JP2884914B2 - Semiconductor integrated circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit which is used in a semiconductor integrated circuit, and more particularly to a semiconductor integrated circuit which consumes a large amount of power in the semiconductor integrated circuit.

[0002]

2. Description of the Related Art The power that can be consumed by a semiconductor integrated circuit (hereinafter referred to as an LSI) is such that the temperature of a silicon substrate as a semiconductor substrate of the LSI is a certain temperature (usually 125 ° C.).
The maximum ambient temperature guaranteed by the LSI and the thermal resistance of the LSI package are determined as follows so as not to exceed C). Here, the temperature of the semiconductor substrate is defined, for example, by the junction temperature of the built-in PN junction diode. (Hereinafter, the temperature of the semiconductor substrate is simply referred to as the junction temperature.) Po (max) = [Tj (max) -Ta (max)]
/ Rth where Po (max): maximum power consumption, Tj (ma
x): maximum junction temperature Ta (max): maximum ambient temperature, Rth: thermal resistance of the package.

The thermal resistance of a package can be classified into thermal resistance from the surface of the silicon substrate to the surface of the package, and thermal resistance from the surface of the package to the atmosphere and the periphery of a printed circuit board on which the LSI is mounted. The thermal resistance from the surface of the silicon substrate to the surface of the package tends to decrease as the chip size of the LSI increases and the heating area increases. It tends to vary greatly depending on the material of the printed circuit board and the wiring on the board.

However, at present, thermal resistance cannot be calculated for each state of all LSIs, such as the chip size of the LSI, the material of the printed circuit board on which the LSI is mounted, and the wiring on the circuit board. Thermal resistance is measured for each package under the most severe conditions, and the maximum power consumption of the LSI is determined from the results.

A digital signal L for handling digital signals
In the SI, the number of transistors operating in the semiconductor integrated circuit greatly differs depending on the input signal. However, it is difficult to properly calculate the number of operating transistors for all input signals. That is,
Power consumption is estimated based on an input signal at which the number of operating transistors is maximized.

FIG. 7 is a block diagram showing an example of a conventional LSI.

This conventional LSI 20 has a plurality of four circuit blocks 1. No means for detecting the junction temperature is provided.

[0008]

In a method of measuring the thermal resistance for each package in the conventional LSI and determining the maximum power consumption that can be used by the LSI, the thermal resistance at the time of mounting the printed circuit board on which the LSI is actually used is known. Is difficult to accurately estimate, the thermal resistance is usually determined under the condition considered to be the severest, and when designing an LSI that consumes a large amount of power, a design suitable for the operating state is performed. If this is possible, there is a problem that functions that can be integrated originally cannot be built in.

The maximum power consumption of a digital LSI is determined by the minimum operating power supply voltage (hereinafter referred to as V _DD) of the digital LSI.
That. ) And power supply current (hereinafter referred to as I _DD )
Threshold voltage of the OS transistor for (hereinafter, referred to. V _T) and, as shown in FIGS. 8 and 9, V _T
In consideration of the fact that I _DD tends to increase and V _DD tends to decrease when the absolute value of I _D decreases, and that I _DD tends to increase when the number of operating transistors increases, all the worst conditions are determined. Therefore, there is a problem that if the design can be performed in accordance with the operating conditions, the functions that can be originally integrated cannot be incorporated.

It is an object of the present invention to solve the above-mentioned problems and to provide an LSI which enables a thermal design adapted to an operation state and which can incorporate the maximum functions.

[0011]

According to the present invention, there is provided a semiconductor integrated circuit having an electronic circuit formed on one main surface of a semiconductor substrate. A temperature detector for detecting a surface temperature is provided.

Further, according to the present invention, a plurality of the temperature detectors are provided, and the detection data from the plurality of the temperature detectors are switched to a detection data output terminal in response to a detection mode switching signal input from the outside. A detection unit switching circuit is provided.

