MAX3812USA+ Maxim Integrated Products, MAX3812USA+ Datasheet - Page 6

• Manufacturer Part Number: MAX3812USA+
• Description: IC DRIVER CABLE SD/HD 8-SOIC
• Manufacturer: Maxim Integrated Products
• Type: Driverr

Specifications of MAX3812USA+

• Number Of Drivers/receivers: 1/0
• Protocol: LVDS
• Voltage - Supply: 3 V ~ 3.6 V
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX3812 output has a selectable slew-rate in
order to achieve compliance to SMPTE 259M/344M
and SMPTE 292M. Output slew rate is selected with the
SD/HD input (Figure 4). The SD/HD pin must be set
high for SMPTE 259M/344M standards and low for
SMPTE 292M standards.
The MAX3812 differential data outputs are current-mode
logic, CML (Figure 5). Each side of the differential output
will drive 800mV
mission line (R
The cable driver output must have a source impedance
of 75Ω and a return loss of at least 15dB between 5MHz
and 1.485GHz to comply with the SMPTE 259M, SMPTE
344M, and SMPTE 292M standards. In order to meet the
return loss specification, the output network shown in
the Typical Application Circuit is recommended.
Multirate SMPTE SD/HD Cable Driver
with Selectable Slew Rate
Figure 4. Slew-Rate Selection Switch
6
_______________________________________________________________________________________
SD/HD
SET
MAX3812
40kΩ
P-P
= 750Ω).
V
Slew-Rate Selection Switch
CC
into a doubly terminated 75Ω trans-
STRUCTURES
Differential Data Outputs
5kΩ
ESD
V
CC
V
CC
The value of the output inductor is typically 6.8nH, but the
value will vary depending on PC board layout. If the out-
puts are AC-coupled, a minimum capacitor value of 4.7µF
should be used to accommodate SMPTE pathological
test signals.
When measuring output return loss, it is necessary to take
the measurement for both a logic-high and logic-low
state. This is due to the output capacitance being slightly
dependent on the logic state. See the Output Return Loss
graph in the Typical Operating Characterisitics.
The external R
the RSET pin controls the output voltage swing (Figure 5).
Typically the output voltage swing is set to 800mV
using a value of 750Ω. For output voltage swings other
than 800mV
R
Using R
The R
to the RSET pin and the capacitance at this node should
be minimized.
Use controlled-impedance transmission lines to interface
with the MAX3812 high-speed inputs and outputs.
Power-supply decoupling capacitors should be placed
as close as possible to the V
a 75Ω transmission-line environment at the outputs, it is
necessary to minimize the parasitic capacitance by
removing the PC board ground plane from under the out-
put pins and output components. Transmission line
stubs associated with BNC connectors should be mini-
mized. Edge-mount BNC connectors are recommended.
SET
SET
given in the Typical Operating Characteristics.
SET
resistor should be placed as close as possible
values below 500Ω is not recommended.
P-P
SET
, see the graph Output Voltage Swing vs.
Applications Information
Output Voltage Swing Control
resistor connected between V
Layout Considerations
CC
connections. To support
CC
and
P-P