Power chip

This combo IC will integrate the power factor correction (PFC) and quasi-resonant flyback functions required to implement a compact, energy-efficient switch-mode power supply for adapter applications. The PFC stage exhibits near unity power factor when operating in critical conduction mode (CrM) with maximum frequency clamp. This circuit combines all the necessary functions needed to build a robust and compact PFC stage while minimizing the number of external components. The quasi-resonant current mode flyback stage has a proprietary valley lockout circuit that ensures stable valley switching. The system operates down to the 4th valley and switches to frequency foldback mode for minimum frequency clamping beyond the 4th valley, eliminating noise. Skip mode operation enables excellent energy efficiency at light loads with very low standby power consumption.

UC3842B, UC3843B series are high performance fixed frequency current mode controllers. These devices are specifically designed for off-line and DC-DC converter applications, providing designers with a cost-effective solution with minimal external components. These ICs feature a trimmed oscillator for precise duty cycle control, a temperature compensated reference, a high gain error amplifier, a current sense comparator, and a high current totem pole output suitable for driving power MOSFETs. Additionally, protection features are included, including input and reference undervoltage lockouts each with hysteresis, cycle-by-cycle current limit, programmable output dead time, and a latch for single-pulse metering. These devices are available in 8-pin dual inline plug-in and surface mount (SO-8) plastic encapsulation and 14-pin plastic surface mount (SO-14) encapsulation. The SO-14 encapsulation has separate power and ground pins for the totem pole output stage. The UCX842B has a UVLO threshold of 16 V (on) and 10 V (off), making it ideal for offline converters. The UCX843B is designed for low-voltage applications with UVLO thresholds of 8.5 V (on) and 7.6 V (off).

High Power Factor Pre-Regulator 8-SOIC 0 to 70

BiCMOS Power Factor Pre-Regulator 16-TSSOP -40 to 85