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LMX2615-SP: LMX2615-SP OSCinP/OSCinM Differential Swing & Voltage

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Part Number: LMX2615-SP

LMX2615-SP Datasheet Observations:

1.) On Pg 8, Table 6.5: Voscin=0.4Vpp to 2Vpp for Single Ended AC Coupled sine wave, Complimentary Side grounded with 50 ohm resistor thru ac coupling cap, Foscin>20MHz.

2.) On Pg 55, Figure 69 Differential Waveform shows Voscin=Single Ended Swing of Differential Waveform.

Questions:

1.) Does the Voscin-min spec. of 0.4Vpp from Table 6.5 apply as shown on the Differential Waveform in FIgure 69?  Such that when OSCinP/OSCinM is driven deferentially the Minimum Differential peak to peak swing is: 2x(Single_Ended_Swing)=2x0.4Vpp_single_ended=0.8Vpp_differential?

    a.) If yes, LVDS is not guaranteed to meet this minimum swing requirement so why is it recommended on Pg 55 of the datasheet in section 8.1.2.

    b.) if no, can you please specify the min & max for both the differential voltage and differential swing (2xDifferenetial Voltage) for the OSCinP/OSCinM input pair when Foscin>20MHz

For your reference the LMK04832-sp datasheet pg 15, section 7.2 has a very good discussion of this common confusion, and how to disambiguate it. Feel free to use the terminology from that reference when responding.

Thank you, John

  • Hi John,

    If only one of the OSCin pins is used, then the input voltage swing should be between 0.4Vpp to 2Vpp. 

    If both pins are used, the input voltage swing at each pin should be 0.2Vpp to 1Vpp, so no problem with a LVDS input.