A single-supply logic-level shifter can translate between different logic-voltage domains without a second supply rail for the translator. That can remove a power connection, decoupling needs, and sequencing concerns—but it does not make every 1.8 V, 3.3 V, and 5 V combination compatible. Choose the part by signal direction, bus type, voltage limits, thresholds, speed, and what happens when one device is off.
What “single-supply” means
A level shifter changes the voltage levels used to represent logic signals between connected devices. A single-supply translator uses one supply for the translator itself, rather than requiring separate low- and high-voltage rails. Texas Instruments states that “For level translation up and down, the LVxT family requires only a single power supply.” See TI’s SN74LV4T125 datasheet.
The practical benefit is a simpler power architecture: there is no dedicated second translator rail to route, decouple, and sequence. The devices on either side still operate in their own voltage domains, and the translator must have suitable input thresholds, output levels, and voltage ratings for both.
Choose the translator architecture for the signal
Fixed-direction buffers and gates
For signals that always travel one way, a fixed-direction part can be a compact choice. TI describes the SN74LV1T34 as a single-power-supply, single-buffer CMOS logic-level shifter. The SN74LV1T04 is a single inverter with reduced input thresholds intended for translation, so use it only when inverted logic is acceptable. The SN74LV4T125 provides four buffered channels with three-state outputs.
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#1 Best Overall
- The bi-directional logic level converter is a small device that safely steps down 5V signals to 3.3V and steps up 3.3V to 5V at the same time
- Each logic level converter has the capability of converting 4 pins on the high side to 4 pins on the low side with two inputs and two outputs provided for each side
- 3.It can bidirectionally transfer with 4 channels between high logic voltage and low logic voltage
Auto-bidirectional translators for suitable buses
For buses where either side may pull a signal low, an auto-bidirectional/open-drain translator may avoid a direction-control pin. TI’s LSF0102 datasheet shows a single 3.3 V supply translating between a 3.3 V device and a device whose voltage can vary from 1.8 V to 5.0 V, using resistors in place of the second supply. The datasheet warns that current from Vref_A affects the network, so it must not be treated as a simple voltage divider; follow its reference-bias equations and circuit guidance.
Dual-supply bidirectional transceivers
If the application needs explicit low- and high-side supplies or push-pull bidirectional signaling, a dual-supply transceiver may fit better, though it gives up the one-rail simplicity. Analog Devices’ MAX13046E/MAX13047E documentation describes single- or dual-channel bidirectional translation, operation down to 1.1 V on VL, shutdown control, and ESD protection.
Rank #2
- Level Shifter Converter：Realize bidirectional level conversion between 3.3V and 5V voltage domains to ensure that devices or modules in different voltage domains can communicate normally
- Input voltage: supports 3.3V and 5V input voltages
- Output voltage: automatically adjusts according to the input voltage to achieve 3.3V to 5V or 5V to 3.3V conversion
- Compatibility: Compatible with various digital signal interfaces, such as I2C, SPI, UART, etc
- Multiple channels: 4 channels
Compare the relevant options
| Option | Direction and channel notes | Power approach | Key consideration |
| SN74LV1T34 | Single buffer; fixed-direction use | Single supply | Verify thresholds, output levels, and package details for the exact part. |
| SN74LV1T04 | Single inverter; fixed-direction use | VCC options documented at 5.0 V, 3.3 V, 2.5 V, and 1.8 V in TI’s 2024 product documentation | Inverts the signal; confirm that is compatible with the logic design. |
| SN74LV4T125 | Four buffered channels with three-state outputs | Single supply | Check output-enable behavior and timing along with the electrical limits. |
| LSF0102 | Auto-bidirectional/open-drain style | Single-supply configuration is shown in TI’s datasheet | Use the datasheet’s reference-bias method; a simple divider model is insufficient. |
| MAX13046E/MAX13047E | Single- or dual-channel bidirectional | Dual-supply capability | More supply flexibility; confirm the specified operating conditions for the desired rate. |
Analog Devices’ 2021 product documentation specifies guaranteed push-pull rates of 8 Mbps for 1.2 V ≤ VL ≤ 3.6 V with VCC ≤ 5.5 V, and 16 Mbps for 1.8 V ≤ VL ≤ VCC ≤ 3.3 V. It also specifies a maximum shutdown current of 1 µA and ±15 kV ESD protection. These are device specifications under the stated conditions, not guarantees for every circuit or bus configuration.
Do you need a bidirectional shifter for I²C?
I²C uses open-drain signaling: devices pull a line low and resistors pull it high. That means the translator must support the bus’s bidirectional, wired-low behavior; a fixed-direction buffer is not a drop-in replacement simply because its voltage range looks suitable. An auto-bidirectional part such as the LSF0102 is one architecture to evaluate, but its resistor/reference network and the complete bus conditions must follow the datasheet.
