LMX2571EVM: Difference between part and EVM power supply

Eyal Rub

Part Number: LMX2571EVM
Other Parts Discussed in Thread: LMX2571, USB2ANY

Hey E2E support,

I have a customer with a question regarding the LMX2571EVM,

In the LMX2571 datasheet it is stated that the supply voltage while working with the SPI digital interface is 3.3 volts.

However in the EVM schematic, a resistor divider (10k/12k) is used to convert the 3.3 logic from USB2ANY interface adapter down to 1.8V at LMX25731 SPI/Microwire input.

Is there a reason for this difference ?

Thank you for your help !

- Eyal

over 3 years ago

0 Derek Payne over 3 years ago

TI__Mastermind 29830 points

Hi Eyal,

Historically, this EVM communicated using uWire interface, which was connected to a PC LPT. The parallel port interface was 5V, and we picked convenient values to drop the 5V signal from the host PC to an acceptable level for the device. Now that USB2ANY is the provided programming solution, the divider can be safely omitted without impacting communication capability.

Regards,

0 Eyal Rub over 3 years ago in reply to Derek Payne

TI__Intellectual 845 points

Hey Derek,

This is very insightful !

Thank you for your quick response and happy holidays !

- Eyal

Clock & timing

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LMX2571EVM: Difference between part and EVM power supply