SN65HVD75: current consumption

Shanoj G

Part Number: SN65HVD75
Other Parts Discussed in Thread: SN65HVD11,

Hi,

In my design RS485 half duplex communication has SN65HVD75 is at one end and SN65HVD11 on the other end. The termination resitstor between Rx and Lx is 136 ohm at both end. Baud rate is 921600 and the cable length is about 8 meters. Can you help me on estimating current drawn by SN65HVD75 in this design. Please share if any supporting document justifying the calculations.

Thanks

Shanoj

over 6 years ago

0 Hao L over 6 years ago

TI__Mastermind 25705 points

Shanoj,

You can refer to this article for the power dissipation estimate.

e2e.ti.com/.../how-to-calculate-the-power-dissipation-of-high-speed-rs-485-transceivers

For your application, since the data rate is not high, the major power comes from the resistive load (136/2=68Ohm). After you measure the bus voltage, the output current is known. Then SN65HVD75 power dissipation can be obtained by taking care of the load resistor power.

Regards,

Hao

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SN65HVD75: current consumption