L7805CV Voltage Regulator: Pinout, Equivalent, Circuits

The L7805CV is a popular 5 V voltage regulator used to power logic circuits, sensors, and microcontrollers. This guide covers its pinout, compatible replacements, and a simple circuit with clear explanations.

L7805CV Key Features

· Output Voltage: Fixed 5 V ±2%
· Max Output Current: 1.5 A (requires heatsink)
· Input Voltage Range: Recommended 7 V to 35 V
· Dropout Voltage: Around 2 V at full load
· Protections: Built-in thermal shutdown, short-circuit, current limiting, SOA protection
· Package: TO-220 (also available as TO-220FP, DPAK, D²PAK)
· Operating Temp.: –40 °C to +125 °C

L7805CV Pinout

The L7805CV comes in the standard TO‑220 package with three pins:


Note:
· Input voltage should be at least 7 V to maintain a stable 5 V output.
· Pin 2 is ground—connect it properly to avoid instability.
· Place a 0.33 µF capacitor at the input and 0.1–1 µF at the output, close to the pins.
· The metal tab is ground—insulate it if mounted to a metal surface.
· If current exceeds 500 mA, use a heatsink to prevent overheating.

L7805CV Typical Application Circuit

This is a simple 5 V power supply using the L7805CV and two capacitors.

Circuit Analysis:
· C1 (0.22 µF) at the input suppresses high-frequency noise.
· C2 (0.1–1 µF) at the output improves transient response and stability.
· Vin should be ≥ 7 V to ensure stable 5 V output.
· Use a heatsink if output current exceeds 500 mA.

· Add a diode (e.g., 1N4007) from Vout to Vin to prevent reverse current when using large output capacitors.

L7805CV Equivalent

Replacement Notes:
· For direct replacement, LM7805CT and LM340T‑5.0 are fully compatible.
· LM1084‑5.0 provides higher output current and better regulation but may require layout and thermal adjustments.

Conclusion

The L7805CV is one of those parts that just works. It’s simple, reliable, and gives you a clean 5 V with barely any extra components. Need more current or tighter accuracy? Just swap in something like the LM1084 or LM340T. It’s a solid pick whether you’re just testing a circuit or building something permanent.