Instructions for Use

1. Input Voltage:

   • Ensure the input voltage is within the range of 11.5V to 35V. The minimum input voltage must be at least 2V higher than the output voltage (9V) to ensure proper regulation.

2. Output Voltage:

   • The LM7809 provides a fixed output voltage of 9V. No external components are required for setting the output voltage.

3. Output Current:

   • The maximum continuous output current is 1.5A. Ensure that the load does not exceed this limit to avoid overheating or damage.

4. Heat Dissipation:

   • The thermal resistance from the junction to the case is 5°C/W. For high current applications, use a heatsink to dissipate heat effectively. Calculate the power dissipation (Pd = (Vin - Vout) * Iout) and ensure the heatsink can handle the thermal load.

5. Capacitors:

   • Place a 0.33μF capacitor between the input and ground close to the regulator to stabilize the input voltage.
   • Place a 0.1μF capacitor between the output and ground to improve transient response and stability.

6. Mounting:

   • Mount the LM7809 in a TO-220 package with proper mechanical support. Ensure good thermal contact with the heatsink if used.

7. Operating and Storage Temperature:

   • The operating temperature range is -40°C to 125°C, and the storage temperature range is -65°C to 150°C. Ensure the device operates within these limits to maintain reliability.

8. Short-Circuit Protection:

   • The LM7809 has internal short-circuit protection. However, it is recommended to use an external fuse to protect against excessive current draw.

9. Ripple Rejection:

   • The regulator provides 60dB ripple rejection at 120Hz. Use appropriate filtering capacitors to reduce input ripple and noise.

10. Package Marking:

    • The part number LM7809CT indicates the TO-220 package and the manufacturer (Fairchild).

By following these guidelines, you can ensure reliable operation of the LM7809CT in your circuit.