DD38LOSA 3.3V DC-DC / LDO Module

The DD38LOSA 3.3V DC-DC / LDO Module provides a reliable and efficient way to generate a clean 3.3V output from a wide input range of 8V to 40V. By combining a switching regulator with a linear regulator, it ensures reduced noise and ripple while delivering stable performance for sensitive applications. Capable of providing 700mA continuous current (up to 1A intermittent), this module features built-in short-circuit and thermal protection. Compact and breadboard-friendly, it is ideal for powering microcontrollers, sensors, and other low-voltage devices in projects requiring stable 3.3V power. Featured By RoboticsBD.

Product Images are shown for illustrative purposes only and may differ from the actual product.

RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD 

Features:

1. Input voltage range: 8–40V.

2. Regulated 3.3V output voltage.

3. Continuous current up to 700mA, 1A peak.

4. Combines DC-DC and LDO regulation for clean, stable output.

5. High efficiency: 60–70% overall.

6. Output ripple: 12–20mV under normal load.

7. Short-circuit and thermal protection.

8. Compact, TO-220 compatible pinout for easy integration.

9. Tested to run at 800mA extended load without issues.

10. Breadboard-friendly design with minimal wiring needs.

RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD 

Applications:

1. Powering 3.3V microcontrollers such as ESP32, ESP8266, STM32, or Arduino-compatible boards.

2. Supplying clean 3.3V power to sensors, communication modules, and ICs.

3. Use in embedded projects requiring stable low-voltage supply.

4. Industrial and IoT devices powered from higher voltage sources.

5. Prototyping on breadboards and experimental setups.

6. Educational projects involving regulated power supply design.

RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD 

Please allow 5% measuring deviation due to manual measurement.

RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD 

Documentation:

THEORY OF OPERATION:

The DC-DC input section can take a range of 8 to 40V on its input.

It uses the ME3116 switching regulator IC that operates at 550kHz and is configured to provide a fixed output voltage set to 6.3V.  Efficiency of this section is 85-90%.

The 6.3V is then feed to an LDO 1117A-5 linear regulator.  This regulator trims the 6.3V down to the final 3.3V output while also helping to filter the ripple and noise on the output of the DC-DC section.  Efficiency of this section is 71-78% giving an overall efficiency of 60-70% for the module.

The final output has a ripple of 12-20mV under most conditions.  It doesn’t remove it completely due to the tight circuit coupling between the DC-DC converter and linear sections on the small board.  It is still 2-10x better than what most DC-DC converters can provide when used alone.  Measurements were done with a 100uF bulk capacitor on the output.

Because the linear regulator is always dropping a minimal voltage amount, it can operate at its full 700mA current rating independent of the input voltage.

RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD 

Module Connections

There is a 3-pin right angle header for making connections.

1 x 3 Header

• I = Vin – Connects to 8 – 40V
• G = Ground
• O = 3.3V output

RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD 

OUR EVALUATION RESULTS:

These are handy modules that can help resolve some common problems related to trying to generate a fairly clean 3.3V from a relatively high input voltage without having to derate the output current based on the input voltage like when using a linear regulator alone.

We tested these over over the full range of 8 to 40V at 700mA load without any issues.  At full load the module does run quite warm as expected.

The modules can handle up to 1A for short periods of time and we have tested to 800mA for extended periods at 25C ambient.

One quirk we have seen in our testing is that if the load is more than 600mA without any bulk capacitance on its output, the output can go into a current limit or other shutdown mode when power is first applied.  We have only seen this when testing using electronic dummy loads.  Add even a 10uF capacitor on the output resolves this, so it is not expected to be an issue under normal circuit conditions.

One thing to be aware of whenever using any breadboard friendly power module is that while the module may be able to handle 700+mA, the typical breadboard jumper wires will have a fairly significant voltage loss passing that much current. When using with higher current loads you may need to double-up on the wires or use heavier gauge wires on the output voltage connections to minimize the voltage drop.

RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD 

Package Includes:

1 x DD38LOSA 3.3V DC-DC / LDO Module

RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD 

RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD RoboticsBD