Datasheet
See the Typical Operating Characteristics Cable Driver
Output Voltage vs. R
MOD
for typical values.
Cable Integrity Monitor
The CIM_ output voltage is directly proportional to the
output current of the loop amplifier (which controls the
current-steering network; see Detailed Description). This
is an analog voltage output that indicates the amount of
equalization being applied.
The amount of equalization (and thus the CIM_ output
level) is affected by cable type, cable length, signal band-
width, etc. See the Typical Operating Characteristics CIM
Voltage vs. Cable Length for typical values under specific
conditions.
Loss-of-Signal (LOS_) Output
Loss of signal is indicated by the LOS_ output. A low level
on LOS_ indicates that the equalizer input power has
dropped below a threshold. When there is sufficient input
voltage to the channel (typically greater than 250mV),
LOS_ is high. The LOS_ output is suitable for indicat-
ing problems with the transmission link caused by, for
example, a broken cable or a defective driver.
Data Spectrum for Equalizer
The MAX3802 equalizer design requires the data stream
be scrambled or coded to provide a rich frequency spec-
trum for the adaptation algorithm. Scrambled patterns or
coded patterns with scrambled content, such as 64b/66b
or SONET PRBS, are ideal. Some coded patterns, such
as 8b/10b, lack low-frequency energy and can be nonop-
timal, requiring the user to characterize the specific appli-
cation. In the absence of an input signal (nonstandard
application), amplified noise may appear at the output due
to the large gain of the device.
Single-Ended Operation
For single-ended operation of the cable driver or equal-
izer, connect the unused input to ground through a
series combination of a capacitor (of equal value to other
AC-coupling capacitors) and a 50Ω resistor. Note that the
MAX3802 is specified for differential operation.
Layout Considerations
The MAX3802’s performance can be significantly affected
by circuit board layout and design. Use good high-fre-
quency design techniques, including minimizing ground
inductance and using controlled-impedance transmission
lines for the high-frequency data signals. Power-supply
decoupling capacitors should be placed as close as pos-
sible to V
CC
.
Exposed-Pad Package
The EP on the 68-pin TQFN provides a very low thermal
resistance path for heat removal from the IC. The pad is the
electrical ground on the MAX3802 and must be soldered
to the circuit board ground for proper thermal and electrical
performance. Refer to Maxim Application Note HFAN-08.1,
Thermal Considerations for QFN and Other Exposed-Pad
Packages (available at www.maximintegrated. com) for
additional application information.
V
CCD
1
RMOD1
V
CCE
1
EOUT1+
EOUT1-
V
CCE
1
DIN1+
DIN1-
V
CCD
1
DOUT1+
DOUT1-
CIM1
V
CCE
1
EIN1+
EIN1-
V
CCE
1
11
10
9
8
7
6
5
4
3
2
16
15
14
13
12
1
17LOS1
EIN2-
TQFN*
V
CCE
2
V
CCE
2
EIN2+
V
CCE
2
CIM2
EOUT2+
EOUT2-
RMOD2
V
CCE
2
DOUT2-
V
CCD
2
V
CCD
2
DOUT2+
DIN2-
2322212019 2726252418 2928 323130
DIN2+
3433
*THE EXPOSED PAD OF THE TQFN PACKAGE MUST BE SOLDERED TO GROUND
FOR PROPER THERMAL AND ELECTRICAL OPERATION OF THE MAX3802.
LOS2
38
39
40
41
42
43
44
45
46
47
DOUT3+
DOUT3-
V
CCD
3
RMOD3
V
CCE
3
EOUT3+
EOUT3-
V
CCE
3
CIM3
V
CCE
3
35
36
37
EIN3+
EIN3-
V
CCE
3
48 V
CCD
3
49
50
DIN3+
DIN3-
51 LOS3
5859606162 5455565763
DOUT4-
TOP VIEW
V
CCD
4
RMOD4
V
CCE
4
EOUT4+
EOUT4-
V
CCE
4
CIM4
V
CCE
4
EIN4+
5253
EIN4-
V
CCE
4
64
DOUT4+
656667
DIN4+
DIN4-
V
CCD
4
68
LOS4
MAX3802
+
MAX3802 3.2Gbps Quad Adaptive Cable Equalizer
with Cable Driver
www.maximintegrated.com
Maxim Integrated
│
10
Pin Conguration
Chip Information
PROCESS: BIPOLAR (silicon germanium)