The UC2842B/3B/4B/5B and UC3842B/3B/4B/5B are high-performance current mode PWM controllers designed for off-line or DC to DC fixed frequency current mode control schemes with minimal external parts.
They feature a trimmed oscillator for precise frequency control, with an oscillator frequency guaranteed at 250kHz and current mode operation up to 500kHz.
The controllers also include automatic feed forward compensation, latching PWM for cycle-by-cycle current limiting, internally trimmed reference with undervoltage lockout, and a high current totem pole output.
The differences between the members of this family are the under-voltage lockout thresholds and maximum duty cycle ranges.
The controllers have various electrical characteristics and pin functions, and are available in different ordering numbers and package types.
The controllers also have absolute maximum ratings and thermal data.
The summary also includes block diagrams, pin connections, and electrical characteristics for the controllers.
Additionally, the summary includes open loop test circuits, timing resistor vs.
oscillator frequency graphs, output dead-time vs.
oscillator frequency graphs, and other graphs related to the controllers' performance.