JPH01241157A - Semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To detect the operating temperature of an LSI in real time through a simple configuration without using a special sensor, by providing an active element for measuring a temperature, thereby mounting measurement terminals so as to take out a voltage drop in the prescribed current density of the active element to the outside. CONSTITUTION:A circuit part 2 which is formed on the substrate 1 of a semiconductor integrated circuit (LSI) is composed of a number of temperature measuring active elements 3 equipped with pn junctions such as transistors, diodes, and the like as well as passive elements such as resistors and the like as occasion demands. As to the temperature measuring active elements 3, measurement extend terminals 4 and 5 for the make of taking out a drop in voltage VBE which occurs in the case where as electric current in the pn junctions flows are formed on the substrate 1. Voltage corresponding to the drop in voltage VBE has a correlation to temperature characteristics on the basis of those of the temperature measuring active elements 3. Thus, the temperature signals of the LSI are detected by using effectively the temperature characteristics of the active elements 3 themselves that are contained in the LSI itself without using a specific temperature sensor.

Description

[Detailed description of the invention] Overview Industrial field of application Conventional technology Problems to be solved by the invention Means for solving the problem Action 1 Example 1 Example (Figs. 2 and 3) Figure) Second embodiment (Figure 4) Third embodiment (Figure 5) Fourth embodiment (Figures 6, 7, 8, 9) Fifth embodiment (Figure 10) Sixth Embodiment (FIG. 11) Seventh Embodiment (FIG. 12) Effects of the Invention [Summary] The present invention relates to conductor integrated circuits (hereinafter referred to as LSI) such as ICs, LSIs, and very large scale integrated circuits (LSIs). In particular, active elements such as transistors and diodes (hereinafter referred to as
It's called a transistor. ), the present invention effectively utilizes the temperature characteristics of the active elements included in the LSI itself without using a special temperature detector. The purpose is to provide an LSI that can extract the temperature signal of the LSI, and in a semiconductor integrated circuit, an active element for temperature measurement having a PN junction and a voltage drop of this active element at a predetermined current density can be outputted to the outside. It was configured with an external measurement terminal.

[Industrial application field]

The present invention relates to semiconductor integrated circuits (hereinafter referred to as LSIs) such as ICs, LSIs, and very large scale integrated circuits (LSIs), and particularly to active elements such as transistors and diodes (hereinafter referred to as "LSIs") formed in LSIs.
It's called a transistor. ) The present invention relates to an LSI that is configured to be able to detect the temperature of the LSI using the following. .

[Conventional technology]

Due to recent advances in semiconductor technology, semiconductor integrated circuits have become ICs.
It has evolved from LSI to super LSI. With this development, the integration density has increased and the operating speed has also increased.

With the increase in density and speed of LSI, one
There is a tendency for power consumption per element to increase and heat generation per chip to increase.

Since the operation of semiconductors is easily affected by heat, heat countermeasures are currently being taken using heat dissipation fins, forced cooling fans, and the like.

[Problem to be solved by the invention]

However, the heat dissipation measures mentioned above are based on the characteristics determined at the design stage of computer systems using LSI, etc.
It did not correspond to actual temperature conditions. Also,
Even in systems with the same design specifications, the temperature conditions of LSIs vary depending on the installation location, length of operation time, etc., and uniform cooling with the same design specifications does not necessarily suit the situation. In order to operate an LSI under good conditions, it is necessary to detect the actual temperature during operation and manage the temperature to always maintain it at an appropriate temperature.

Therefore, as a means for detecting the temperature of the LSI, it is conceivable to attach a temperature sensor such as a thermocouple or thermistor to the LSI mounted inside the system and extract a detection signal from the temperature sensor. However, the wiring and component placement within the system are extremely complex, and it is impossible to place such a temperature sensor in such a limited space due to the horizontal construction of the system, so this is not a realistic solution. do not have.

Furthermore, even if it can be arranged, what can be obtained is the temperature of the surface of the LSI package, and it is not possible to see the temperature of the LSI itself.

An object of the present invention is to provide an LSI that can extract a temperature signal of the LSI by effectively utilizing the temperature characteristics of active elements included in the LSI itself, without using a special temperature detector.

