Details

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BUY UC2844N https://www.utsource.net/itm/p/12607862.html

Parameter	Symbol	Min	Typical	Max	Unit
Supply Voltage	Vcc	15	-	40	V
Start-Up Current	Icc(su)	1	-	3	mA
Operating Current	Icc(op)	3	-	7	mA
Error Amplifier Input Offset	Vos	-10	0	10	mV
Error Amplifier Gain	Aea	100	-	150	V/mV
Reference Voltage	Vref	4.9	5.0	5.1	V
Soft-Start Capacitance	Css	-	-	-	pF
Maximum Duty Cycle	Dmax	-	90	-	%
Switching Frequency	fsw	-	100	-	kHz
Under-Voltage Lockout	UVLO	10	-	15	V
Over-Voltage Protection	OVP	30	-	35	V
Thermal Shutdown Temperature	Tsd	150	-	160	掳C

Instructions for Using UC2844N

1. Power Supply:

   • Connect the supply voltage (Vcc) between 15V and 40V to the Vcc pin.
   • Ensure the start-up current (Icc(su)) is within 1 to 3 mA and the operating current (Icc(op)) is within 3 to 7 mA.

2. Error Amplifier:

   • The error amplifier input offset (Vos) should be within 卤10 mV.
   • The error amplifier gain (Aea) should be between 100 and 150 V/mV.

3. Reference Voltage:

   • The reference voltage (Vref) is typically 5.0V with a tolerance of 卤0.1V.

4. Soft-Start:

   • Use a capacitor (Css) on the soft-start pin to control the startup time. The value of this capacitor can be adjusted based on the desired startup duration.

5. Duty Cycle:

   • The maximum duty cycle (Dmax) is 90%. Ensure the design does not exceed this limit to avoid potential issues.

6. Switching Frequency:

   • The typical switching frequency (fsw) is 100 kHz. Adjust the external components to set the desired frequency.

7. Under-Voltage Lockout (UVLO):

   • The IC will shut down if the supply voltage drops below 10V and will restart when it rises above 15V.

8. Over-Voltage Protection (OVP):

   • The IC provides over-voltage protection and will shut down if the output voltage exceeds 30V to 35V.

9. Thermal Shutdown:

   • The IC will shut down if the temperature exceeds 150掳C and will restart once it cools down below 160掳C.

10. Layout Considerations:

    • Keep the layout compact and use short traces for high-frequency signals to minimize noise.
    • Place decoupling capacitors close to the Vcc pin to ensure stable operation.

11. Testing and Debugging:

    • Monitor the supply voltage, output voltage, and temperature during testing to ensure the IC operates within its specified parameters.
    • Use an oscilloscope to verify the switching waveform and adjust the external components as needed.

By following these instructions, you can ensure the UC2844N operates efficiently and reliably in your power supply design.

(For reference only)