The UC3844B and UC3845B series are high performance fixed frequency current mode controllers designed for off-line and dc-dc converter applications.
They offer a cost-effective solution with minimal external components.
These integrated circuits feature an oscillator, a temperature compensated reference, high gain error amplifier, current sensing comparator, and a high current totem pole output ideally suited for driving a power MOSFET.
They also include protective features such as input and reference undervoltage lockouts, cycle-by-cycle current limiting, and a latch for single pulse metering.
The devices are available in 8-pin dual-in-line and surface mount plastic packages, as well as 14-pin plastic surface mount packages.
The UC3844B has UVLO thresholds of 16 V (on) and 10 V (off), while the UC3845B has UVLO thresholds of 8.5 V (on) and 7.6 V (off).
The devices also have features such as trimmed oscillator for precise frequency control, automatic feed forward compensation, and latching PWM for cycle-by-cycle current limiting.
They are available in Pb-Free packages and have various ordering options for different temperature ranges and package types.
The maximum ratings, electrical characteristics, and ordering information for the devices are also provided in the document.