US 2003/0142572 A1 · Semiconductor device capable of reliable power-on reset

Abstract

The output of a ring oscillator that receives an internal power supply potential as an operating power supply potential to conduct an oscillation operation is counted by a counter that receives an external power supply potential as an operating power supply potential, and reset is canceled. The circuit that operates with an internal power supply potential can be reliably reset even when the rise of the internal power supply potential is delayed. By adjusting the number of stages of the inverter of a ring oscillator and the number of bits of the counter, the power-on reset time can be adjusted while suppressing increase of the area. An appropriate power-on reset signal can be generated to prevent erroneous operation even in the case where the rise of the internal power supply potential lags behind the rise of the external power supply potential.

Claims8

Dependent claims

A semiconductor device comprising:

a first power supply circuit receiving an external power supply potential to generate a first internal power supply potential;
and
a first power-on reset circuit providing a first reset signal in response to activation of said first internal power supply potential,
said first power-on reset circuit including
a first oscillation circuit conducting oscillation in response to activation of said first internal power supply potential, and
a first count circuit receiving said external power supply potential as an operating power supply potential to effect a count operation in response to an output of said first oscillation circuit, and causing said first reset signal to make a transition from a reset status to a reset cancel status when a count value reaches a predetermined value.

3 more elements

Dependencies are inferred from the claim text.

Semiconductor device capable of reliable power-on reset

Life of this patent

Semiconductor device capable of reliable power-on reset

Life of this patent

Abstract

Claims8