LMX2572: DIGITAL INTERFACE WORKING CONDITION

Aravind D

Prodigy 70 points

Part Number: LMX2572

Hi,

We are using LMX2572 in our design and all the supply pins are provided with 3.3V

Unfortunately only 1.8V banks are available in our FPGA, so SCK and SDI pins are connected to 1.8V bank of FPGA.

As per datasheet VIH and VIL as given below supports 1.8V for digital input signals.

whether this will work or i need to connect SCK and SDI to 3.3V only?

Kindly clarify!

Thanks & regards,

Aravind D

over 4 years ago

0 Noel Fung over 4 years ago

TI__Guru** 119760 points

Hi Aravind,

1.8V from FPGA is higher than the min. VIH requirement of 1.4V, so there is no problem with direct connection.

However, MUXout (lock detect or serial data output) output is 3.3V, you need to voltage-divide it down to 1.8V before connecting to the FPGA.

0 Aravind D over 4 years ago in reply to Noel Fung

Prodigy 70 points

Hi Noel Fung,

Thanks for the clarification!

So irrespective of whatever our supply voltage is, we can rely on the digital interface specification from datasheet for digital input or output signals, is that rite?

Yes for MUXOUT I have used a bidirectional level translator.

Regards,

Aravind D

0 Noel Fung over 4 years ago in reply to Aravind D

TI__Guru** 119760 points

That's right.

Clock & timing

Clock & timing forum

LMX2572: DIGITAL INTERFACE WORKING CONDITION