July - revised July Internally implemented circuits include a trimmed. Protection circuitry includes built undervoltage lockout. Absolute Maximum Ratings.
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This article covers only on the 8-Pin version of the IC. It is an output pin which outputs low impedance 1MHz single based in the difference between he set and current voltage. It is normally connected to the voltage feedback pin of the IC through resistor and capacitor. It is an input to the error amplifier that inside the IC.
The difference in voltage level is supplied to this pin. A shunt resistor is used to monitor the current through the circuit and the voltage across it is provided as a feedback to the current sense pin. The IC has an internal oscillator which can be set using an external Resistor and capacitor connected to this pin. This pin outputs the PWM signal based on the feedback provided and we can use this to switch the power electronic device.
While building Switch mode supplies with feedback there are two modes of control that is commonly used, one is voltage mode control where the output voltage will kept constant irrespective of the current CV mode and the other is current mode control where the output current will be constant C mode irrespective of the voltage. Although the IC performs a sophisticated job, using it in a circuit is fairly simple and can be done with minimum number if external components which make this IC to be a preferable choice among designers.
A sample application circuit of this IC is shown below. The IC has an under voltage protection, so care should be taken to make sure that it has an operating voltage between 7V to 8.
The output pin of the IC is connected to the gate driver circuit of the Power switch which is to be switched. The output pin can source upto 1A ad hence a current limiting resistor will be required.
A shunt resistor is used to monitor the change in current in the circuit and then this difference voltage across the shunt is provided to the feedback pin.
The Datasheet recommends a value of between pf to 4. Refer the datasheet at the end of the page to know more about this IC. Also check out the Layout diagram at the bottom of the datasheet for a quick start. A more detailed application circuit is shown below. Subscribe to stay updated with industry's latest Electronics components and news. How o use UC IC Although the IC performs a sophisticated job, using it in a circuit is fairly simple and can be done with minimum number if external components which make this IC to be a preferable choice among designers.
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