LM 7912 Negative Voltage Regulator To-252

If your board needs a steady −12V rail and your board print shows a small surface-mount 7912 in a TO-252 pack, this LM7912 negative voltage regulator is the part to order. It turns a higher negative input into a fixed −12V output for the negative side of a dual supply. It does not fit you if your board needs a positive voltage, a different negative voltage, or a through-hole part. Check the checks below before you order, so the sign, the voltage, the pins, and the heat plan all match your board.

This is an original, high-quality part.

What it does

Many analog boards need two supply rails: +12V and −12V. The positive side is easy to picture. The negative side needs a part that works below ground, and that is what this 7912 voltage regulator does. You feed it a negative input, and it holds the output at −12V even when the input or the load shifts a bit. It is a three-terminal part: Input, Ground, Output. In the standard test circuit it uses a 0.33 µF capacitor on the input and a 0.1 µF capacitor on the output.

This is a TO-252 surface-mount part. You solder it flat on the board, with its tab soldered down for heat. It is a small pack, so its heat limit matters: the total dissipation limit in this pack is 1.25W at 25 °C junction temperature. A big gap between input and output volts, times a heavy load current, makes heat fast. Work out your own heat before you order.

Who it fits

This part fits you if you repair or build dual-supply boards, audio boards, op-amp boards or sensor boards that need a −12V rail, and your board print shows a TO-252 7912 SMD part. It also fits if you are replacing a burnt surface-mount 7912 and your old part sat in the same TO-252 spot.

It does not fit you if your board needs +12V (that is a positive regulator, a different part), if it needs −5V or −15V, or if your board only has holes for a through-hole part. A 7912 SMD part will not drop into a through-hole footprint, and a −12V part will never give you +12V.

Checks before you order

• Sign and voltage: your board must need −12V, not +12V. The minus sign is the whole job here.
• LM7912 pinout: Pin 1 Ground, Pin 2 Input, Pin 3 Output, as shown in the official datasheet figure for this regulator family. This pin order is NOT the same as the positive 7812 family, so never copy a 7812 layout for a 7912.
• Package: TO-252 surface-mount, soldered flat on the board. If your board has through-holes for a TO-220 part, this pack will not fit without board work.
• Input range: the output voltage is tested over −14.5V to −27V input, and line regulation is tested over −14.5V to −30V. The absolute input maximum is −35V. Stay inside the tested range for steady work.
• Current and heat: the current limit is 1.5A, but the 1.25W pack limit bites first in most real jobs. Heat in watts is roughly (input volts minus 12V, in size) times load amps. A −24V input at 0.2A already makes about 2.4W, which is past this pack’s limit without strong board cooling. If your job runs hot, plan the cooling or pick a bigger pack.
• Capacitors: keep the input and output capacitors close to the part, as the standard circuit shows.

LM7912 Specifications

All figures below come from the TO-252 document for this part. No figure here was guessed.

Output voltage, fixed	−12 V
Output voltage at 25 °C	−11.5 V to −12.5 V
Output voltage, −14.5 V to −27 V input, 5 mA to 1 A	−11.4 V to −12.6 V
Maximum output current	1.5 A
Total dissipation, TO-252, 25 °C junction	1.25 W
Input voltage, absolute maximum	−35 V
Line regulation, −14.5 V to −30 V input	5 mV typical, 80 mV max
Load regulation, 5 mA to 1.5 A	15 mV typical, 200 mV max
Quiescent current (25 °C)	2 mA typical, 3 mA max
Dropout voltage (1 A, 25 °C)	1.1 V
Peak current (25 °C)	2.1 A
Package	TO-252, surface-mount
Operating junction temperature	0 °C to 150 °C
Storage temperature	−65 °C to +150 °C

If this part is not available, use one of these instead

Read the warning under the part before you swap. A swap must match on voltage, sign, pins, and pack, not on voltage alone.

• LM 7912 Negative Voltage Regulator To-220 — practical substitute only, NOT a drop-in. It does the same −12V regulator job, but it comes in a through-hole TO-220 pack, not the TO-252 surface-mount pack on this page. It only works if your board is reworked or an adapter is used to fit it. Its tab can shed more heat than the small TO-252 body, but that does not help unless the pack fits your board.

Warning: never swap on voltage alone. Check the sign (−12V, not +12V), the pin order, the pack, and the heat plan first. If any one of those does not match, do not swap.

LM7912 Other names for the same part (good to know)

Shoppers and repair techs call this same part by a few names. 7912 is the short name: “79” marks the negative regulator family and “12” marks the 12V size. In short, it is a -12V regulator TO-252 part. L7912 is the series code for the same −12V regulator. 7912 SMD is plain language for this same part in a surface-mount pack. Do not mix this TO-252 part up with the through-hole version even though the number is the same — the same number in a different pack still needs different board work.

LM7912 Frequently Asked Questions

What voltage does LM7912 give out?

A fixed −12V. At room temperature the output sits between −11.5V and −12.5V.

What is the LM7912 pinout for the TO-252 pack?

Pin 1 Ground, Pin 2 Input, Pin 3 Output, as shown in the official datasheet figure for this regulator family. This order is not the same as the positive 7812 family, so do not copy a 7812 layout.

Can I use the TO-220 version instead of this TO-252 part?

Only with board work. The TO-220 version does the same −12V job, but it is a through-hole part with a tab, not a surface-mount TO-252 part. It will not drop into a TO-252 footprint.

How much current can it give?

Up to 1.5A, but the 1.25W pack limit bites first in most real jobs. Work out your heat: (input volts minus 12V, in size) times load amps. If that number is past 1.25W, you need stronger board cooling or a bigger pack.

What input voltage does it need?

The output is tested over −14.5V to −27V input, and the absolute input maximum is −35V. Stay inside the tested range for steady work.

What is the price of this part?

Check the live price on the website. The price shown on the product page is the current one.

More parts in this group: ICs.

LM7912 Uses

You can view and download the datasheet for this part from the Datasheet button on this page.

This part is used in dual power supplies, audio electronics, industrial systems, and telecommunication equipment.