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TS3A27518E-Q1: will the data rate be same as mentioned in the datasheet if am operating the device at an ambient temperature of -40 to 105

Part Number: TS3A27518E-Q1

Hi

I am planning to use TS3A27518ETRTWRQ1.

I wanted to check will the data rate be same as mentioned in the datasheet if am operating the device at an ambient temperature of -40 to 105.

How Ron is related to bandwidth. Is there any calculation.

Regards

Nitesh

  • Hello Nitesh,

    As the max data rate is directly related to bandwidth, the max frequency data can be passed through the TS3A27518E-Q1 operated at 3.3V at 25C will typically be 240 MHz.  However as you suspected, bandwidth varies with Ron and Ron varies with operating voltage and temperature. For determining Ron for your particular use case, you can estimate this with some of the figures posted in the datasheet (figures 1A, B, and C).  

    Figures 1

    Once you have determined an Ron value through interpolation or estimation that is reasonable for your conditions, you can extract the bandwidth through a basic simulation.  At frequencies under 500 MHz a switch can be approximated with the circuit shown in figure 2.  From this figure you can see that Ron with the parasitic input/output capacitors forms a low pass filter.  Specifications for Ron and I/O capacitance can be found for certain specified conditions in the datasheet seen in table 1. Between devices as well as with different voltages and temperatures, there will be deviations. From these values you can begin to put together a basic model in LTspice, TINA, or other spice simulator of your choice.  However, one additional detail you will need to include is the influence of the series and load resistors that were present during the measurement of the bandwidth(figure 3).  During calibration of the VNA the insertion loss of the VNA and the leads to device will be removed, but these resistors will still contribute to the filter during the bandwidth measurement.  So with the above passives in place, the AC transfer characteristic can be plotted (figure 4).  If we look at 3 dB below the insertion loss of -6.39dB, we see that the bandwidth is around 294 MHz.  You may subsequently question why this does not match the 240 MHz listed in the datasheet.  As stated previously, this is an approximation and a more accurate model would include more poles from smaller parasitic capacitors as well as zeros from inductors modeling your bondwire.

    Figure 2

    Table 1

    Figure 3

    Figure 4

  • Hi
    I have supply voltage and Control pins at level 3.3V for TS3A27518E-Q1 then can i transmit the signals with 1.8V level from Common to NC or NO.
    Do you have any general power calculation method for the switch and muxes

    Regards
    Nitesh
  • Nitesh,

    I found this post searching the forum for power calculation that may help. 

    Thank you,

    Adam

  • Hi Adam

    Thanks for reply...

    Can you please mention like if I have supply voltage and Control pins at level 3.3V for TS3A27518E-Q1 then can i transmit the signals with 1.8V level from Common to NC or NO.

    Regards

    Nitesh

  • Nitesh,

    The TS3A27518E-Q1 is a passive FET switch and it doesn't have current drive capability it will simply pass a signal of any voltage you place on the signal between 0 V and Vcc.  That means you need to set Vcc voltage higher than the signal voltage you would like to pass through the device. 

    Thank you,

    Adam