The UC2843A control IC is a pin-for-pin compatible improved version of the UC2843. Providing the necessary features to control current mode switched mode power supplies, this device has the following improved features. Start up current is specified to be less than 0.5 mA. Oscillator discharge is trimmed to 8.3 mA. During undervoltage lockout, the output stage can sink at least 10 mA at less than 1.2 V for VCC over 5 V.