TelCom Semiconductor Inc. (Mountain View, CA) introduced a new series of highly integrated, monolithic, very high voltage, off-line switching regulator circuits, the TC33370 through TC33374. The TC33370 delivers up to 20W from universal inputs, while the TC33374 delivers up to 90W from universal input or 150W with a fixed ac input of 100V, 115V or 230V. The 71/72/73 versions offer power ranges up to 40, 60 and 80W, respectively. The series also features an on-chip 700V Sense FET power switch and a 700V active off-line startup FET eliminating the need for an external startup resistor. The series has an integrated programmable state controller that allows implementation of four on/off control methods of the converter, including primary side manual toggle on/off; secondary side microcontroller toggle on/off, primary side toggle request with secondary side; and programmable on or off state upon application of ac power.