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.
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.
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).
The pinout for the blob is self-explanatory but we will quickly go over it now.
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:
The following GIF illustrates the level shifting circuit and also serves as a demonstration of how the conversion takes place.
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.