摘要 |
PURPOSE: To enable a shunt regulator for adjusting a programming voltage on a program line to automatically adapt to a change in the manufacturing process of a programmable device using the voltage, to achieve a long life, and to operate with a small power. CONSTITUTION: A shunt regulator has an adjustment transistor 66 that is connected between a program line 10 and the first power supply of a fixed potential, a voltage divider that has a connection point 48 being connected for controlling the transistor 66 and includes a tunnel structure 52 and a capacitor 50, and a second capacitive voltage divider consisting of capacitors 18 and 20 being connected between a second potential power supply +V and the program line 10 for controlling a potential in the connection point 48 in response to the program line 10. Also, these devices including the tunnel structure 52 are formed by the same manufacturing process on the same semiconductor substrate as a programmable device using a regulation voltage. |