Further, according to the present invention, a plurality of the temperature detecting sections are provided, and the temperature detecting section is adjacent to a circuit block having the highest temperature.
And detecting the data comparator circuit for selecting detection data from the temperature detecting section is a detection unit that outputs the detected data output terminal switching detection data from a plurality of the temperature detecting section by comparing the results of the detection data comparison circuit And a switching circuit.

Further, according to the present invention, the semiconductor integrated circuit may have an M
An OS transistor, and a plurality of the temperature detectors are provided , adjacent to a circuit block having the highest temperature.
And detecting the data comparator circuit for selecting detection data from the temperature detection unit that, the threshold voltage detection unit that detects the threshold voltage of the MOS transistor, a plurality of circuits included in the semiconductor integrated circuit A power supply unit for supplying power to the block, and a voltage for controlling a power supply voltage supplied from the power supply unit to the circuit block based on data from the detection data comparison circuit and data from the threshold voltage detection unit. And a control circuit.

Further, the present invention is characterized in that a control data storage unit in which a control algorithm of the voltage control circuit is stored in advance is provided.

[0016]

According to the present invention, since a temperature detecting section comprising a PN junction diode, for example, for measuring the junction temperature of an LSI is provided, the junction temperature of an actual LSI can be measured in accordance with the operation state. Adaptable optimal thermal design can be performed, and it is possible to incorporate maximum functions.

When there are a plurality of circuit blocks to be measured, a temperature detecting section is provided for each circuit block, and the detecting section switching circuit is connected to the detection data output terminal by a detection mode switching signal or a comparison result of the detection data comparing circuit. Since the output is performed, the temperature can be detected with a smaller number of output terminals.

Furthermore, in the digital LSI which is composed of MOS transistors, and the temperature detection data, by controlling the supply voltage on the basis of the data of the detected V _T by the threshold voltage detection unit, V occurring in the manufacturing process
_It is possible to correct the variation in _T and control the power consumption in a state where the LSI is actually used.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the present invention, and FIG. 2 is a diagram showing a part of the first embodiment in detail.

In the first embodiment, in an LSI 20a having a plurality of four circuit blocks 1 formed on a silicon substrate, the surface temperature of the silicon substrate for each circuit block 1 is a feature of the present invention. A plurality of four temperature detectors 2 provided adjacent to the respective circuit blocks 1 for detecting the signal and a detection mode switching signal input from a detection mode switching signal input terminal 5 are used to output the signals from the respective temperature detectors 2. A detection section switching circuit 3 for switching detection data to a detection data output terminal 4;

In the first embodiment, the detection mode switching signal input from the detection mode switching signal
By switching the detection data output from the temperature detector 2 adjacent to the plurality of four circuit blocks 1 included in the SI 20a, the junction temperature of each circuit block 1 can be detected.

The first embodiment is applied to a digital LSI, and the LSI is actually used, that is, mounted on a printed circuit board, input signals are input, and controlled by a detection mode switching signal. It is possible to detect the bonding temperature in an actual use state. The data obtained in this way enables an appropriate LSI design.

FIG. 2 is a circuit diagram showing a part of the circuit shown in FIG. A PN junction type diode 13 is used for the temperature detector 2 and each diode 13 is set to M
The switching is performed by the OS transistor 12, and one of the plurality of diodes 13 is connected to the detection data output terminal 4.

In this case, by supplying a constant current to the detection data output terminal 4 and measuring the voltage of the detection data output terminal 4, the junction temperature of each circuit block 1 can be calculated. In FIG. 2, reference numeral 14 denotes a GND terminal.

FIG. 3 is a block diagram showing a second embodiment of the present invention.

The LSI 20b of the second embodiment is characterized by a plurality of four temperature detectors 2 and a detection data comparison circuit 6 for comparing the data detected by the temperature detectors 2, which is a feature of the present invention.
And a detection section switching circuit 3 for switching the four detection data from the temperature detection section 2 based on the comparison result of the detection data comparison circuit 6 and outputting the data to the detection data output terminal 4.

