US 7,233,175 B2Granted

Amplitude limiting circuit

AssigneeOki Electric Industry Co., Ltd.

InventorTadamasa Murakami

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Abstract

An amplitude limiting value can be set to an intended value of a designer and the dependence of the amplitude limiting value on the temperature can be avoided. An amplitude limiting circuit according to the present invention includes a pair of first conductivity type MOS transistors provided in a diode-connected configuration, which is connected between one output terminal of a differential circuit and the other output terminal thereof, a first source follower circuit comprising second conductivity type first and second MOS transistors connected in series between a first power supply and a second power supply, a second source follower circuit comprising second conductivity type third and fourth MOS transistors connected in series between the first power supply and the second power supply, and a current supply circuit comprising a current source that outputs a current proportional to an absolute temperature and a resistor both of which are connected in series between the first power supply and the second power supply.

Claims6

Dependent claims

An amplitude limiting circuit, comprising:

a differential circuit which comprises a first transistor having a control electrode, a first electrode connected to a first node and a first output node and a second electrode connected to a second node and a second output node, a second transistor having a control electrode, a first electrode connected to the first output node and a second electrode connected to the second output node, a third transistor having a control electrode connected to a first input node, a first electrode connected to the first electrode of the second transistor and a second electrode, and a fourth transistor having a control electrode connected to a second input node, a first electrode connected to the second electrode of the second transistor and a second electrode connected to the second electrode of the third transistor;
a first source follower circuit which is connected to the first node and the control electrode of the second transistor, said first source follower circuit comprising a fifth transistor having a control electrode connected to the first node, first electrode supplied with a power supply voltage and a second electrode connected to the control electrode of the second transistor;
and a first current source connected to the second electrode of the fifth transistor and supplied with a ground voltage;
and
a second source follower circuit which is connected to the second node and the control electrode of the first transistor, said second source follower circuit comprising a sixth transistor having a control electrode connected to the second node, a first electrode supplied with the power supply voltage and a second electrode connected to the control electrode of the first transistor;
and a second current source connected to the second electrode of the sixth transistor and supplied with the ground voltage;
wherein the differential circuit further comprises:
a third current source connected to the second electrodes of the third and fourth transistors and supplied with the ground voltage.

5 more elements

An amplitude limiting circuit comprising:

a differential circuit which comprises a first transistor having a control electrode, a first electrode connected to a first node and a first output node and a second electrode connected to a second node and a second output node, a second transistor having a control electrode, a first electrode connected to the first output node and a second electrode connected to the second output node, a third transistor having a control electrode connected to a first input node, a first electrode connected to the first electrode of the second transistor and a second electrode, and a fourth transistor having a control electrode connected to a second input node, a first electrode connected to the second electrode of the second transistor and a second electrode connected to the second electrode of the third transistor;
a first source follower circuit which is connected to the first node and the control electrode of the second transistor, said first source follower circuit comprising a fifth transistor having a control electrode connected to the first node, a first electrode supplied with a power supply voltage and a second electrode connected to the control electrode of the second transistor;
and a sixth transistor having a control electrode, a first electrode supplied with a ground voltage and a second electrode connected to the second electrode of the fifth transistor;
a second source follower circuit which is connected to the second node and the control electrode of the first transistor, said second source follower circuit comprising a seventh transistor having a control electrode connected to the second node, a first electrode supplied with the power supply voltage and a second electrode connected to the control electrode of the first transistor;
and an eighth transistor having a control electrode connected to the control electrode of the sixth transistor, a first electrode supplied with the ground voltage and a second electrode connected to the second electrode of the seventh transistor;
a first current source connected to the control electrode of the eighth transistor and supplied with the power supply voltage;
and
a resistor connected to the control electrode of the eighth transistor and supplied with the ground voltage;
wherein the differential circuit further comprises:
a second current source connected to the second electrodes of the third and fourth transistors and supplied with the ground voltage.

7 more elements

An amplitude limiting circuit, comprising:

a differential circuit which comprises
a first output node;
a second output node;
a first node;
a second node connected to the second output node;
a first transistor having a control electrode, a first electrode connected to the first output node and the first node and a second electrode connected to the second node;
a second transistor having a control electrode, a first electrode connected to the first output node and a second electrode connected to the second electrode of the first transistor;
a third transistor having a control electrode connected to a first input node, a first electrode connected to the first electrode of the second transistor and a second electrode;
a fourth transistor having a control electrode connected to a second input node, a first electrode connected to the second electrode of the second transistor and a second electrode connected to the second electrode of the third transistor;
a first source follower circuit which is connected to the first node and the control electrode of the second transistor, said first source follower circuit comprising a fifth transistor having a control electrode connected to the first node, a first electrode supplied with a ground voltage and a second electrode connected to the control electrode of the second transistor;
and a first current source connected to the second electrode of the fifth transistor and supplied with a power supply voltage;
and
a second source follower circuit which is connected to the second node and the control electrode of the first transistor, said second source follower circuit comprising a sixth transistor having a control electrode connected to the second node, a first electrode supplied with the around voltage and a second electrode connected to the control electrode of the first transistor;
and a second current source connected to the second electrode of the sixth transistor and supplied with the power supply voltage;
wherein the differential circuit further comprises:
a third current source connected to the second electrodes of the third and fourth transistors and supplied with the ground voltage.

13 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/944,754Filed 21 Sep 2004
Priority: JP 2004-0640778 Mar 2004
Published: US 2005/0194997 A18 Sep 2005
Granted: 19 Jun 2007
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

H03F 3/45183
Using MOSFET transistors as the active amplifying circuit: long tailed pairs
H03G 1/0029
The device being at least one of the amplifying solid-state elements: using field-effect transistors [FET]
H03G 11/002
Limiting amplitude; Limiting rate of change of amplitude: without controlling loop
H03K 5/08
Shaping pulses: by limiting; by thresholding; by slicing, i.e. combined limiting and thresholding