PS-1A Adjustable miniature switch mode DC-DC Regulator
DC-DC converters or DC-DC regulators are used in almost any electronic project. PS-1A is an adjustable switch mode DC-DC converter that has the size and ease of use of linear regulators. PS-1A combines all the components required for a switch mode power supply to a compact 4 layer PCB. PS-1A is extremely efficient and can reach efficiencies over 95%. This is makes it highly suitable for battery powered applications. The overall package is similar in size and pin layout to the TO 220 package which is used by the 78XX series linear regulators such as 7805. PS-1A is in fact pin compatible with 78XX series linear regulators.
PS-1A accepts a wide input voltage range of 3V-17V. The output voltage range is 0.9V-6V with a maximum current output of 1A. The output voltage can be adjusted by turning a potentiometer. Since the output voltage is adjustable PS-1A can be used to provide power to many electronic devices including but not limited to.
- Arduino (5V)
- Teensy (3.3V)
- LEDs (1.8V-3V)
PS-1A is breadboard friendly making it easy to prototype with. PS-1A is a step down or buck converter. Therefor the maximum output voltage does not exceed the input voltage. For example if you use a 5V input voltage the maximum output voltage you can get is 5V. PS-1A uses a highly integrated switch mode DC-DC controller developed by Texas Instruments.
Easy to Use: PS-1A does not require any external components. Please connect it to the power source and the device as shown in the figure below. It can be plugged into a breadboard for prototyping.
Compact Size: At 10mmx15mm it is about the same size as 78xx series linear regulator ICs. Detailed dimensions are given in figure.
Efficiency: Being a switch mode regulator PS-1A is extremely efficient and can reach efficiencies over 95%.
Adjustable Output: The output voltage of PS-1A can be adjusted by turning a potentiometer. Please see the figure below.
PS-1A is pin compatible with 78xx series linear regulator ICs and can be used as a drop in replacement for them.
Being an efficient switch mode regulator PS-1A does not generate large amount of heat. However, the PCB of PS-1A has been carefully designed to dissipate the heat it generates. The rear side of PS-1A contains an exposed copper pad connected to the ground of PS-1A. This copper pad is also connected to the thermal pad of the controller IC of PS-1A by thermal vias. This design provides a low thermal resistance path to dissipate the heat generated by PS-1A.
PS-1A Thermal Handling
PS-1A inherits several safety features from its DC-DC regulators IC.
- Input Under Voltage Lockout : The controller of PS-1A monitors the input voltage level and stops switching its MOSFETS if the input voltage is lower than a threshold value.
- Output Current Limit and Short Circuit Protection: When a threshold output current limit is reached switching of MOSFETS is halted and the high side MOSFET is turned off.
- Thermal Protection: The controller of PS-1A monitors the device temperature and turns of the MOSFESTs when a threshold temperature is reached.
Using PS-1A as a Fixed Output DC-DC Regulator
The output voltage of PS-1A is adjusted by turning a potentiometer. Replacing the potentiometer by a fixed resistor would set the output voltage of PS-1A to a fixed value. The PCB of PS-1A contains a footprint to solder a surface mount fixed resistor instead of the potentiometer. This can be done by the user using commonly used soldering equipment. The equation for computing the resistor value required to obtain the desired output voltage is provided in the datasheet. Please contact Invinyx Electronics if you require PS-1A in a fixed output configuration and would like us to do it for you.
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