ET-A03
4-Channel Level Converter
Bidirectional 1.8–3.3 V ⇄ 3.3–5 V on four lines
AED 12.00
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Overview
Bidirectional 1.8–3.3 V ⇄ 3.3–5 V on four lines
The ET-A03 is built around the 4 bidirectional, open-drain friendly (I²C, 1-Wire, UART, SPI ≤ ~1MHz).
Designed in Dubai by ElectroTrical — the full schematic, BOM and design notes are published below.
Good for
- 5 V sensors on 3.3 V boards
- UART between 5 V and 3.3 V
- I²C across voltage domains
Key features
What makes it different
Channels
4 bidirectional, open-drain friendly (I²C, 1-Wire, UART, SPI ≤ ~1MHz)
Voltages
LV 1.8–3.3V ⇄ HV 3.3–5V; LV must be the lower rail
Parts
BSS138 N-MOSFET + 10kΩ pull-ups each side
Open documentation
Schematic, BOM and layout notes published for every board.
Breadboard friendly
Standard 2.54 mm pitch and M2.5 mounting holes.
Specifications
Technical specifications
| Channels | 4 bidirectional, open-drain friendly (I²C, 1-Wire, UART, SPI ≤ ~1MHz) |
|---|---|
| Voltages | LV 1.8–3.3V ⇄ HV 3.3–5V; LV must be the lower rail |
| Parts | BSS138 N-MOSFET + 10kΩ pull-ups each side |
| Size | 25.4 × 17.8 mm |
|---|---|
| Mounting | 4 × M2.5 holes, 2.54 mm from each corner |
| Connectors | 6-pin 2.54 mm header |
| Revision | Rev A |
Performance
Speed
Pinout
Pin map and connections
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | LV | Signal | Low voltage 1.8–3.3V (must be < HV) |
| 2 | GND | Ground | Ground |
| 3 | LV1 | Signal | LV1 |
| 4 | LV2 | Signal | LV2 |
| 5 | LV3 | Signal | LV3 |
| 6 | LV4 | Signal | LV4 |
Mechanical
Dimensions and what's in the box
In the box
- 1 × ET-A03 4-Channel Level Converter (assembled)
- 1 × 6-pin 2.54 mm male header, unsoldered
Getting started
- Wire the header: LV, GND, LV1, LV2, LV3, LV4
Compare
Which I/O expander?
| 4-Channel Level Converter (this board)This board | ET-A04 MCP23017 16-Bit I/O Expander | ET-A07 PCF8574 8-Bit I/O Expander | |
|---|---|---|---|
| What it does | Bidirectional 1.8–3.3 V ⇄ 3.3–5 V on four lines | Sixteen extra GPIO pins over I²C, Qwiic | Eight extra GPIO pins over I²C, Qwiic |
| Interface | — | I²C up to 1.7MHz, 0x20 (0x20–0x27 via jumpers →… | I²C 100kHz, 0x20 (0x20–0x27 via jumpers); Qwiic /… |
| Best for | 5 V sensors on 3.3 V boards | Button panels and keypads | A few extra buttons or LEDs |
| Price | 12 AED | 19 AED | 14 AED |
Downloads
Documents and design files
PDFET-A03 schematicRev A
STEP3D modelComing soon
Need a custom version of this board?
Different connector, size or sensor? We design and build custom variants.