Oscillation circuit

Abstract

Abstract PURPOSE:To obtain a low oscillation frequency by a simple circuit without increasing a chip size, by using a constant current circuit as a charging means. CONSTITUTION:A conventional resistor is replaced by a PMOS4. In other words, after an NMOS5 being turned off, a capacitor is charged by a constant current via the PMOS4, and its potential rises gradually. And inverters 1 and 2 are inverted, then, the potential goes down to the GND side via the turned on NMOS5. Oscillation occurs by repeating such operation hereafter. Thus, by using the constant current circuit as the charging means, it is possible to set the oscillation frequency by the current value of the constant current circuit, and to obtain a near oscillation frequency only by setting the current value at a low level. Furthermore, since the capacitance of a capacitor can be reduced by reducing the current value, it is possible to reduce the area of the capacitor.

Inventors

• 👤 Noritaka Nishikawa

Bibliographic Details