4-channel I2C-safe Bi-directional Logic Level Converter - BS

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weswitt
 
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4-channel I2C-safe Bi-directional Logic Level Converter - BS

Post by weswitt »

I'm seeing a problem with one of these: https://www.adafruit.com/product/757

I've used these many times before and never had a problem so this is a but confusing.

My connections are as follows: +5V to HV, 3V3 to LV, TX signal from an Uno to B1, GND to GND.

What I'm seeing is a 3V3 signal on all low voltage pins A1, A2, A3, A4.

What I should see is a 3V3 signal only on A1. There are NO shorts across any of the pins.

Is this a bad board?
Breakout board
Breakout board
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adafruit_support_mike
 
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Re: 4-channel I2C-safe Bi-directional Logic Level Converter

Post by adafruit_support_mike »

The transistors have pull-up resistors on both input and output, so it's normal for the line to default to HIGH with no other input. That's where an I2C bus is supposed to go when it's idle, actually.

Do the voltages on A2, A3, and A4 change when you change the voltage at A1?

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