Logic level converting circuit

Abstract

The invention relates to a logic level converting circuit, which comprises a control end which is connected with an input signal, a first end which is grounded, and a second end which is connected with a second enhancement high-voltage transistor of level output, and also comprises a depletion high-voltage transistor used as a load device, a low-voltage transistor used as an isolating device and a first enhancement high-voltage transistor used as an auxiliary device. In the invention, the (N-Mental-Oxide-Semiconductor) depletion high-voltage transistor is utilized to eliminate the loss of voltage of the logic level without using the high-voltage PMOS (positive channel Metal Oxide Semiconductor) device, and the PMOS low-voltage transistor the grid electrode of which is connected with high level is used as the isolating device to further reduce the grid source voltage of the depletion transistor and increase the threshold value of the depletion transistor, thereby ensuring that no quiescent current is generated when a logic input signal the high level, whereas the NMOS first enhancement high-voltage transistor is used for short-circuit connection with the source leakage end of the low-voltage PMOS device. Analogously, the same effect can also be achieved by changing the NMOS transistor for the PMOS transistor and changing the PMOS transistor for the NMOS transistor.

Description

technical field [0001] The present invention relates to logic level conversion technology, more specifically, relates to a logic level conversion circuit without high voltage PMOS or high voltage NMOS. Background technique [0002] Level shifting is widely used in multi-power supply systems and control systems, especially when using microcontrollers, which usually work at lower power supply voltages, and peripheral devices need to use higher power supply voltages because they actually need to use To level conversion; In addition, in order to reduce physical size and reduce power consumption in mixed-signal integrated circuits, the logic part usually uses low power supply voltage. The power supply voltage of the analog circuit part is determined by the application, so level conversion must be carried out in their interface part. If the converted power supply voltage is high, the interface circuit requires high-voltage devices. Commonly used level shifting circuits such as ...

AI Technical Summary

Problems solved by technology

When the input signal IN is GND, mn2 is turned off. Since mn1 needs at least a voltage drop of its threshold voltage to turn on, the output terminal OUT is pulled up by mn1 to a potential lower than VH, and there is a certain voltage loss in the output level.

When the input signal IN is high level VCC, the output terminal OUT is pulled down to GND by mn2, at this time, the diode-connected mn1 is connected between VH and GND, thereby consuming quiescent current

Images