TS5A22362: In and output impedance

Dries Vandenberk

Prodigy 40 points

Part Number: TS5A22362

What are the in and output impedances of these switches?

I cant seem to find them.

Kind regards

Dries

over 6 years ago

0 Adam Torma over 6 years ago

TI__Mastermind 45370 points

Dries,

Please read that switches FAQ in the forum and this appnote to learn that these are passive FET switches. Specifically the TS5A22362 is a bilateral switch or transmission gate FET switch. The impedance of the switch will be the on-state resistance and onstate capacitance of the switch which is specified in the datasheet.

What is your concern with the input impedance?

Thank you,

Adam

0 nazim zmirli over 6 years ago in reply to Adam Torma

Prodigy 20 points

Analog switches are extensively used for switching audio signals in battery-powered applications, such as mobile phones. In any cases, the switch is powered directly from the battery, but it receives control signals from a lower voltage processor GPIO.

0 Dries Vandenberk over 6 years ago in reply to Adam Torma

Prodigy 40 points

I want to use the switch to pass catheter signals to a ECG recording device and that requires impedance matching to prevent signal loss.

0 Adam Torma over 6 years ago in reply to Dries Vandenberk

TI__Mastermind 45370 points

Dries,

The impedance of the switch will be the series resistance and parallel capacitance of the internal FET. The FETs are not linear and will vary slightly based on frequency and input voltage. This device has very low series resistance < 1 ohm and you will not encounter much voltage loss across the part.

I'm not sure of the frequency content in the catheter signals you want to capture but this device will only pass frequency content of the signal that is <17 MHz.

Thank you,
Adam

0 Dries Vandenberk over 6 years ago in reply to Adam Torma

Prodigy 40 points

Hi Adam

Thank you for the information!
The frequency will be <<1MHz, do you know if this will have any effect if my catheter has a low output impedance?

Thank you
Dries

0 Adam Torma over 6 years ago in reply to Dries Vandenberk

TI__Mastermind 45370 points

Dries,

The effect of the signal switch will be slight attenuation of your signal due to the on-state resistance and on-state capacitance <-0.5 dB

Thank you,

Adam

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TS5A22362: In and output impedance