[Means to solve the problem]

FIG. 1 shows a diagram of the principle of the present invention. An LSI includes a semiconductor integrated circuit board 1 and a circuit section 2 formed on the board. The circuit section 2 includes transistors, diodes, etc.
It is configured to include a large number of active elements having N junctions and passive elements such as resistors when necessary. The active elements include a temperature measuring active element 3 according to the present invention.

This temperature measuring active element 3 is not a so-called temperature detecting element such as a thermistor, but has the same structure as an element normally used in LSI. The temperature measuring active element 3 has a PN junction, and an external measuring terminal 4 is used to extract the voltage drop that occurs when a certain current is passed through the PN junction.
5 is formed on the semiconductor integrated circuit substrate 1. As a means for passing current through the PN junction, a constant current source provided within the LSI may be used, or an external measurement terminal 4,
5 and an external constant current source.

[Effect]

When a current is passed through the PN junction of the temperature measuring active element 3, a voltage corresponding to the voltage drop occurring between the PN junctions appears between the external measuring terminals 4.5.

This voltage has a correlation with the temperature characteristics based on the characteristics of the active element 3 for temperature measurement. Therefore, by measuring the voltage between the external measuring terminals 4 and 5, the temperature of the temperature measuring active element 3 can be measured, which means that the temperature of the LSI incorporating the active element 3 during operation is This means that it can be measured.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

Overview] As shown in Figure 1, an LSI semiconductor integrated circuit board (
A circuit section 2 formed on a substrate 1 (hereinafter referred to as a substrate) includes a large number of active elements (hereinafter referred to as transistors) having PN junctions such as bipolar transistors and diodes, and passive elements such as resistors when necessary. It is composed of: The transistors mentioned above include a temperature measuring transistor 3 according to the present invention. This transistor 3 does not have a special structure, and the structure itself is made in the same process as other transistors. however,
Choose as appropriate whether to provide a dedicated transistor for temperature measurement, use a vacant transistor that is not used within the LSI, or use an output buffer transistor provided within the LSI during idle time periods other than during normal operation. .

An external terminal for measurement (hereinafter referred to as a terminal) 4 is connected to the base of the transistor 3, and a terminal 5 is connected to the emitter. Each terminal 4.5 is arranged on an empty space of the substrate 1, and is used to derive a forward voltage drop between the base and emitter of the transistor 3 (hereinafter referred to as base voltage) to the outside.

As a means for flowing collector current to the transistor 3, L
Using an rN source present in the SI or using terminal 5
There are two ways to connect an external constant current source. These will be explained in each embodiment described later.

Next, an overview of the operation will be explained. When a current flows through the PN junction of transistor 3, the base voltage generated at the PN junction ■
BF appears between terminals 4.5. This base voltage ■8E
By measuring , the temperature of the transistor 3 can be measured using equation (1), which will be described later. Since the temperature of the transistor 3 is essentially equivalent to the temperature of the entire LSI, the temperature of the LSI can be known.
It becomes possible to manage the temperature of LSIs placed within the system. There are various uses for this temperature signal, and detailed examples will be described later in the seventh embodiment.

A first embodiment of the present invention will be described with reference to FIGS. 2 to 4.

Now, consider the transistor Tr1 shown in FIG. 2 as the temperature measuring transistor 3. transistor 1゛r1
The collector of is connected to the GND line wired inside the LSI, the emitter is connected to terminal 5, and the base is connected to the GND line via base bias resistor RB and also to terminal 4. Open emitter output method It has become.

-ffi, as shown in Figure 3, the base voltage of the transistor ■8E is the collector current (or current density) of the active region I
It has linear temperature characteristics in a small range of C, and has a predetermined temperature coefficient K.

Therefore, at a certain reference temperature Tjo, the base voltage “BE(T
), then measure the current base voltage “BE(Tjl
In this example, since the transistor Tr1 is fixed biased with a fixed value resistance Re, the current density of the collector current is determined by the base voltage V BE (T jo ), V BE (T'
The same is true for any measurement of ji).

The second embodiment is shown in FIG. 4. The first embodiment (FIG. 2) described above uses the GND line and resistor R8 formed in the LSI to flow the collector current with a fixed bias. , each base voltage v8. (Tjo), v8. (Tjl). On the other hand, in the second embodiment, the transistor 1r2 is provided independently with no electrical connection to other circuits in the LSI. The collectors of transistors 1' and 2 are connected to a separately provided terminal 6, the emitters to terminals 5 and 7, and the bases to terminal 4, respectively.

