Compact primary-side regulation PWM controller with automotive grade

The UCC28700-Q1 of flyback power supply

controllers provides Constant-Voltage (CV) and Constant-Current (CC) output

regulation without the use of an optical coupler. The devices process information

from the primary power switch and an auxiliary flyback winding for precise control

of output voltage and current. Low start-up current, dynamically controlled

operating states and a tailored modulation profile support very low standby power

without sacrificing start-up time or output transient response.

Control algorithms in the UCC28700-Q1 allows operating efficiencies to meet or exceed applicable standards. The output drive interfaces to a MOSFET power switch. Discontinuous Conduction Mode (DCM) with valley switching reduces switching losses. Modulation of switching frequency and primary current peak amplitude (FM and AM) keeps the conversion efficiency high across the entire load and line ranges.

The controllers have a maximum switching frequency

of 130 kHz and always maintain control of the peak-primary current in the

transformer. Protection features help keep primary and secondary component stresses

in check. The UCC28700-Q1 allows the level of cable compensation to be

programmed.