In the second embodiment, the junction temperature of each circuit block 1 is detected, and the detection data of the temperature detector 2 adjacent to the circuit block 1 having the highest temperature is output to the detection data output terminal 4. The maximum output temperature of the LSI can be detected without external control.

FIG. 4 is a circuit diagram showing a part of the details of the circuit shown in FIG. Each diode 13
A constant current is applied by a constant current source 15 to each diode 1
The voltage at both ends of the diode 3 is compared by a voltage comparison circuit 16 to connect the diode 13 at the highest junction temperature to the detection data output terminal 4 by turning on the MOS transistor 12.

FIG. 5 is a block diagram showing a third embodiment of the present invention, showing a digital LSI composed of MOS transistors. In the third embodiment, in an LSI 20c having a plurality of two circuit blocks 1a, a plurality of two temperature detecting units 2 provided adjacent to each circuit block 1a, which is a feature of the present invention, are provided. A detection data comparison circuit 6 for comparing detection data from the detection unit 2 and outputting detection data of the temperature detection unit 2 adjacent to the circuit block 1 having the highest junction temperature to the voltage control circuit 8;
And V _T detecting section 7 for outputting a detection data of the threshold voltage V _T of the detected V _T to the voltage control circuit 5 of the transistor, a power supply unit 9 for supplying power to each circuit block 1, the detection data comparison circuit And a voltage control circuit 8 for controlling a power supply voltage to be supplied to the circuit block 1 of the power supply unit 9 based on data from the _VT detection unit 7 and data from the _VT detection unit 7.

Normally, in a digital LSI, when a certain operation is performed, as shown in FIG.
P-channel S transistors, the absolute value of V _T of each of the N-channel type | V _T | If decreases, although the power supply current I _DD tends to increase, the minimum operating voltage V _DD to the digital LSI operates, As shown in FIG. 8, there is a tendency to decrease. Based on these trends, the voltage control circuit 8, when the absolute value of V _T of the MOS transistor is small, set low power supply voltage supplied to the circuit block 1,
Means the absolute value of V _T is set to a high power supply voltage as the increased and, by the data from the detection data comparison circuit 6, so as not to exceed a certain temperature that the bonding temperature (usually 125 ° C), lowers the power supply voltage Have a means. By these means, to correct the variation of V _T of the MOS transistor caused in the manufacturing process, and the state in which LSI is actually used, i.e., mounted on a printed board, in a state that takes an input signal, the power consumption Because it can be controlled,
The maximum signal processing function can be mounted on the LSI.

FIG. 6 is a block diagram showing a fourth embodiment of the present invention, which shows a digital LSI composed of MOS transistors.

[0033] The present LSI20d fourth embodiment, in LSI20c the third embodiment of FIG. 5, it is an aspect of the present invention, with respect to V _T of the MOS transistor, the characteristics of the power supply voltage to be set, and A read-only memory (hereinafter, referred to as ROM) 11 is provided as a control storage unit that stores a control algorithm of a power supply voltage with respect to a junction temperature in advance.

In the fourth embodiment, the control characteristics slightly different for each LSI are built in the ROM 11, so that other blocks can be shared and the LSI design is facilitated. I have. Also, in some cases, after designing an actual LSI and performing trial production, it has the advantage that each characteristic can be calculated based on the result measured with an actual sample and built into the ROM. .

[0035]

As described above, the present invention provides an LSI
Is provided with a temperature detecting section, and an external control signal or L
Since there is a means for outputting detection data to a detection data output terminal by a decision circuit built in the SI,
It is possible to detect the junction temperature in a state where the device is actually used, and there is an effect that the maximum function can be built in the LSI.

