Pulse Width Modulation (PWM) Controller IC; Output Current:500mA; Frequency:450kHz; Power Dissipation, Pd:1W; Supply Voltage Range:8V to 40V; Digital IC Case Style:LCC; No. of Pins:20; Operating Temperature Range:-40°C to +85°C
The UC1846/7 family of control ICs provides all of the necessary features to implement fixed frequency, current mode control schemes while maintaining a minimum external parts count. The superior performance of this technique can be measured in improved line regulation, enhanced load response characteristics, and a simpler, easier-to-design control loop. Topological advantages include inherent pulse-by-pulse current limiting capability, automatic symmetry correction for push-pull converters, and the ability to parallel "power modules" while maintaining equal current sharing. Protection circuitry includes built-in under-voltage lockout and programmable current limit in addition to soft start capability. A shut-down function is also available which can initiate either a complete shutdown with automatic restart or latch the supply off. Other features include fully latched operation, double pulse suppression, deadline adjust capability, and a 1% trimmed bandgap reference. The UC1846 features low outputs in the OFF state, while the UC1847 features high outputs in the OFF state.