Multi-Output 3.3 / 5V Power Module

6-12VDC input and outputs both 3.3V and 5V

DESCRIPTION

This small Multi-Output 3.3 / 5V Power Module accepts 6-12VDC via a standard DC power jack or male header pins and outputs both 3.3V and 5V for powering breadboards or other small projects.

PACKAGE INCLUDES:

• Multi-Output 3.3 / 5V Power Module

KEY FEATURES OF MULTI-OUTPUT 3.3 / 5V POWER MODULE:

• Accepts 6-12V input via standard DC power jack or male header
• Output 1:  +3.3V at up to 800mA
• Output 2:  +5V at up to 800mA
• Output 3:  DC input is available as an output
• Power switch and power on LED Indicator

This module provides an inexpensive and convenient way to convert a 6-12V wall bug or battery pack into 5V and 3.3V to power a solderless breadboard setup or other small project. Being inexpensive, it does have some limitations but it works well as long as you stay within those limitations which are outline below. If you have a nice bench supply, this can be used to free-up your bench supply for other duties.

Note that there are a couple of versions of this module with slight layout differences such as swapping locations of 3.3V vs 5V headers, but functionality between them is the same.

Input Power

DC Power Jack:

Power can be input via a standard DC Power Jack.  Input power should be kept between 6-12VDC.

The regulators can technically handle up to 15V on their inputs, but the output current will be more limited with higher input voltages as detailed below and so 12V should be considered the upper limit. In general, running these off a 6-9V input will give you the best performance.  We have a 7.5V 1A AC Adapter that works great with these modules or for mobile use our 6 or 9V battery to DC Plug adapter works well.

DC-IN/OUT

These headers are directly connected to the DC power jack after the switch.  In some applications, it may be more convenient to jumper power over to the module using these pins rather than using the power jack.

Output Voltages

The output voltages are available on 3 sets of 2×3 headers with 3 power pins and 3 grounds available for each voltage.  The ground pins are all common on the board.

• 5V OUT = 5VDC Output
• 3V3 OUT = 3.3VDC Output
• DC-IN/OUT = If power is coming in on the DC jack, that voltage is available as an output on these pins.  You can also feed the module 6-12VDC on these pins rather than using a DC jack to bring in power.

Power Control:

Power is controlled with a push on / push off button. The button does not have much tactile feel, so you will need to rely upon the power LED to tell you if power is on or off to the breadboard.  The button will also stay depressed when ON.

OUR EVALUATION RESULTS:

For the price, these are handy little modules.

The output voltages are created using 2 AMS1117 low drop-out linear regulators. The two regulators are run in parallel off the DC input power so they can both be loaded up to their maximum capability.  Note that 800mA is the maximum possible chip current draw, but the practical maximum output is heavily dependent on the input voltage powering the module.

If you want to push the power boundaries of the module and know where those limits are, it is easiest to think about the power dissipation of the regulators.  The max power the regulators can dissipate is 1.2W which is internally regulated.  If the chip is pushing up against that thermal spec, it will start to throttle back on the output voltage / current.

As linear regulators, the amount of voltage that must be dropped from the input to the output must be dissipated as heat within the package. Keeping the input voltage on the low side, such as using our 7.5V wall adapter, reduces the amount of voltage that must be dropped and therefor allows the regulators to output higher current than say if they are operated off of 12V.

As an example, with a 7.5V input the maximum current on the 5V output can be calculated using ohms law for power P=IE which can be changed to I=P/E to solve for current.

If max power of the device is 1.2W and the voltage drop from 7.5V to 5V is 2.5V, the formula is:  I = 1.2W / 2.5V = 500mA.  In this case, 500mA will be the maximum current that can be pulled.

Since the 3.3V regulator needs to drop more voltage with the same input power, the maximum output will always be lower than the 5V regulator and in this case will be around I = 1.2W / 4.2 =  280mA.

If the input is operated at the minimum 6V, the 5V regulator can reach the full 800mA output and the 3.3V can output about 600mA.

If you only care about 3.3V,  you can power the module off 5V and pull the full 800mA off the 3.3V regulator.  In this case, the 5V regulator output will not be usable, but the 5V would be available on the DC-IN pins.

The good news is that if you guess wrong on the current draw, the regulators have thermal protection built-in so if you draw too much power, they will safely shutdown before damage can occur. If that happens, you need to look for ways to reduce your power draw or perhaps use a lower voltage power source to power the module from to reduce the power dissipation. The regulators are also output short circuit protected, so accidentally shorting the outputs to ground won’t cause permanent damage.

BEFORE THEY ARE SHIPPED, THESE MODULES ARE:

• Sample inspected and tested per incoming shipment

Notes: 

1. Under high current loads, the components can get fairly hot to the touch.

TECHNICAL SPECIFICATIONS