This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TINA/Spice/CD4052B: Looking for SPICE model for the device

Part Number: CD4052B
Other Parts Discussed in Thread: TINA-TI,

Tool/software: TINA-TI or Spice Models

Hi,

Are SPICE models available for the CD4052B? If not, what is close or could be modified to work with?

Thanks...

  • Hi David, 

    We don't have SPICE model of CD4052B. For a simple 4:1 differential switch, I would use the following RC circuit. The component value is from CD4052B datasheet.

  • Thanks very much, that should work for my application, I will use the simple model you propose. 

    I was most interested in understanding the series resistance matching between the channels and between parts, as that will introduce error in my analog chain.  125 Ohm nominal to 240 Ohm max is a large variance.  Any suggestions on how best to account for that error? I have already followed the device with a very high input impedance instrumentation amplifier .

  • Hi David,

    The series resistance between channels is what we called Delta Ron. For CD405x family, Delta Ron is around 5 Ohms when supply is 15V. It shouldn't matter in your system because the following stage is instrumentation opAmp. Most instrumentation opAmps have typically 1 GOhm input resistance.

    The series resistance of one single channel is what we called Ron, 125 Ohms typical for CD405x family. Its variation is not mainly due to part to part variation.  It is a function of input voltage and supply voltage. Here I capture the Ron curve vs input voltage and supply voltage.

    Even if your input signal range is, for example, 0~10V, it is also recommended to supply this device with higher voltage, 15V for example. Ron flatness will be beneficial. 

    Another trick you may consider is adding a1k ~ 2k Ohm resistor in front of CD405x.

    First, it can help filter external high-frequency noise.

    Second, it can increase the system reliability because if there is a fast high transient event at the analog input pin, this resistor can be current limiting. 

    Third, it can help further mitigate the Ron variation effect. Assume the resistance from system input to instrumentation opAmp is 1k + switch Ron. The variation of switch Ron will play a smaller factor since the variation percentage now will be (Ron variation) / (1k + switch Ron typical). 

    Please also keep in mind, the added resistor cannot be significantly high due to its bandwidth limiting and thermal noise from the added resistor itself.