12V 5 Amp Fixed Voltage Regulator IC 78H12A Datasheet

The post explains the technical specifications, datasheet, and application notes of the IC 78H12A which is a voltage regulator IC capable of providing a fixed regulated 12V output at maximum 5 amp current.

5 Amp Regulator Specifications

We are familiar with the popular 78XX ICs such as the 7812 IC which can produce 12V fixed voltage at its output with input supplies anywhere from 15V to 24V.

However the above device is capable of handling at the most 1 Amp of current which may be not sufficient for many standard applications.

For circuit applications which require currents as high as 5 amps, a higher rated alternative may be selected in the form of the IC 78H12A which is quite similar to its younger brother 7812 but is capable of handling up to 5 amps of current.

The main technical specifications or datasheet of this IC 78H12A may be studied with the following explanation:

The 78H12A is a three terminal  linear, positive fixed voltage regulator IC rated for continuously delivering around 5 amps of current with typical fixed 12 volts at its output.

The IC is internally fully protected a against short circuits or over loads at its output which makes it highly rugged and versatile.

In an event of a short circuit or over load across its output terminals, the device instantly shuts down the supply of power across its output leads, thus inhibiting any possibility of electrical hazards. The situation also protects the IC from getting damaged.

The above feature ensures safe operations of the connected electronics and also avoids the inclusion of external safety circuits reducing the cost and the component count of the over all configuration.

The device is available in a hermetically sealed TO-3 metal package, and facilitates easy fitting of an heatsink for better efficiency and working of the device.

Main Technical Features of the IC

The main features of the IC may be summarized as follows:

  1. Output Voltage: 12V, fixed, regulated
  2. Output Current: Maximum 5 Amps
  3. Protections: In-built short circuit and over load protected.
  4. Power Dissipation: 12 x 5 = 50 to 60 Amp Approximately
  5. Package: TO-3 metal body

Pin Outs of IC 78H12A

The figure below shows the pinout details of the IC 78H12A, if the device is held with the pins toward us and with the larger plain section of the area upwards, the right pin is the input, the left pin is the output while the body becomes the ground of the IC.

Application Notes

The IC 78H12A is fundamentally suited for all electronic circuit application where a fixed 12V is imperative and with requirements upto 5 amp, example for driving 12V DC motors, for driving high watt white LeDs for flood lighting, and also for charging lead acid batteries (with some modifications).

The following diagrams illustrate a couple of main applications which may be implemented with this versatile 12V 5 amp fixed voltage regulator IC.

12V 50 AH Battery Charger Circuit

30 watt LED Driver Circuit

48 thoughts on “12V 5 Amp Fixed Voltage Regulator IC 78H12A Datasheet

  1. Have questions? Please feel free to post them through comments! Comments will be moderated and solved ASAP.
  2. Hi…pls I need a circuit diagram (digital) than can display the batterry level of my inverter….pls really appreciate if u can help me do dat as soon as possible….

  3. Hi Swagatam,

    I am having 50 watt solar panel and 12 volts 15 watt DC table fan. I want to run DC fan with solar panel in day time.

    Can I use this IC 78H12A to regulate 12 volts output from solar panel and run all the day?
    why I am asking is my solar wattage is more (50watt) then the table fan (15watt). Is there any damage to table fan with higher wattage solar panel?


  4. hello sir,
    i wanted to make a 24 volt, 5ampere dc to 12 volt 5 ampere dc converter for heavy duty industrial vehicle as my project. so can u help me by giving circuit expalinaton and name of required components, please sir……..
    my name is subodh singh, live in kolkata.

  5. hello sir, my self subodh singh , live in kolkata, sir i m making a 24 volt, 5 ampere dc to 12 volt ,5 ampere dc converter. so i wanted to know is ic78h12 is suitable for this project. and can u help me by explaining the required circuit and also name the required components… please

  6. hello sir, my self subodh singh , live in kolkata, sir i m making a 24 volt, 20 ampere dc to 24 volt ,5 ampere dc converter. so i wanted to know which ic is suitable for this project. and can u help me by explaining the required circuit and also name the required components… please

  7. Sir can i use the 6a10diode as rectifier and also can i use this circuit to charge my 12v 36amp battery.the four 1n4007 will increase the voltage to 14v right?

  8. Hey Can I get his IC online in India? I checked local store but they don't have. Even when I search this on Google I am not able to find any Datasheet. Why so?

    Thanks in advance

  9. HI Swagatham, Can i use a LED panel of 24 Numbers of LED's of each 1 Watt in this 30 watt LED Driver Circuit???

    • yes you can, but if the LEDs are rated at 3.3V then the ideal way should be to make series of 4 LEDs in one string, and then connect 6 such strings in parallel and use with the above SMPS driver.

  10. Hello sir,
    My 3 wheel head lamp have 1w x 6 leds. Using PT 4115. It dmaged by maginto current. So I want 12v about 5 amp dc circuit. How I modififate above circuit for my requirement.

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