Details

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BUY UC3845BD1R2 https://www.utsource.net/itm/p/11246512.html

Parameter	Description	Min	Typ	Max	Unit
Supply Voltage (Vcc)	Operating supply voltage range	10	-	40	V
Start-Up Current	Minimum current required for start-up	-	1.5	-	mA
Operating Current	Typical operating current	-	5	-	mA
Reference Voltage	Stable output reference voltage	4.95	5.0	5.05	V
Oscillator Frequency Range	Adjustable frequency range	10	-	500	kHz
Maximum Duty Cycle	Maximum achievable duty cycle	-	95	-	%
Error Amplifier Gain	Open-loop gain of the error amplifier	-	100	-	dB
Error Amplifier Bandwidth	Bandwidth of the error amplifier	-	10	-	kHz
Thermal Shutdown Temperature	Temperature at which thermal shutdown occurs	-	160	-	°C
Storage Temperature Range	Temperature range for storage	-40	-	125	°C
Operating Temperature Range	Temperature range for operation	-40	-	125	°C

Instructions for Using the UC3845BD1R2:

1. Supply Voltage (Vcc):

   • Ensure the supply voltage is within the range of 10V to 40V.
   • Use appropriate filtering and bypass capacitors to stabilize the supply voltage.

2. Start-Up Current:

   • The device requires a minimum of 1.5mA for start-up. Ensure that the power supply can provide this current.

3. Operating Current:

   • The typical operating current is 5mA. Design the power supply to handle this current.

4. Reference Voltage:

   • The stable output reference voltage is 5.0V with a tolerance of ±0.5%. Use this reference for feedback and control loops.

5. Oscillator Frequency Range:

   • Set the oscillator frequency using an external resistor and capacitor. The range is from 10kHz to 500kHz.

6. Maximum Duty Cycle:

   • The maximum duty cycle is 95%. Ensure that the design does not exceed this limit to avoid overdriving the output stage.

7. Error Amplifier Gain and Bandwidth:

   • The error amplifier has a gain of 100dB and a bandwidth of 10kHz. Use these parameters to design the feedback loop for stability and performance.

8. Thermal Shutdown:

   • The device will shut down if the temperature exceeds 160°C. Ensure proper heat dissipation and cooling to prevent thermal shutdown.

9. Storage and Operating Temperature:

   • Store the device between -40°C and 125°C.
   • Operate the device within the same temperature range to ensure reliable performance.

10. Layout Considerations:

    • Use short, wide traces for high-frequency signals and power lines.
    • Place bypass capacitors close to the IC to minimize noise and improve stability.

11. Protection Circuits:

    • Implement overvoltage, undervoltage, and overcurrent protection circuits to safeguard the device and the system.

12. Testing and Debugging:

    • Test the circuit under various conditions to ensure it meets the design specifications.
    • Use an oscilloscope to monitor key signals and identify any issues.

By following these instructions, you can effectively use the UC3845BD1R2 in your power supply or control circuit designs.

(For reference only)