JP2010216810A5

JP2010216810A5 -

Info

Publication number: JP2010216810A5
Application number: JP2009060476A
Authority: JP
Filing date: 2009-03-13
Publication date: 2012-04-12
Anticipated expiration: 2029-03-13

Description

上記目的を達成するために、請求項１にかかる発明の温度検出回路は、第１の抵抗を含み、該第１の抵抗の抵抗値に反比例する第１の電流を生成する第１の電流生成回路と、第２の抵抗を含み、該第２の抵抗の抵抗値の２乗に反比例する第２の電流を生成する第２の電流生成回路と、前記第１の電流を第３の抵抗に流して、温度に依存しない第１の電圧を生成する第１の電圧生成回路と、前記第２の電流を第４の抵抗に流して、温度に応じて変化する第２の電圧を生成する第２の電圧生成回路と、前記第１の電圧と前記第２の電圧とを比較するコンパレータとを備えたことを特徴とする。
請求項２にかかる発明は、請求項１記載の温度検出回路において、前記第２の電圧生成回路が、直列に接続した前記第４の抵抗と第５の抵抗とに前記第２の電流を流して、前記第２の電圧に加えて、温度に応じて前記第２の電圧と同様に変化する第３の電圧を生成するものであり、前記コンパレータに加えて、前記第１の電圧と前記第３の電圧とを比較する第２のコンパレータを備えたことを特徴とする。
請求項３にかかる発明は、請求項１または２記載の温度検出回路において、前記第１の電流生成回路がＢＧＲ回路であり、前記第２の電流生成回路がＧｍ一定回路であることを特徴とする。
請求項４にかかる発明の温度検出回路は、ＢＧＲ回路の出力段の電流がミラーされる第１のトランジスタと、Ｇｍ一定回路の出力段の電流がミラーされる第２のトランジスタと、前記第１のトランジスタのドレインに接続された第１の抵抗と、前記第２のトランジスタのドレインに直列接続された第２および第３の抵抗と、前記第１の抵抗と前記第１のトランジスタのドレインの共通接続点である第１の共通接続点の電圧と前記第２の抵抗と前記第２のトランジスタのドレインの共通接続点である第２の共通接続点の電圧とを比較する第１のコンパレータと、前記第１の共通接続点の電圧と前記第２の抵抗と前記第３の抵抗の共通接続点である第３の共通接続点の電圧とを比較する第２のコンパレータとを備え、前記第１のコンパレータの出力電圧と前記第２のコンパレータの出力電圧との組合せにより、現在の温度を検出することを特徴とする。 To achieve the above object, a temperature detection circuit according to a first aspect of the present invention includes a first resistor, and generates a first current that is inversely proportional to the resistance value of the first resistor. A second current generating circuit that includes a circuit, a second resistor, and generates a second current that is inversely proportional to the square of the resistance value of the second resistor; and the first current is used as the third resistor. A first voltage generating circuit that generates a first voltage that does not depend on temperature, and a second voltage that generates a second voltage that varies depending on the temperature by flowing the second current through a fourth resistor. And a comparator for comparing the first voltage with the second voltage .
According to a second aspect of the present invention, in the temperature detection circuit according to the first aspect, the second voltage generation circuit passes the second current through the fourth resistor and the fifth resistor connected in series. In addition to the second voltage, a third voltage that changes in the same manner as the second voltage according to temperature is generated. In addition to the comparator, the first voltage and the first voltage are generated. And a second comparator for comparing the voltage with the third voltage.
The invention according to claim 3 is the temperature detection circuit according to claim 1 or 2, wherein the first current generation circuit is a BGR circuit, and the second current generation circuit is a Gm constant circuit. To do.
According to a fourth aspect of the present invention, there is provided a temperature detection circuit comprising: a first transistor in which a current of an output stage of a BGR circuit is mirrored; a second transistor in which a current of an output stage of a Gm constant circuit is mirrored; A first resistor connected to the drain of the second transistor; a second and third resistor connected in series to the drain of the second transistor; and a common of the drain of the first resistor and the first transistor A first comparator for comparing a voltage at a first common connection point, which is a connection point, with a voltage at a second common connection point, which is a common connection point between the second resistor and the drain of the second transistor; A second comparator for comparing a voltage at the first common connection point with a voltage at a third common connection point that is a common connection point between the second resistor and the third resistor; Comparator output The combination of the voltage and the output voltage of the second comparator, and detects the current temperature.

