LMH0303 Datasheet, PDF (18/27 Pages) National Semiconductor (TI) – 3 Gbps HD/SD SDI Cable Driver with Cable Detect

LMH0303
SNLS285H – APRIL 2008 – REVISED MAY 2016
www.ti.com
8.2.2 Detailed Design Procedure
The following design procedure is recommended:
1. Select a suitable power supply voltage for the LMH0303. It can be powered from a single 3.3-V supply (see
Power Supply Recommendations).
2. Check that the power supply meets the DC requirements in Recommended Operating Conditions.
3. Select the proper pull-high or pull-low for SD/HD to set the slew rate.
4. Select proper pull-high or pull-low for ENABLE to enable or disable the output driver.
5. Choose a high quality 75-Ω BNC that is capable to support 2.97-Gbps applications. Consult a BNC supplier
regarding insertion loss, impedance specifications, and recommended BNC footprint for meeting SMPTE
return loss requirements.
6. Choose small 0402 surface mount ceramic capacitors for the AC-coupling and bypass capacitors.
7. Use proper footprint for BNC and AC-coupling capacitors. Anti-pads are commonly used in power and
ground planes under these landing pads to achieve optimum return loss.
8.2.3 Application Curves
1 ns/DIV
Figure 6. SDO PRBS10 at 270 Mbps
920
900
880
860
840
820
800
780
760
660
680
700
720
740
760
780
R_REF Resistance (Ÿ)
C001
Figure 7. SDO Amplitude vs R_REF Resistance
9 Power Supply Recommendations
Follow these general guidelines when designing the power supply:
1. The power supply should be designed to provide the recommended operating conditions (see
Recommended Operating Conditions).
2. The maximum current draw for the LMH0303 is provided in Electrical Characteristics – DC. This figure can
be used to calculate the maximum current the supply must provide.
3. The LMH0303 does not require any special power supply filtering, provided the recommended operating
conditions are met. Only standard supply coupling is required.
18
Submit Documentation Feedback
Product Folder Links: LMH0303
Copyright © 2008–2016, Texas Instruments Incorporated