Further, the present invention is applied to a digital LSI composed of MOS transistors,
Comprising a V _T detection circuit of the transistor, the maximum junction temperature and the V _T of the MOS transistors, to have a means for setting a proper voltage in a digital LSI, variations of V _T of the MOS transistor caused in the manufacturing process It is possible to control the power consumption in a state where the correction is performed and the LSI is actually used, and there is an effect that the maximum functions can be built in the LSI.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing part of the details.

FIG. 3 is a block diagram showing a second embodiment of the present invention.

FIG. 4 is a circuit diagram showing some of the details.

FIG. 5 is a block diagram showing a third embodiment of the present invention.

FIG. 6 is a block diagram showing a fourth embodiment of the present invention.

FIG. 7 is a block diagram showing a conventional example.

FIG. 8 is a minimum operating voltage characteristic diagram of the digital integrated circuit.

FIG. 9 is a _VT characteristic diagram of a power supply source flow versus a CMOS transistor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1, 1a Circuit block 2 Temperature detection part 3 Detection part switching circuit 4 Detection data output terminal 5 Detection mode switching signal input terminal 6 Detection data comparison circuit 7 _VT detection part 8 Voltage control circuit 9 Power supply part 10 Positive power supply terminal 11 ROM Reference Signs List 12 MOS transistor 13 Diode 14 GND terminal 15 Constant current source 16 Voltage comparison circuit 20, 20a, 20b, 20c, 20d Semiconductor integrated circuit (LSI)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-187254 (JP, A) JP-A-1-290249 (JP, A) JP-A-54-107688 (JP, A) JP-A-4- 209566 (JP, A) JP-A-5-121667 (JP, A) JP-A-5-36775 (JP, A) JP-A-62-179140 (JP, A) JP-A-2-23645 (JP, A) JP-A-2-28363 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 27/04 G01K 13/00 H01L 21/822

Claims (4)

(57) [Claims] 1. A semiconductor integrated circuit having an electronic circuit formed on one main surface of a semiconductor substrate, wherein the temperature detection is formed on one main surface of the semiconductor substrate and detects a temperature of the semiconductor substrate. comprising a part, the temperature detection unit is provided with a plurality, the detection mode switching signal inputted from the outside, a plurality
The detection data from the temperature detector is switched
A semiconductor integrated circuit comprising : a detection unit switching circuit that outputs to a data output terminal . 2. An electron formed on one main surface of a semiconductor substrate.
A semiconductor integrated circuit provided with a circuit, wherein the semiconductor substrate is formed on one main surface of the semiconductor substrate;
A temperature detection unit for detecting a temperature of the data, wherein a plurality of the temperature detection units are provided, and a detection data comparison unit selects detection data from the temperature detection unit adjacent to a circuit block having the highest temperature. A semiconductor integrated circuit comprising: a circuit; and a detection unit switching circuit that switches detection data from a plurality of the temperature detection units based on a comparison result of the detection data comparison circuit and outputs the detection data to a detection data output terminal. 3. An electron formed on one main surface of a semiconductor substrate.
A semiconductor integrated circuit provided with a circuit, wherein the semiconductor substrate is formed on one main surface of the semiconductor substrate;
A temperature detection unit for detecting the temperature of the semiconductor integrated circuit , the semiconductor integrated circuit is constituted by MOS transistors, and a plurality of the temperature detection units are provided, and the temperature detection unit is adjacent to a circuit block having the highest temperature. A detection data comparison circuit for selecting detection data from a unit; a threshold voltage detection unit for detecting a threshold voltage of the MOS transistor; and supplying power to a plurality of circuit blocks included in the semiconductor integrated circuit A power supply unit, and a voltage control circuit that controls a power supply voltage supplied from the power supply unit to the circuit block based on data from the detection data comparison circuit and data from the threshold voltage detection unit. A semiconductor integrated circuit characterized by the above. 4. The semiconductor integrated circuit according to claim 3 , further comprising a control data storage unit in which a control algorithm of said voltage control circuit is stored in advance.