Rank #3
- Logic Level Converter: No soldering required! Our iic i2c 3.3v 5v logic level converter comes pre-soldered, simply plug it in and start enjoying seamless voltage conversion without the hassle.
- Multi-Channel Versatility: Each logic level shifter has the capability of converting 4 pins on the high side to 4 pins on the low side with two inputs and two outputs provided for each side.
- Universal Voltage Compatibility: Seamlessly interface your 5V and 3.3V devices with our iic i2c level shifter. It's the ultimate solution for ensuring your for Raspberry Pi, and other microcontrollers communicate flawlessly, no matter the voltage disparity.
- Enhanced Signal: The bi-directional logic level converter is a small device, which can safely steps down 5V signals to 3.3V and steps up 3.3V to 5V at the same time. Say goodbye to signal loss and voltage mismatch issues.
- Protect Your Components: Our logic level shifter 3.3v to 5v acts as a reliable buffer, shielding your devices from voltage mismatches and potential damage, providing a cost-effective safeguard.
For I²C, assess pull-up resistance and total bus capacitance together. Those determine edge behavior, so a translator’s headline data rate alone does not establish that the assembled bus will meet timing.
Check these limits before choosing a part
- Logic thresholds and output levels: Check VIH, VIL, VOH, and VOL in the exact datasheet against both connected devices. Voltage labels such as “1.8 V” and “5 V” are not sufficient.
- Absolute maximum ratings: Confirm that every pin remains within its permitted range in normal operation and during startup, shutdown, and fault conditions.
- Signal type and direction: Distinguish push-pull GPIO, UART, or SPI signals from open-drain buses such as I²C or MDIO. Determine whether direction is fixed, controlled by a pin, or automatically resolved by the translator.
- Speed and loading: Include bus capacitance, pull-up resistance, wiring, and edge-rate requirements rather than relying only on a headline data-rate figure.
- Channel count and package: Match the number of signals and required package to the design, including any need for three-state outputs.
- Control and power-off behavior: Check output-enable timing, shutdown or direction controls, sequencing requirements, and behavior when either connected voltage domain is unpowered.
When the second supply is still the right choice
A single-supply device is not automatically the simplest solution if the signal direction, logic thresholds, output drive, or power-off behavior do not match the application. A dual-supply transceiver can be preferable when both voltage domains need explicit control or when the interface requires bidirectional push-pull translation. Compare the actual electrical requirements and operating conditions rather than selecting solely by the number of supply pins.
Quick Recap
Best Value
- BI-DIRECTIONAL 4-CHANNEL VOLTAGE CONVERSION: Seamlessly bridge the gap between different logic levels. This module safely steps down 5V signals to 3.3V and steps up 3.3V signals to 5V simultaneously across all four channels, enabling true bi-directional communication on the same data line.
- WIDE DEVICE & PROTOCOL COMPATIBILITY: Engineered for versatility, this converter supports a broad range of logic levels including 5V, 3.3V, 2.8V, and 1.8V. It is ideal for interfacing devices using common protocols such as I2C, IIC, UART (tested up to 115200 baud), and SPI without signal degradation.
- ESSENTIAL FOR MCU & HOBBY PROJECTS: A must-have for any electronics enthusiast's toolkit. Reliably connect 3.3V microcontrollers like an ESP32 or a Raspberry Pi to 5V sensors and peripherals, or interface 5V AVR boards with 3.3V modules, protecting your components from voltage mismatches.
- EASY SETUP & GREAT VALUE PACK: Simply connect your high voltage source to the 'HV' pin, low voltage to 'LV', and a common ground to 'GND'. This value pack includes 10 converter modules and 20 unsoldered 6-pin male headers, providing ample supply for multiple projects and prototypes (soldering required).
- ROBUST MOSFET-BASED DESIGN: Each channel is equipped with a BSS138 MOSFET to ensure stable and reliable signal shifting for clean communication between your devices. We provide comprehensive after-sales support: complete digital documentation including user guides and technical references is available through our store customer service, and our support team is ready to assist with installation, programming, and troubleshooting to help you get started quickly.
Rank #4
- The bi-directional logic level converter is a small device, which can safely steps down 5V signals to 3.3V and steps up 3.3V to 5V at the same time.
- Each logic level converter has the capability of converting 4 pins on the high side to 4 pins on the low side with two inputs and two outputs provided for each side.
- it can bidirectionally transfer with 4 channels between high logic voltage and low logic voltage,it can works with 2.8V and 1.8V devices,
- Small size:1.3¡Á 1.5cm/ 0.51¡Á 0.59in.
- Compatible with breadboard, can be directly use in breadboard
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