The small company EzSBC offers specialized unidirectional level shifters designed for microcontrollers to interact with systems up to 18V (e.g., 12V automotive electronics).
The maker claims this level shifter can “easily translate a 1MHz signal”.
Overview
Most mainstream level shifters support only a limited voltage range, targeting microcontrollers and sensors running below 6V.
The level shifters discussed here are based on CD4504B ICs and support a wide voltage range from 3.3-18V on both sides. There are no restrictions on which side must have a higher voltage.
Controlling Up To 18V Systems
EzSBC’s level shifters support 3.3-18V inputs and outputs. Input voltage signals can be higher or lower than the output signals (however, all inputs must share the same voltage, and all outputs must share the same voltage). That is why pins on the board are marked input and output, not low and high.
For example:
- If you place the low-voltage microcontroller on the input side, it can send information to the high-voltage system.
- If you place the high-voltage system on the input side instead, the microcontroller can receive (read) information from the other system.
Unidirectional
Communication is one-way (unidirectional): one side can always send (but not receive), and the other side can always receive (but never send).
Semi-Bidirectional
If you need to send and receive—such as controlling external systems (sending commands) and also verifying their status (receiving GPIO state)—you must use two level shifters, with your microcontroller on the input side of one and the output side of the other.
Since this is cumbersome, EzSBC also offers a variant level shifter implementing 2x6 channels: six for inputs, six for outputs.
- LS2: 12 unidirectional channels
- LS3: 6 channels in one direction, plus 6 channels in the opposite direction
LS2 – 12 Unidirectional Channels
The original LS2 level shifter provides 12 channels for unidirectional data transfer between voltage domains:
| Pin | Description |
|---|---|
Vi |
Positive voltage of input system (3.3-18V) |
Vo |
Positive voltage of output system (3.3-18V) |
In1-In12 |
12 input channels |
O1-O12 |
12 output channels |
Gnd |
Common ground |
The inputs have 500kΩ resistors to ground; unused inputs may be left unconnected. When the input is not driven high, the corresponding output pin will be low. The output swings close to ground and to the configured output voltage.
LS3 – 2x6 Channels
The LS3 variant works like LS2 but offers six inputs and six outputs per voltage domain:
This board is organized around two voltage domains, labeled “low” and “high” (Vlo and Vhi).
Both “low” and “high” support the 3.3-18V range; either side can be connected to the higher or lower voltage.
| Pin | Description |
|---|---|
Vlo |
Positive voltage of input system (3.3-18V) |
Vhi |
Positive voltage of output system (3.3-18V) |
InLo1-InLo6 |
6 input channels on “low” voltage domain |
OLo1-OLo6 |
6 output channels on “low” voltage domain |
OHi1-OHi6 |
6 output channels on “high” voltage domain |
InHi1-InHi6 |
6 input channels on “high” voltage domain |
Gnd |
Common ground |
What About LS1?
Is there also an LS1 level shifter? Yes, there was. LS1 was EzSBC’s original design: an 8-channel bidirectional I2C level shifter, initially sold via tindie.com. Its main feature was broad voltage independence, supporting up to 12V.
This product appears to be discontinued. More background information is available from the original maker.
How It Works
LS2 and LS3 use two CMOS CD4504B hex voltage level shifter ICs from Texas Instruments; each chip provides six channels to shift signals between different voltages.
LS2 uses both chips for the same direction, giving 12 unidirectional channels. LS3 uses one chip per direction, providing 6 channels in each direction.
According to the official datasheet, the chip supply voltage is 5-18V. However, this datasheet dates back to 2004 when 5V microcontrollers were more typical. Recent discussion in Texas Instruments forums suggests use at 3.3V may be possible, although threshold voltages and timing specs are not guaranteed below 5V.
In practice, for slow signal translation, these level shifters usually work fine at voltages even below 5V, but optimal performance is not guaranteed in all scenarios.
Materials
Slow Website?
This website is very fast, and pages should appear instantly. If this site is slow for you, then your routing may be messed up, and this issue does not only affect done.land, but potentially a few other websites and downloads as well. Here are simple steps to speed up your Internet experience and fix issues with slow websites and downloads..
Comments
Please do leave comments below. I am using utteran.ce, an open-source and ad-free light-weight commenting system.
Here is how your comments are stored
Whenever you leave a comment, a new github issue is created on your behalf.
-
All comments become trackable issues in the Github Issues section, and I (and you) can follow up on them.
-
There is no third-party provider, no disrupting ads, and everything remains transparent inside github.
Github Users Yes, Spammers No
To keep spammers out and comments attributable, all you do is log in using your (free) github account and grant utteranc.es the permission to submit issues on your behalf.
If you don’t have a github account yet, go get yourself one - it’s free and simple.
If for any reason you do not feel comfortable with letting the commenting system submit issues for you, then visit Github Issues directly, i.e. by clicking the red button Submit Issue at the bottom of each page, and submit your issue manually. You control everything.
Discussions
For chit-chat and quick questions, feel free to visit and participate in Discussions. They work much like classic forums or bulletin boards. Just keep in mind: your valued input isn’t equally well trackable there.
(content created Jul 21, 2025)