During measurement, an external current source 8 is connected between the terminals 6 and 7, and a constant current is drawn from the terminal 7 to cause a collector current to flow. When this collector current is flowing, the base voltage generated between terminals 4 and 5 is defined as "BE('r)" at the reference temperature and "vB" at the time of measurement, as in the first embodiment.
O is measured for E(Tjl) and converted using equation (1).

In this way, by separately attaching the constant current source 8 externally and providing a separate terminal for connecting it, it is possible to suppress errors caused by the terminal 5 and its wiring resistance. In other words,
In the case of the first embodiment, since the terminal 5 for measuring the base voltage is present in the flow path of the collector current, the terminal 5 is connected to the base voltage.
However, in the second embodiment, the terminal 4.5 is provided separately from the current path, so the base voltage drop is included.
It is excellent in that it can extract the voltage drop only between the emitters. However, the first embodiment has a simpler structure and is advantageous for simple measurements.

A third embodiment is shown in FIG. Transistor Tr4 and resistor R81 constituting the current source are integrated into LSI
It is pre-wired internally. vcs is the bias voltage of the transistor Tr4.

Temperature measurement is based on the base voltage VBE (
'T''j(1) and VBE (Tjt) are each measured and converted using equation (1).

According to this third embodiment, the terminals to be derived are 2 of 4 and 5.
Moreover, since there is no voltage loss at the terminal 5, highly accurate measurement is possible.

The first to third embodiments described above are based on the assumption that the current density is the same, and the base voltages V8. (Tjo), VB, (Tjl
) was measured and converted into temperature using equation (1).

However, in this method, it was necessary to measure the specific VBE in advance while setting TJO or J1 as a reference temperature. Moreover, the vBE at the standard temperature is a value unique to each device, and must be prepared for each device.

However, as shown in FIG. 6, the temperature coefficient of a transistor has a characteristic that it varies depending on the current density. This characteristic cancels the variation in V8 [ mentioned above,
Each device has almost the same characteristics.

Therefore, in this embodiment, as the temperature measuring transistor 3 (FIG. 1), two transistors Tr5. "r6, each transistor Tr5.Tr6
The difference between the base voltages is calculated and the difference voltage is converted into temperature.

As shown in FIG. 7, the first transistor 'rr5, the second
The bases of the transistors Tr6 are connected in common, are fixedly biased by a bias resistor Re, and are connected to the terminal 1.
6 to a constant current source 9 . A constant current source 10 is connected to the emitter of the first transistor Tr5 via a terminal 4.
A constant current source 11 is connected to the emitter of the second transistor "r6 via a terminal 5."

Although the current densities of the first transistor Tr5 and the second transistor Tr6 are different from each other, there are two methods for adjusting the current density. One is the area S, 3 of each emitter of the first transistor 1r5 and the second transistor Tr6.
6 to be different from each other (for example, S5 x S6), and the other one is to make the constant current source 10.1 with the same emitter area.
By making each current of 1 different, the collector current I
, I are mutually different (for example, I5>I6).

It may be selected as appropriate.

In the above circuit, it is assumed that the current density of the first transistor Tr5 is larger than the current density of the second transistor Tr6, and the base voltage vB of the first transistor Tr5 is
Let us look at the characteristics when the temperature of E5 and the base voltage BE6 of the second transistor Tr6 is changed.

The characteristics are shown in FIG. 8.As shown in FIG. 8, the base voltages and vBE6 become different as the temperature rises to BF2CP. As mentioned above, this is due to the change in temperature coefficient due to the difference in current density.

Therefore, the base voltage of the first transistor r5 is
By measuring the difference between the base voltage of the second transistor Tr6 and the base voltage of the second transistor Tr6, the accurate temperature of the LSI can be directly detected.

A fifth embodiment is shown in FIG. 10. This embodiment uses two transistors Tr5. Two diodes D instead of Tr6
, D2''.

The diodes D1 and D2 are formed by short-circuiting the base and collector of transistors, but elements formed as diodes from the beginning, such as Schottky barrier diodes, may also be used.

tJlil, each diode D1. Connect the cathode of D2 (corresponding to the emitter of the transistor) to terminal 4.
．． 5 and form it.

