Build with L78M05 — Datasheet Specs & AI Design Help

00 — Overview

What the L78M05 does

The L78M series are precision 500 mA positive regulators available in 5, 6, 8, 9, 10, 12, 15, and 24 V fixed output voltages. These devices operate with a 2% or 4% tolerance depending on the version and support extended temperature ranges. They feature internal current limiting, thermal shutdown, and safe area protection to ensure robust operation. The regulators deliver up to 0.5 A output current when adequate heat sinking is provided. Available in TO-220, TO-220FP, DPAK, and IPAK packages, they are useful for local on-card regulation to eliminate distribution problems. Although designed as fixed voltage regulators, they can also function with external components to obtain adjustable voltage and currents.

Next step

Start building with L78M05 → Every number above is cited straight from the datasheet — ask what they mean for your design, and the assistant answers from the same source documents.

01 — Key specifications

Datasheet parameters

Datasheet parameters for L78M05
Parameter	Min	Typ	Max	Conditions	Source
quiescent current	—	—	6 mA	id	ST datasheet, p. 7 — Table 3. Electrical characteristics of L78M05C
output voltage	4.9 V	5 V	5.1 V	TJ = 25 °C; vo; Electrical characteristics of L78M05A	ST datasheet, p. 8 — Table 4. Electrical characteristics of L78M05A
output current	—	500 mA	—		ST datasheet, p. 1
supply voltage range	7 V	—	20 V		ST datasheet, p. 7 — Table 3. Electrical characteristics of L78M05C
operating temperature (abs max)	-40 °C	—	125 °C		ST datasheet, p. 5 — Table 1. Absolute maximum ratings
psrr	62 dB	—	—	VI = 8 to 18 V, f = 120 Hz, IO = 300 mA, TJ = 25 °C; Electrical characteristics of L78M05A	ST datasheet, p. 8 — Table 4. Electrical characteristics of L78M05A
dropout voltage	—	2 V	—	T_J = 25 \text{ °C}; v	ST datasheet, p. 14
output noise voltage	—	40 µV	—	B = 10 Hz to 100 kHz, TJ = 25 °C; en; Electrical characteristics of L78M05A	ST datasheet, p. 8 — Table 4. Electrical characteristics of L78M05A
output count	—	1	—		ST datasheet, p. 1

02 — Alternatives

Closest matches to L78M05

AZ1117-5.0 3.8× higher output noise voltage, 2.0× lower dropout voltage, 2.0× higher output current

L78L05AB 5.0× lower output current, 1.3× lower psrr, 1.2× lower dropout voltage

L78M05ABDT 2.6× higher supply voltage range, similar dropout voltage, similar operating temperature

AZ1117C-3.3 2.0× higher output current, 1.7× lower dropout voltage, 1.5× lower output voltage

LM7805 2.0× higher output current, 1.5× higher operating temperature, 1.3× higher quiescent current

AP2127-3.3 3.2× lower supply voltage range, 1.9× lower operating temperature, 1.5× lower output voltage

LD1117-3.3 4.2× lower output voltage, 2.5× higher output noise voltage, 2.0× lower dropout voltage

78M05 2.6× higher supply voltage range, 2.0× higher output current, 1.2× higher operating temperature

03 — FAQ

Frequently asked questions

What is the dropout voltage of the L78M05ABV at T_J = 25 °C?

The dropout voltage is 2 V at T_J = 25 °C.

What is the maximum operating temperature?

The maximum operating temperature is 125 °C.

What is the output count of the L78M05ABV?

The output count is 1.

What is the output current of the L78M05ABV?

The output current is 500 mA.

What is the output noise voltage of the L78M05ABV?

The output noise voltage is 40 µV at B = 10 Hz to 100 kHz and TJ = 25 °C.

What is the output voltage of the L78M05ABV at TJ = 25 °C?

The output voltage is 5 V.

What is the power supply rejection ratio (PSRR) of the L78M05ABV when VI = 8 to 18 V, f = 120 Hz, IO = 300 mA, and TJ = 25 °C?

The PSRR is 62 dB.

What is the quiescent current (id) for the L78M05ABV?

The quiescent current (id) is 6 mA.

What is the supply voltage range for the L78M05ABV?

The supply voltage range is 20 V.