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THS3121 / OUTPUT VOLTAGE vs LOAD RESISTANCE under VS=±5V

K.Yaita
Guru 29720 points
Other Parts Discussed in Thread: THS3121

Hi Team,

My customer considers to use THS3121 for his application.
He wants to get the graph "OUTPUT VOLTAGE vs LOAD RESISTANCE" under VS=±5V.
*Figure 19 is under VS=±15V.



Do you have the data (graph)?

Best Regards,
Yaita / Japan disty

  • 0
    TI__Genius 12631 points
    Hello Yaita-san,
    I just checked the archives and I cannot find any data on the THS3121 at +/-5V supplies. This is a very old device so the data doesn't seem to be on our standard archive systems.

    -Samir
  • 0 in reply to Samir Cherian
    Guru 29720 points

    Hi Samir-san,

    Thank you for confirming.
    I would like to ask one more.

    Does output voltage under VS=±5V show one third of that of under VS=±15V in Figure19?
    I would like to ask if Figure19 could be applied to output voltage under VS=±5V in view of above.

    Best Regards,
    Yaita

  • 0 in reply to K.Yaita
    TI__Genius 12631 points
    Yaita-san,
    There are a couple of things we can do to project performance at +/-5V supplies vs +/-15V supplies.

    1. On page 4 the typical output swing for two given load conditions (1k and 50ohm) is +/-14V and +/-13.5V....so 1V and 1.5V from each rail. For the same load conditions at +/-5V supplies, on page 6 output conditions the swing is +/-1V and +/-1.1V. This tells me the part works very well at +/-5V. So we can use than information and figure 19 to extrapolate information. Figure 19 was taken as a slam test so while the amplifier can certainly drive those loads, it should be noted that the graph tells us nothing about the amplifiers linearity.

    2. To compare the amplifiers linearity performance: For +/-15V supplies, Figure 9 and 10 show the distortion performance at 1MHz, 2Vpp sinusoidal signal to be -75dBc and -78dBc respectively. For the same conditions Figures 37 and 38 at +/-5V show the performance to be -72 and -75dBc respectively. This suggests little signal degradation as supplies are varied.

    What is the customer application? How much output swing, load, bandwidth are they looking at? How about gain configuration?

    -Samir
  • 0 in reply to Samir Cherian
    Guru 29720 points

    Hi Samir-san,

    Thank you for your comments.
    My customer is just studying the device at this time.
    If I get any information, I will inform you about it. 

    Best Regards,
    Yaita