LM7912 Negative Regulators: Diagram, Pinout and Datasheet

LM7912 is a three-terminal negative 12 volts voltage regulator IC，used for regulating negative voltages. 

It consists of three pins and has a fixed output voltage of -12V. Most of the applications need both positive and negative voltages for their operation. 

The negative voltages should be stable otherwise they can damage the circuit or reduce the life of components used in the circuit. Therefore, negative voltage regulators sever this application purpose.  

Symbol

Footprint

3D Model

• Thermal, short circuit and safe area protection

• High ripple rejection

• Output current: 1.5A

• Peak output current:2.2A

• The output voltage tolerance is ± 4%.

• fixed output voltage:-12V

• Average output current: up to 1A

• Package: TO-220 only

• The input voltage should lie in between -27V to -14.5V

• Safe area protection is provided for output transistors.

• It has a high power supply rejection ratio and low noise.

• It has a low quiescent current which ensures good regulation.

• 12V Negative voltage regulator

Texas Instruments LM7912CT technical specifications, attributes, parameters and parts with similar specifications to Texas Instruments LM7912CT.

−5V

−12V and −15V 

LM7912 belongs to the family of Voltage regulators. The name “79” indicates negative and the term “12” indicates the voltage. So “7912” means that this IC will regulate a negative 12V for your projects. You can also check on 78 series for positive voltage regulators.

When you are designing an analog circuit, the circuit might need negative voltage either as a power source or as a reference voltage. In both cases LM7912 will be an ideal choice when you need a negative 12V. The output current of this IC is upto 1A, however with appropriate heat sink the datasheet says that a peak current of 2.2A can be achieved through this IC.

The LM7912 is a -12V Voltage regulator IC. Meaning it will provide a constant output voltage of -12V when the input voltage is between -14.5V to -27V. A very basic Voltage regulator circuit is shown below.

I have used a Battery to power the IC, but you can use any power source but notice that the supply voltage should be negative. Hence, I have interchanged the polarity of the battery. The Input and output capacitors C1 (10uF) and C2 (1uF) are used to filter noise from the input and the output voltage respectively. The negative output voltage is obtained from the Vo (3rd Pin) which is also read using a Multimeter. The value of the capacitors need not be the exact values, you can use the closest value you have got.

There are many other ways in which the IC can be used based on your application. The circuit diagram for those can be found at the datasheet given at the end of this page.

●Use as power or reference voltage for analog and digital circuits.

● Current Limiter for certain applications

● Dual regulated supply.

● This IC can design a current limiter in various applications.

● High-sensitivity light controllers

● It also has a protection circuit for output polarity-reversal.

● LM7912 has a dual supply.

● High stability 1A regulator.

● As a current source.

● Light Controller using silicon photocell.

● Dual trimmed supply.

Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globally.[6] It is one of the top 10 semiconductor companies worldwide based on sales volume.The company's focus is on developing analog chips and embedded processors, which account for more than 80% of its revenue.TI also produces TI digital light processing technology and education technology products including calculators, microcontrollers and multi-core processors. The company holds 45,000 patents worldwide as of 2016.

Download datasheets and manufacturer documentation for Texas Instruments LM7912CT.