the aip3842/aip3843/aip3844/aip3845 are fixed frequency current-mode pwm controller. they are specially designed for off-line and dc-to-dc converter applications with minimum external components. these integrated circuits feature a trimmed oscillator for precise duty cycle control, a temperature compensated reference, high gain error amplifier. current sensing comparator, and a high current totempole output ideally suited for driving a power mosfet. protection circuit includes built in under-voltage lockout and current limiting. the aip3842 and aip3844 have uvlo thresholds of 16v (on) and 10v (off). the aip3843 and aip3845 are 8.8v (on) and 7.6v (off) .the aip3842 and aip3843 can operate within 100% duty cycle. the aip3844 and aip3845 can operate with 50% duty cycle.