Instructions for Use:

1. Input Voltage (VI):

   • Ensure the input voltage is within the specified range (4.5V to 20V) to avoid damage to the device.

2. Output Voltage (VO):

   • The UA78S40PC provides a fixed output voltage of 4.0V. No external components are required for this fixed voltage.

3. Output Current (IO):

   • The device can supply up to 1.5A continuously. For higher current requirements, consider using a heat sink or a more powerful regulator.

4. Line Regulation:

   • The output voltage will change by 0.04% per volt change in input voltage. This is typically not a concern for most applications but should be considered in precision circuits.

5. Load Regulation:

   • The output voltage will change by 1.0% to 1.5% when the load changes from no load to full load. This is within acceptable limits for most applications.

6. Dropout Voltage (VD):

   • The minimum input-to-output voltage difference required for regulation is 1.7V to 2.5V. Ensure that the input voltage is always at least this much higher than the output voltage.

7. Quiescent Current (IQ):

   • The device consumes 5mA to 10mA of current when regulating. This is relatively low and should not significantly affect the overall power consumption of your system.

8. Thermal Shutdown (TSD):

   • The device will shut down if the temperature exceeds 160°C to 180°C to prevent damage. Use a heat sink if operating in high-temperature environments or under high load conditions.

9. Short-Circuit Current (ISC):

   • The device can handle short circuits up to 1.5A to 2.0A. However, prolonged short circuits can cause the device to overheat and trigger thermal shutdown.

10. Operating Temperature (TOPR):

    • The device can operate in ambient temperatures ranging from -40°C to 125°C. Ensure adequate cooling if operating near the upper limit.

11. Storage Temperature (TSTG):

    • Store the device in temperatures ranging from -65°C to 150°C to ensure long-term reliability.

Additional Notes:

• Capacitors:
  • It is recommended to use a 0.33μF capacitor on the input and a 0.1μF capacitor on the output to stabilize the regulator and filter out noise.
• Heat Sink:
  • For applications where the device will be operating near its maximum current or in high ambient temperatures, a heat sink may be necessary to dissipate excess heat and maintain reliable operation.