Details

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BUY UC3844NG4 https://www.utsource.net/itm/p/12596504.html

Parameter	Symbol	Min	Typ	Max	Unit
Supply Voltage	Vcc	8.0	16.5	30.0	V
Start-Up Current	Icc(start)	-	1.0	-	mA
Operating Current	Icc(oper)	-	3.5	-	mA
Oscillator Frequency	fosc	1.0	500.0	500.0	kHz
Error Amplifier Gain	Aea	-	70.0	-	dB
Error Amplifier Bandwidth	f3db	-	12.0	-	kHz
Soft-Start Capacitance	CSS	-	-	-	pF
Maximum Duty Cycle	Dmax	-	94.0	-	%
Under-Voltage Lockout	UVLO	8.0	-	-	V
Over-Voltage Protection	OVP	-	-	36.0	V
Thermal Shutdown Threshold	TSD	-	160.0	-	°C

Instructions for Using UC3844NG4

1. Supply Voltage (Vcc):

   • Ensure the supply voltage is within the range of 8.0V to 30.0V. The typical operating current is 3.5mA.

2. Start-Up and Operating Current:

   • The start-up current is typically 1.0mA, and the operating current is typically 3.5mA.

3. Oscillator Frequency (fosc):

   • Set the oscillator frequency using an external resistor and capacitor. The typical range is from 1.0kHz to 500.0kHz.

4. Error Amplifier:

   • The error amplifier has a gain of 70dB and a bandwidth of 12kHz. Use external components to set the desired compensation network.

5. Soft-Start:

   • Implement soft-start by connecting a capacitor to the soft-start pin (CSS). The value of this capacitor determines the soft-start time.

6. Maximum Duty Cycle:

   • The maximum duty cycle is 94%. Ensure that the control loop does not exceed this limit to avoid instability.

7. Under-Voltage Lockout (UVLO):

   • The device will shut down if the supply voltage drops below 8.0V. This feature protects the IC from low-voltage conditions.

8. Over-Voltage Protection (OVP):

   • The device has built-in over-voltage protection, which triggers at 36.0V. This feature helps protect the IC and connected components from over-voltage conditions.

9. Thermal Shutdown:

   • The device will shut down if the internal temperature exceeds 160°C. This feature provides thermal protection to prevent damage due to overheating.

10. Layout Considerations:

    • Use short, wide traces for power and ground connections to minimize parasitic inductance.
    • Place decoupling capacitors close to the Vcc and GND pins to ensure stable operation.

11. Application Notes:

    • Refer to the datasheet and application notes for detailed information on specific applications and circuit design guidelines.

(For reference only)