Details

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BUY UC3903N https://www.utsource.net/itm/p/11711464.html
IC SUPPLY/LINE MONITOR 18-DIP

Parameter	Symbol	Conditions	Min	Typical	Max	Unit
Supply Voltage	Vcc	Operating	4.5	-	28	V
Output Current	Iout	Continuous	-	1.5	2.0	A
Shutdown Current	Ishutdown	Vcc = 5V, Shutdown mode	0.1	-	1.0	μA
Thermal Shutdown Temperature	Tshut	-	160	-	-	°C
Overcurrent Protection	Iocp	-	2.2	-	2.8	A
Quiescent Current	Iq	Vcc = 5V, No load	2.0	-	4.0	mA
Dropout Voltage	Vdo	Iout = 1.0A, Vcc = 5V	0.4	-	1.0	V
Line Regulation	ΔVout/ΔVin	Iout = 1.0A, Vcc = 5V to 28V	-	0.01	-	%
Load Regulation	ΔVout/ΔIout	Vin = 5V, Iout = 0 to 1.5A	-	0.1	-	%
Ripple Rejection	AVRR	10Hz to 100kHz, Vcc = 5V	-	70	-	dB

Instructions for UC3903N

1. Power Supply Connection:

   • Connect the positive terminal of the power supply to the Vcc pin.
   • Connect the negative terminal (GND) to the ground pin.

2. Output Configuration:

   • Connect the load to the output pin (OUT).
   • Ensure the load current does not exceed the maximum output current rating.

3. Thermal Management:

   • Ensure adequate heat dissipation to prevent thermal shutdown.
   • Use a heatsink if necessary, especially for high current applications.

4. Shutdown Mode:

   • To activate the shutdown mode, connect the SHDN pin to GND.
   • The shutdown current is very low, allowing for minimal power consumption when the device is not in use.

5. Overcurrent Protection:

   • The device automatically limits the output current to prevent damage.
   • If the overcurrent condition persists, the device will shut down to protect itself.

6. Line and Load Regulation:

   • The device maintains a stable output voltage under varying input voltages and load conditions.
   • For optimal performance, ensure the input voltage and load current remain within the specified ranges.

7. Ripple Rejection:

   • The device has good ripple rejection, which helps in maintaining a clean output voltage even with noisy input sources.

8. Capacitor Selection:

   • Use appropriate input and output capacitors to stabilize the power supply and reduce ripple.
   • Typical values are 10μF for input and 10μF for output, but these can vary based on specific application requirements.

9. PCB Layout:

   • Keep the power and ground traces as short and wide as possible to minimize voltage drops and improve thermal performance.
   • Place the input and output capacitors close to the respective pins to reduce parasitic inductance.

10. Storage and Handling:

    • Store the device in a dry, cool place to prevent moisture damage.
    • Handle the device with care to avoid static discharge, which can damage the internal circuits.

By following these instructions, you can ensure reliable operation and optimal performance of the UC3903N.

(For reference only)