PCA9306: PASS GATE Connectivity Levels

Roey Tal

Prodigy 80 points

Part Number: PCA9306
Other Parts Discussed in Thread: LSF0102

Hi Team

I am working with the PCA9306 and trying to understand its operation

1. In which voltage level the NMOS stops to conduct?

Can you give an example with VPDU = 5v and VREF1=3.3v

2. If the VREF2 is related to VPDU then in case VPDU is 5v the VREF2 is 5V as well. This is the voltage of the gate of the NMOS

If VREF1 is 3.3v can you explain why the NMOS will not conduct always because Vgs is 5v-3.3v=1.7v

Thanks alot

Roey

over 1 year ago

0 Clemens Ladisch over 1 year ago

Guru 244220 points

The PCA9306 is identical with the LSF0102. See [FAQ] How do the LSF translators work?

The threshold voltage is less than 0.8 V, but not otherwise specified.

The gate voltage (EN) is about 0.6 V above VREF1; the rest of the voltage is dropped over the 200 kΩ resistor. (The connection between EN and VREF2 forms a negative feedback loop to keep the gate voltage at the threshold voltage above VREF1.)

0 Chris Ayoub over 1 year ago in reply to Clemens Ladisch

TI__Genius 15345 points

Thanks for the help on this one Clemens.

Let us know if you have any other questions Roey.

Best,

Chris

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PCA9306: PASS GATE Connectivity Levels