| 摘要 |
PURPOSE:To accelerate the compensation of a bias variation by increasing a variation in the threshold voltage to a variation in a substrate potential of MOSFET of a driver and a load for forming an inverter when a substrate bias generator is formed of ring oscillators connected continuously with a plurality of MOS inverters and charge pump circuits driven by the oscillators. CONSTITUTION:Ring oscillator OSC is composed of n-stage continuous connection of E/E type MOS inverters, and a stable substrate bias voltage Vsub is obtained by two charge pumps CP1, CP2 driven by different outputs 1, 2 of 180 deg. of phase. In this structure, the channel length L2 of an element Q2i of a load MOSFET element Q1i(i=1-n) of components of the oscillator OSC and driver MOSFET element Q2i is formed longer than the channel length L1 of the element Q1i, and when the substrate potential varies, the oscillating frequency of the oscillator OSC is largely varied in the variation compensating direction. |