図５にＧｍ一定回路２の一例を示す。このＧｍ一定回路２は、ＰＭＯＳトランジスタＭＰ２１，ＭＰ２２，ＮＭＯＳトランジスタＭＮ２１〜ＭＮ２３、抵抗Ｒ２１，Ｒ２２からなる。トランジスタＭＮ２２はトランジスタＭＮ２１に対して面積比がＫ倍である。このとき、トランジスタＭＰ２３を流れる電流Ｉ₂は、

となる。抵抗Ｒ２１の温度依存性により、Ｉ₂∝１／Ｔ²となる。ここで、μpは移動度、Coxはゲート容量、Ｗ，Ｌはゲート幅およびゲート長である。トランジスタＭＰ２のゲートには電圧Ｖ２が入力されており、トランジスタＭＰ２２とカレントミラー回路が形成されて、トランジスタＭＰ２３の電流Ｉ₂がミラーされてトランジスタＭＰ２を流れる電流も、Ｉ₂₂∝１／Ｔ²となる。 FIG. 5 shows an example of the Gm constant circuit 2. The Gm constant circuit 2 includes PMOS transistors MP21 and MP22, NMOS transistors MN21 to MN23, and resistors R21 and R22. The area ratio of the transistor MN22 is K times that of the transistor MN21. At this time, the current I ₂ flowing through the transistor MP23 is

It becomes. Due to the temperature dependence of the resistor R 21 , I ₂ ∝1 / T ² . Here, μp is mobility, Cox is gate capacitance, W and L are gate width and gate length. The voltage V2 is input to the gate of the transistor MP2, a current mirror circuit is formed with the transistor MP22, the current I _{2 of the} transistor MP23 is mirrored, and the current flowing through the transistor MP2 is also I ₂₂ ∝1 / T ² . Become.

Claims

A first current generating circuit that includes a first resistor and that generates a first current that is inversely proportional to the resistance value of the first resistor; and a second resistor that is 2 of the resistance value of the second resistor A second current generation circuit for generating a second current inversely proportional to the power;
A first voltage generation circuit that generates a first voltage that does not depend on temperature by flowing the first current through a third resistor, and a second voltage that flows through the fourth resistor according to the temperature. A second voltage generating circuit for generating a second voltage that changes
A temperature detection circuit comprising: a comparator that compares the first voltage with the second voltage .

The second voltage generation circuit causes the second current to flow through the fourth resistor and the fifth resistor connected in series, and in addition to the second voltage, the second voltage generator circuit according to the temperature. A third voltage that changes in the same manner as the voltage of
The temperature detection circuit according to claim 1, further comprising a second comparator that compares the first voltage with the third voltage in addition to the comparator.

3. The temperature detection circuit according to claim 1, wherein the first current generation circuit is a BGR circuit, and the second current generation circuit is a Gm constant circuit.

A first transistor that mirrors the output stage current of the BGR circuit, a second transistor that mirrors the output stage current of the Gm constant circuit, and a first resistor connected to the drain of the first transistor; And a voltage at a first common connection point, which is a common connection point between the first resistor and the drain of the first transistor, and a second and third resistor connected in series to the drain of the second transistor. A first comparator for comparing a voltage at a second common connection point, which is a common connection point between the second resistor and the drain of the second transistor, and a voltage at the first common connection point A second comparator for comparing a voltage at a third common connection point that is a common connection point of the second resistor and the third resistor;
A temperature detection circuit for detecting a current temperature based on a combination of an output voltage of the first comparator and an output voltage of the second comparator.