The measurement method and principle are the same as in the fourth embodiment, with constant current sources 12 and 13 connected to terminals 4 and 5, respectively, and output voltages V at terminals 4 and 5. 1. ■ Difference in o2 (Vol-■,
Temperature detection is possible by determining 2). Other detailed explanations will be omitted.

A sixth embodiment is shown in Fig. 11. In this embodiment, two current density states are created by switching the current of one diode D3 as the temperature measuring transistor 3 (Fig. 1). , the base voltage at each current density is measured.

As in the case of the fifth embodiment, the diode D3 may be an element formed by short-circuiting the base and collector of a transistor formed in the LSI (Fig. 11), or an element formed by short-circuiting the base and collector of a transistor formed in the LSI, or an element formed by short-circuiting the base and collector of a transistor formed in the LSI, or an element formed from the beginning like a Schottky barrier diode. Assume that an element formed as a diode is used.

′! In the f4 structure, G in the LSI is connected to the anode (collector, base) of diode D3.
The ND wire is led out to terminal 4, and the cathode (that is, the emitter) is led out to terminal 5.

In the measurement, the changeover switches SW are connected to different constant current sources 14 and 15, and the measurement is performed twice by switching the switches alternately. Then, the base voltages v and v at each measurement time are
The difference (■14-''15) is calculated and converted to temperature according to FIG.

According to this embodiment, only one diode D3 is required, and since the terminal 4 can also be used as the GND terminal originally provided in the LSI, only the newly provided terminal 5 is required, resulting in a simple configuration. This has the advantage that the present invention can be implemented.

Eaves Dog Cliff 1 Each of the first to sixth embodiments described above is an example regarding the transistor 3 for temperature measurement.Next, a temperature management system of an LSI in which the transistor 3 for temperature measurement is mounted will be explained. do.

FIG. 12 shows the seventh embodiment. Computer system 17
It is assumed that an LS 118 having a built-in temperature measuring transistor 3 according to the present invention is used as one of the constituent elements. The base voltage (i.e., temperature detection signal) output from the transistor 3 is input to one temperature control device, A/D converted, and compared with a predetermined reference temperature (optimum operating temperature), and its deviation is calculated. A control signal corresponding to the cooling fan 20
is given to the temperature, and the temperature is feedback-controlled to the appropriate temperature.

It is also possible to set a reference temperature for abnormal temperature monitoring and to output an alarm 21 in case of abnormal temperature.

Alternatively, it is also possible to provide the output voltage from transistor 3 of the LS118 as data for statistical processing, and based on that data, it is possible to construct a more suitable system by using it as design material for the cooling section of the system. Become.

〔Effect of the invention〕

As described above, according to the present invention, an active element for temperature measurement is provided in a semiconductor integrated circuit, and a measurement terminal is provided for deriving the voltage drop of this active element at a predetermined current density to the outside. Therefore, the operating temperature of the LSI can be detected in real time with a simple configuration without using a special temperature sensor, and the temperature of the LSI can be managed based on the information.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the principle of the present invention, Fig. 2 is a circuit diagram showing a first embodiment of the invention, Fig. 3 is a temperature characteristic diagram of base voltage, and Fig. 4 is a diagram showing a second embodiment of the invention. 5 is a circuit diagram showing a third embodiment of the present invention, FIG. 6 is a characteristic diagram of the temperature coefficient of base voltage with respect to current density, and FIG. 7 is a circuit diagram showing a fourth embodiment of the present invention. , Fig. 8 is a temperature characteristic diagram of each base voltage in the fourth embodiment, Fig. 9 is a temperature conversion characteristic diagram of potential difference in the fourth embodiment, Fig. 10 is a circuit diagram showing the fifth embodiment, Fig. 11 12 is a circuit diagram not showing the sixth embodiment, and FIG. 12 is a circuit diagram showing the seventh embodiment. DESCRIPTION OF SYMBOLS 1... Semiconductor integrated circuit board, 2... Circuit section, 3... Active element for temperature measurement, 4... External terminal for measurement, 5... External terminal for measurement. ,;,,,4mi,-・ ゝ +0. / Figure 11 Single 12 figures

Claims (1)

[Claims] In a semiconductor integrated circuit, an active element (3) for temperature measurement having a PN junction and external measuring terminals (4, 5) led out to the outside for measuring the voltage drop (V_B_E) at a predetermined current density of this active element are used. ) and an integrated circuit.