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.
They feature a trimmed oscillator for precise frequency control, current mode operation up to 500kHz, 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 family of control ICs has different under-voltage lockout thresholds and maximum duty cycle ranges.
The UC3842B and UC3844B are ideally suited for off-line applications, while the UC3843B and UC3845B have different thresholds.
The ICs have various pin functions and electrical characteristics, and are available in different ordering numbers and packages.
The datasheet also includes block diagrams, pin connections, ordering numbers, absolute maximum ratings, and electrical characteristics.
Additionally, it provides open loop test circuits, timing resistor vs.
oscillator frequency graphs, output dead-time vs.
oscillator frequency graphs, and other performance graphs.