LMP90100 Schematic Design

Joerg,

I took a look at your circuit and it looks reasonable to me. I'm assuming the resistor ladder  (R1, R2, R3) in parallel to the load cell connectors is intentional. I've forwarded to the responsible Applications Engineer in case he has any further input.

Note a possible delay due to the Holidays.

These are the parts of the Schematic "LMP90100 EVB User’s Guide"  snau028a.pdf

Delay is no Problem.

Joerg

Yes Joerg a similar resistor divider is included on the LMP90100 evaluation board. The intent of this resistor divider is to set the input to a known voltage level for testing and calibration. My concern though is if this resitor divider is left in parallel to your Wheatstone bridge load cell then you will get unexpected output voltage from the load cell. Like the evaluation board you should have a jumper (i.e. JP10) to allow the user to connect to the resistor divider OR the load cell, not both at the same time.

Hallo Jason,

thank You for Your reply.

What do You think about to place Capacitors and Resistors in the Input Lines ?

regards

Joerg

Joerg,

It's not a bad idea to have place holders for caps and resistors as you've shown. Depending on your sensing needs these can be used for filtering. But if they negatively impact performance this allows you to remove the caps and short the reistors.

Just one more Question.

What to do with Xin and Xout ? Leave them open , short to ground or couple with capacitor to ground?

regards

Joerg

If you plan to use the internal clock (CLK_SEL = 0) you can leave Xin and Xout open.