摘要 |
A level shifting circuit includes a string of diodes and an active load across which the control voltage is applied. A resistor is coupled across the lowermost diode to develop a switch control voltage. At low control voltage, the diode string allows no current to be developed across the resistor. At higher control voltage, the diodes conduct and the active load takes up the difference between the control voltage and the diode string voltage. A switch responds to the resistor voltage, for switching a load On and OFF. A second active load takes up excess load supply voltage. |