device for the generation and control of a onskad substratpotentialniva on a halvledarmikrokrets

摘要

1462935 Automatic voltage control INTERNATIONAL BUSINESS MACHINES CORP 3 May 1974 [29 June 1973] 19454/74 Heading G3R A plurality of field effect transistors are arranged on a substrate of a semi-conductor chip to which is applied a potential lying outside the range of upper and lower potential levels which are connected across certain of the FET's. The substrate potential is regulated to a desired level. As shown, each one of a series of semiconductor chips 1-N has formed on it a control arrangement for stabilizing the threshold voltages of FET's formed on the chips. Spread in intrinsic threshold voltages, and variations in the power supply to the chips are compensated. In the case of chip 1, a circuit 100 includes a substrate voltage detector 30 comprising a pair of FET's 31, 32 forming a voltage divider connected between earth and a positive supply voltage +V. The junction voltage is compared by an FET 34 with the substrate voltage, producing a signal which controls the conduction of an FET 27 in an inverter 20 receiving a high frequency pulsed input from a ring oscillator 10 also formed on the chip. The inverter produces a further signal to control an FET 41 in a voltage level converter 40 which determines the magnitude of a negative potential connected to the substrate by way of a diode D1.