Details
BUY UC3844 https://www.utsource.net/itm/p/12536147.html
Parameter | Symbol | Min | Typ | Max | Unit | Description |
---|---|---|---|---|---|---|
Supply Voltage | Vcc | 10.0 | 16.0 | 35.0 | V | Operating range of the supply voltage |
Start-Up Current | ISTART | - | 2.0 | - | mA | Current required to start the IC |
Operating Current | IOP | 2.5 | 3.5 | 4.5 | mA | Current required for normal operation |
Shutdown Current | ISD | 50 | 75 | 100 | μA | Current consumption in shutdown mode |
Oscillator Frequency | fOSC | 100 | 500 | 1000 | kHz | Range of the oscillator frequency |
Reference Voltage | VREF | 4.95 | 5.0 | 5.05 | V | Stable reference voltage output |
Error Amplifier Gain | AEA | 50 | 100 | 150 | V/μA | Gain of the error amplifier |
Compensation Pin Output Current | ICO | 0.1 | 0.5 | 1.0 | mA | Maximum current from the compensation pin |
PWM Comparator Input Voltage | VCOMP | 0.5 | 1.0 | 1.5 | V | Input voltage range for the PWM comparator |
PWM Output Duty Cycle | D | 0 | 50 | 100 | % | Range of the PWM output duty cycle |
Thermal Shutdown Temperature | TSD | 150 | 160 | 170 | °C | Temperature at which the IC shuts down to prevent damage |
Instructions for Using the UC3844
Supply Voltage (Vcc):
- Ensure the supply voltage is within the specified range (10V to 35V) to avoid damage or improper operation.
Start-Up Current (ISTART):
- The IC requires a minimum start-up current of 2mA. Ensure the power supply can provide this current.
Operating Current (IOP):
- The operating current is typically 3.5mA. Design the power supply to handle this current continuously.
Shutdown Current (ISD):
- In shutdown mode, the IC consumes approximately 75μA. This is useful for low-power applications.
Oscillator Frequency (fOSC):
- Set the oscillator frequency using an external resistor and capacitor. The typical range is 100kHz to 1000kHz.
Reference Voltage (VREF):
- The stable reference voltage is 5.0V ± 1%. Use this for precise voltage regulation.
Error Amplifier Gain (AEA):
- The error amplifier gain is typically 100 V/μA. Adjust the feedback network to achieve the desired regulation.
Compensation Pin Output Current (ICO):
- The maximum current from the compensation pin is 1.0mA. Use this for loop compensation to stabilize the control loop.
PWM Comparator Input Voltage (VCOMP):
- The PWM comparator input voltage should be within 0.5V to 1.5V. This voltage determines the PWM duty cycle.
PWM Output Duty Cycle (D):
- The PWM output duty cycle can range from 0% to 100%. Use the feedback and control circuitry to set the desired duty cycle.
Thermal Shutdown Temperature (TSD):
- The IC will shut down if the temperature exceeds 160°C to prevent thermal damage. Ensure proper heat dissipation.
Additional Notes:
- Always refer to the datasheet for detailed information and specific application notes.
- Proper PCB layout and component selection are crucial for reliable operation.
- Use appropriate decoupling capacitors near the Vcc pin to ensure stable operation.
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