Signal output circuit and semiconductor integrated circuit

Abstract

A signal output circuit is disclosed that supplies a signal from a first circuit that is driven based on a first reference voltage to a second circuit that is driven based on a second reference voltage. The signal output circuit includes a first control circuit that draws a current to the first reference voltage according to an output signal from the first circuit and supplies a signal to the second circuit according to the drawn current, and a second control circuit that draws a current from the second circuit to the second reference voltage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a configuration of an integrated circuit according to an embodiment of the present invention;

FIG. 2 is a circuit diagram of a signal output circuit according to an embodiment of the present invention;

FIGS. 3A and 3B are diagrams illustrating operational waveforms of the signal output circuit; and

FIGS. 4A and 4B are diagrams showing exemplary configurations of integrated circuits.

Claims

1. A signal output circuit that supplies a signal from a first circuit that is driven based on a first reference voltage to a second circuit that is driven based on a second reference voltage, the circuit comprising: a first control circuit that draws a current to the first reference voltage according to an output signal from the first circuit, and supplies a signal to the second circuit according to the drawn current; anda second control circuit that draws a current from the second circuit to the second reference voltage.

2. The signal output circuit as claimed in claim 1, wherein the first control circuit includes a first transistor that draws a current to the first reference voltage according to the output signal from the first circuit, and a second transistor that supplies a current to the second circuit according to the current drawn by the first transistor.

3. The signal output circuit as claimed in claim 1, wherein the second control circuit includes a transistor that draws the current from the second circuit to the second reference voltage.

4. The signal output circuit as claimed in claim 1, wherein the first reference voltage is a ground voltage; andthe second reference voltage is a negative voltage.

5. The signal output circuit as claimed in claim 1, wherein the first circuit is an IIL circuit that is driven based on the first reference voltage; andthe second circuit is an analog circuit that is driven based on the second reference voltage.

6. A semiconductor integrated circuit comprising: a first circuit that is driven based on a first reference voltage;a second circuit that is driven based on a second reference voltage;a first control circuit that draws a current to the first reference voltage according to an output signal from the first circuit; anda second control circuit that draws a current from the second circuit to the second reference voltage.