8 Channel Bi-directional TTL Level Shifter (HCMODU0113)

[admin]

This module uses an array of transistors with pullup resistors to provide an 8 channel bi-directional voltage level conversion (level shifting) for digital logic signals. Intended mainly for the conversion of signals between 3.3V and 5V logic levels this module provides a way of safely interfacing a 5V microcontroller to a 3.3V device or conversely 3.3V microcontroller to a 5V device without risking damage to both devices. Each of the 8 channels can also work in both directions meaning that bi-direction 2 way data signals can also be level shifted. Each side of the array can be supplied separately with the required level shifting voltage which can range anywhere between 1.8 and 6V.





Specification:

Product code: HCMODU0113
8 channel 2 way bidirectional conversion
Voltage conversion range: 1.8V to 6V
Module dimension (excluding header pins): 27.5 x 28mm




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[steve001]

HI,

Is this module suitable for I2C ?
What do you need to do with the pull up's do i need to replicate on both sides ?
if a interrupt signal has a pull up resistor do i also need to replicate this on both sides ?

The image shows right angle headers are these soldered onto the board / is it available with straight headers that can be mounted on the underside ?

Is it possible for a circuit diagram to be posted please ?

Steve

[andrew]

We've contacted the supplier but unfortunately there is no schematic available for this module.

Taking a look at the module itself it appears to be a simple circuit where each of the 8 lines has couple of FETs which are used to pull down two 10K resistors. One 10K resistor is tied to the VCCA rail, and the other to the VCCB rail. So based on this observation I don't see any reason why it wouldn't work for this purpose.

That said, depending on your application you probably don't even need level shifters. I assume you are wanting to connect two devices via I2C, one operating at 5V and the other at 3.3V levels? As the I2C interface works by using open-collector transistors to pull down a pullup resistor, so long as this pullup resistor is connected to the 3.3V rail, and your 5V device will see 3.3V as a logic high then it should work fine without level shifters.


Edit:

The image shows right angle headers are these soldered onto the board / is it available with straight headers that can be mounted on the underside ?

I'm afraid it is only available in this configuration. However there are an additional set of unsoldered pads for each connector that you can solder an additional set of header pins too.

[steve001]

Hi Andrew

Thank you,. I will my pic micro a go as you mentioned

Regards

Steve