DS110DF410: PIN setting

Hi team,

I have one more question.

4)The datasheet states, "For SMBus slave mode, the READ_EN pin must be tied low. Do not leave it floating or tie it high." Is a pull-down resistor required for the READ_EN pin? If so, what should be the resistance value?

Sincerely,

Naoki Yoneyama

Hello Yoneyama-san,

Thank you for posting your inquiry on the DS110DF410.

An engineer has been assigned to this thread. Please allow them to review this inquiry and provide feedback by the middle of this week.

Best,
David

Hi Naoki-san,

Naoki Yoneyama said:

When using the DS110DF410 with the CDR bypassed, is it necessary to input a reference clock? In that case, can the REFCLK_IN/OUT pins be left open?

We have not validated that.

Naoki Yoneyama said:

2) If only channel 0 is used, can the RXP/N, TXP/N, LPF_CP, and LPF_REF pins for channels 1, 2, and 3 be left open?

If the input is not used it is best to terminate it. 

Naoki Yoneyama said:

3) The pin description for LPF_CP and LPF_REF in the datasheet states, "Place a 22 nF ± 10% Capacitor between LPF_CP_0 and LPF_REF_0." On the other hand, the EVK allows these two pins to be shorted. In what situations should they be shorted?

The loop filter pins set the jitter bandwidth for the CDR. The capacitor restricts the CDR jitter tolerance. This is not relevant for your application.

Naoki Yoneyama said:

4)The datasheet states, "For SMBus slave mode, the READ_EN pin must be tied low. Do not leave it floating or tie it high." Is a pull-down resistor required for the READ_EN pin? If so, what should be the resistance value?

It can be tied directly to GND.

Best regards,

Nick