PRECISE HYSTERESIS CIRCUIT

摘要

PURPOSE: To obtain a CMOS circuit structure having a differential switch point accurately balanced. CONSTITUTION: Voltage followers for generating a reference voltage are provided at the both ends of an on-chip reference resistor RO. A generated current reflects and flows via plural on-chip resistors R1 to R8. A reflective current flowing via the plural resistors generates plural proportional reference voltages. A switching threshold value is set to one input of a comparator 20 using two of the proportional reference voltages. The output of the comparator 20 is fed back to control a switch 18 for selecting one of two voltages. Another proportional reference voltage is combined with other input of the comparator 20. When a positive and a negative threshold values are selected, a hysteresis circuit is formed in a circuit structure.