Level Shifter Blob – Prototype Overview

Level Shifter Blob
In this post, we’re going to take a quick look at the level shifter blob prototype and cover all the information you need to use it in your projects.

Use Case:

The Piksey Pico and Nano are both 5V microcontroller boards and this results in the I/Os operating at 5V too. If you are interfacing the Pico/Nano with a 3.3V device then you will need to convert the 5V signals to 3.3V and vice-versa. This level shifter blob does just that.

Features:

It contains a built-in 3.3V low-drop-out (LDO) voltage regulator and converts the 5V to 3.3V which can be used to power the 3.3V modules. The LDO can supply a maximum of 250mA which is sufficient for most modules, but this needs to be kept in mind when interfacing external modules.

The blob uses a total of 6 MOSFETs to provide 6 bi-directional level shifters. This means that it can also be used for bi-directional communication interfaces (UART, I2C, SPI).

Wiring:

The pinout for the blob is self-explanatory but we will quickly go over it now.

Level Shifter - Voltage Sections
Level Shifter – Voltage Sections

As can be seen above, the pins to the left make up the 5V section while those on the right make up the 3.3V section. If you apply a 5V signal to bit 0 on the left, you can obtain the 3.3V version on the right. The same is true for all the other bit positions.

Here’s an image of the assembled prototype:

Level Shifter - First Prototype
Level Shifter – First Prototype
Simulation:

The following GIF illustrates the level shifting circuit and also serves as a demonstration of how the conversion takes place.

Level Shifter - Simulation GIF
Level Shifter – Simulation GIF

That’s all there is to know about the voltage level shifting blob. You can use it for just about any level shifting application you may have.