US 5,844,853 A · Memory regulator control method with flexibility for a wide change in supply voltage

Abstract

A circuit and method for providing a plurality of voltage regulators whose outputs are constant for ranges of different external voltages are disclosed. The voltage regulators are made to be adaptable to two different ranges of external voltages through use of a master-slice technique. Furthermore, in a first voltage regulator, the supply current capability of the regulator is significantly increased under very low external voltage conditions. In a second voltage regulator, the voltage level on any node of the regulator does not exceed a voltage level that is too high, yet still sinks most of its current from the external power supply. A third voltage regulator is able to charge and discharge its output voltage so that it will maintain at a constant level. Finally, a fourth voltage regulator is optimized to reduce dielectric leakage.

Claims37

Dependent claims

A semiconductor memory produced using a plurality of mask layers, the semiconductor memory comprising:

a plurality of memory cells;
a plurality of output circuits;
a plurality of peripheral circuits;
a first external pad for receiving an external positive supply voltage, a level of the external positive supply voltage being in one of either a first operating voltage range or a second operating voltage range, wherein the second operating voltage range is higher than the first operating voltage range;
a second external pad for receiving an external ground supply voltage;
a first voltage regulator generating a first output voltage for the memory cells;
and
a second voltage regulator generating a second output voltage for the peripheral circuits, the second voltage regulator comprising:
a first output transistor, a second output transistor, a first circuit which activates the first output transistor in response to a drop in the second output voltage, and a second circuit which activates the second output transistor in response to the level of the external positive supply voltage being in the first operating voltage range;
wherein a first mask layer is used if the external positive supply voltage level is intended to operate in the first operating voltage range, the first mask layer shorting the first and second output transistors of the second voltage regulator;
wherein a second mask layer is used if the external positive supply voltage level is intended to operate in the second operating voltage range;
such that when the external positive supply voltage level is in the first operating voltage range, the first output voltage level is substantially constant in spite of fluctuations of the external Positive voltage level and the second output transistor is activated so that the second output voltage is connected to the external positive supply voltage through the second output transistor, and when the external positive supply voltage level is in the second operating voltage range, levels of the first and second output voltages are substantially constant in spite of fluctuations of the external positive voltage level, the second output transistor is disabled and the second output voltage is selectively connected to the positive supply voltage through the first output transistor in response to a drop in the second output voltage.

9 more elements

Dependencies are inferred from the claim text.

Memory regulator control method with flexibility for a wide change in supply voltage

Life of this patent

Memory regulator control method with flexibility for a wide change in supply voltage

Life of this patent

Abstract

Claims37