Logic level voltage translator

Abstract

A voltage level translator provides an output signal having an external voltage in response to an input signal having an internal voltage. The voltage level translator includes first and second input signal transistors, first and second output signal transistors, and includes a signal stabilization circuit and / or an enable circuit. A ready-signal generation circuit provides a ready signal indicating that a voltage supply is at an operating voltage. The ready-signal generation circuit can include unbalanced transistors.

Description

BACKGROUND OF INVENTION [0001] 1. Field of Invention [0002] The invention relates to operating voltage levels of integrated circuits. In particular, the invention relates to apparatus and methods for translating voltage levels of signals traveling between integrated circuits that operate at different voltage levels. [0003] 2. Discussion of Related Art [0004] Electronic systems often include circuits that operate at relatively low voltages, at times including core logic circuits and memory circuits, and other circuits that operate at higher voltages. Such mixed-mode voltage systems typically require voltage translation and voltage clamping capabilities. Voltage translation components allow proper communication of the I / O signals traveling between circuits operating at different voltage levels. [0005] Circuits that employ transistors having smaller gate dimensions typically require an associated decrease in supply voltage level. Microprocessors and memory circuits, for example, often ...

AI Technical Summary

Benefits of technology

[0011] The translator can further include first and second high voltage transistors that each have essentially zero threshold voltage and mediate the connection between the first and second input signal transistors and the first and second output signal transistors. The translator can further include a cascode circuit. The zero-threshold transistors and the cascode circuit can protect the drains of the first and second input signal transistors from the external voltage.

Problems solved by technology

Unfortunately, a level-shifting circuit may fail to function properly when an internal voltage supply is producing less than its full operating voltage.

Moreover, level-shifting circuits can introduce distortions and / or delays in the low-voltage signals that they convert to high-voltage signals.

Images