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CD4053B: How to speed up fall time

Ryotaro Fukui
Intellectual 2345 points
Part Number: CD4053B
Other Parts Discussed in Thread: TMUX6219, TMUX7209, TMUX6211

Hello team,

I received a question from my customer about the specifications of the CD4053BPWR.

They would like the output signal to have a fall time of 400ns when the input signal of the CD4053BPWR changes from high to low, and I would like to know how they could speed up the fall time.

In addition, if TI has a switch IC that can be used with the following specifications in addition to the CD4053B, we would appreciate if you could introduce it.

- Supply voltage: 18V (required)

- Input signal: 14V (required)

- Output signal falling time within 400 ns (if possible)

If there are additional customer system information needed for the answer, please contact us.

Best Regards,
Ryotaro Fukui

  • 0
    Guru 272510 points

    This switch does not actively drive the output signals; it behaves like a 125 Ω resistor.

    You should get faster speeds with a switch with lower on-resistance, like the TMUX6219.

  • +1
    TI__Genius 10974 points

    Hi Ryotaro,

    The only way they could help speed up the fall time would be decreasing the resistance or capacitance (or both) of what is connected to the output of the device. Besides that, the part that Clemens mentioned (the TMUX6219) would also be a good fit for this application as it has much lower on resistance (however, slightly higher on capacitance) than the CD4053 and has a maximum fall time of 250ns (under the specified loading conditions of 300 ohms and 35pF).

    Thanks!

    Bryan

  • 0 in reply to Bryan Marshall
    TI__Intellectual 2345 points

    Hi Bryan, Clemens,

    Thank you for all your comments. I received a feedback from the customer.

    Thank you for the information about how to reduce falling time without changing the device. They also reviewed the proposed TMUX6219 data sheet and confirmed that the specifications satisfies their usage.

    For additional question, is there an IC with three elements, such as CD4053B, as per the TMUX6219 specification? In order to reduce the mounting space, they want to implement a three-element IC instead of three TMUX6219.

    Also, if you have an IC with an on-resistance of around 60 Ω, would you be able to introduce it too?

    Best Regards,
    Ryotaro Fukui

  • 0 in reply to Ryotaro Fukui
    Guru 272510 points

    The CD4053B is the only 18 V switch with at least three channels.

    The only two-channel switch with less than 125 Ω is the TMUX7209.

  • +1 in reply to Ryotaro Fukui
    TI__Genius 10974 points

    Hi Ryotaro,

    We do not have another 3 channel device that can support the voltage range you require. However, depending on what your exact circuit looks like, you can try to look into the TMUX6211/6212/6213 family to try to make something work with that. These are 1:1x4 channel switches with different logic configurations, low RON, and less than 300ns fall time.

    Thanks!

    Bryan

  • 0 in reply to Bryan Marshall
    TI__Intellectual 2345 points

    Hi Bryan,

    I received a response from the customer.

    They understood that there were no devices with exact specifications, but I would like to consider the devices you have introduced to us.

    Thank you for introducing all the recommended devices.

    Best Regards,

    Ryotaro Fukui