDED)
110
MAX3800 toc06
50
EQUALIZER RESIDUAL JITTER vs. POWER SUPPLY
NOISE (100mVp-p SINE WAVE) (40FT OF MADISON
#14887 SHIELDED TWISTED PAIR-DIFFERENTIAL)
55
140
EQUALIZER RESIDUAL JITTER vs. CABLE
INPUT AMPLITUDE (RG179B 75Ω
COAXIAL CABLE - SINGLE-ENDED)
MAX3800 toc03
70
1300
50
3.2Gbps Adaptive Equalizer
and Cable Driver
MAX3800
Typical Operating Characteristics (continued)
(T
A
= +25°C, V
CC
= +3.3V, all jitter measurements done at 3.2Gbps, 700mV cable input with 2
13
-1 PRBS pattern with 100 consecutive
ones and 100 consecutive zeros substituted.
Note:
Test pattern produces near worst-case jitter results. Results will vary with pattern,
unless otherwise noted.)
EQUALIZER OUTPUT EYE DIAGRAM
EQUALIZER OUTPUT EYE DIAGRAM
EQUALIZER INPUT AFTER
AFTER 100FT OF 75Ω RG179 CABLE
AFTER 115FT OF 50Ω GORE 89 CABLE
115FT OF CABLE (TOP)
(SINGLE-ENDED, 2
7
-1 PRBS)
(DIFFERENTIAL, 2
7
-1 PRBS)
EQUALIZER OUTPUT (BOTTOM)
MAX3800 toc10
MAX3800 toc11
MAX3800 toc12
60ps/div (2.5Gbps)
68ps/div (2.5Gbps)
EQUALIZER OUTPUT EYE DIAGRAM
AFTER 100FT OF BELDEN 9207 CABLE
(DIFFERENTIAL, 2
7
-1 PRBS)
MAX3800 toc13
EQUALIZER OUTPUT EYE DIAGRAM
AFTER 50FT OF MADISON #14887
SHIELDED TWISTED PAIR CABLE
(DIFFERENTIAL, 2
7
-1 PRBS)
MAX3800 toc14
CIM VOLTAGE vs. CABLE LENGTH
(RG179B 75Ω COAXIAL CABLE -
SINGLE-ENDED)
MAX3800 toc15
1.8
1.7
CIM VOLTAGE (V)
1.6
1.5
1.4
1.3
1.2
CIM+
CIM-
60ps/div (2.5Gbps)
60ps/div (2.5Gbps)
0
10 20 30 40 50 60 70 80 90 100
CABLE LENGTH (FEET)
EQUALIZER INPUT RETURN LOSS (S11)
MAX3800 toc16
EQUALIZER OUTPUT RETURN LOSS (S22)
40
30
20
GAIN (dB)
10
0
-10
-20
-30
-40
-50
MAX3800 toc17
50
40
30
20
GAIN (dB)
10
0
-10
-20
-30
-40
-50
0
50
0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0
FREQUENCY (GHz)
0
0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0
FREQUENCY (GHz)
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5
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