SLUSDD4B April 2019 – December 2020 UC1843B-SP
The UC1843B-SP uses fixed frequency, peak current mode control. An internal oscillator initiates the turnon of the driver to high-side power switch. The external power switch current is sensed through an external resistor and is compared via internal comparator. The voltage generated at the COMP pin is stepped down via internal resistors, as shown in Section 7.2. When the sensed current reaches the stepped down COMP voltage, the high-side power switch is turned off.