JAJSFL5D April 2016 – June 2018 LMH1219
PRODUCTION DATA.
DESIGN PARAMETER | REQUIREMENTS |
---|---|
IN0+ Input AC coupling capacitor | AC Coupling capacitor at IN0+ should be a 4.7-μF capacitor. Choose a small 0402 surface mount ceramic capacitor. IN0- should be AC terminated with 4.7 μF and 75 Ω to VSS. |
IN1± Input AC coupling capacitors | AC Coupling capacitors at IN1± should be 4.7-μF capacitors. Choose small 0402 surface mount ceramic capacitors. This allows both SMPTE and 10 GbE data traffic. |
Output AC coupling capacitors | Both OUT0± and OUT1± require AC coupling capacitors. Choose small 0402 surface mount ceramic capacitors. 4.7-μF AC coupling capacitors are recommended. |
DC power supply decoupling capacitors | Decoupling capacitors are required to minimize power supply noise. Place 10-μF and 1-μF bulk capacitors close to each device. Place a 0.1-μF capacitor close to each supply pin. |
VDD_LDO decoupling capacitors | Place 1-μF and 0.1-μF surface mount ceramic capacitors as close as possible to the device VDD_LDO pin. |
High speed board trace for IN0 | IN0+ and IN0- should be routed with uncoupled board traces with 75-Ω characteristic impedance. |
High Speed IN1, OUT0, and OUT1 trace impedance | IN1±, OUT0± and OUT1± should be routed with coupled board traces with 100-Ω differential impedance. |
SMPTE return loss | Place BNC within 1 inch of the LMH1219 and consult BNC vendor for recommended BNC landing pattern to meet SMPTE requirements. |
IN0+ and IN1± cross talk | When a long length coax cable is connected to IN0+, the signal amplitude at IN0+ can be just a few mVp-p. Layout precautions must be taken to minimize crosstalk from adjacent devices or from adjacent input port IN1±. To reduce cross coupling effects, keep IN1± traces as far from IN0± as possible. When IN1± is not used, it is recommended to turn off the signal source to IN1± for best results. |
Use of SPI or SMBus interface | Set MODE_SEL to Level-F (pin unconnected) for SPI. Set MODE_SEL to Level-L (connect 1 kΩ to VSS) for SMBus. SMBus is 3.3 V tolerant. |