MAX3946ETG+T Maxim Integrated Products, MAX3946ETG+T Datasheet - Page 25

• Manufacturer Part Number: MAX3946ETG+T
• Description: IC LASER DVR SFP 11.3GBPS 24TQFN
• Manufacturer: Maxim Integrated Products
• Type: Laser Diode Driverr

Specifications of MAX3946ETG+T

• Data Rate: 11.3Gbps
• Number Of Channels: 1
• Voltage - Supply: 2.85 V ~ 3.63 V
• Current - Supply: 68mA
• Current - Modulation: 80mA
• Current - Bias: 80mA
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 12-WFQFN, Exposed Pad
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 6. Simplified I/O Structures
The data inputs and outputs are the most critical paths
for the device and great care should be taken to mini-
mize discontinuities on these transmission lines between
the connector and the IC. Here are some suggestions for
maximizing the performance of the IC:
• The data inputs should be wired directly between the
• The data transmission lines to the laser should be kept
• An uninterrupted ground plane should be positioned
• Ground path vias should be placed close to the IC and
cable connector and IC without stubs.
as short as possible and be designed for 50I differ-
ential or 25I single-ended characteristic impedance.
beneath the high-speed I/Os.
the input/output interfaces to allow a return current
path to the IC and the laser.
DISABLE
1.0625Gbps to 11.3Gbps, SFP+ Laser Driver
V
V
with Laser Impedance Mismatch Tolerance
CCT
EET
7.5kI
______________________________________________________________________________________
TIN+
TIN-
Layout Considerations
50I
50I
V
CCT
V
EET
CONTROL
LOOP
CLAMP
V
EET
FAULT
DEEMPHASIS
• Maintain 100I differential transmission line imped-
• Use good high-frequency layout techniques and mul-
Refer to the schematic and board layers of the MAX3946
Evaluation Kit (MAX3946EVKIT) for more information.
The exposed pad on the 24-pin TQFN provides a very
low-thermal resistance path for heat removal from the IC.
The pad is also electrical ground on the IC and must be
soldered to the circuit board ground for proper thermal
and electrical performance. Refer to Application Note 862:
HFAN-08.1: Thermal Considerations of QFN and Other
Exposed-Paddle Packages for additional information.
SDA
CONTROL
ance into the IC.
tilayer boards with an uninterrupted ground plane to
minimize EMI and crosstalk.
V
V
CCD
EET
75kI
25I
V
EET
25I
Exposed-Pad Package and
V
CCT
Thermal Considerations
SCL, CSEL
V
V
TOUT+
TOUT-
CCD
EET
75kI
25