Showing papers on "Bandgap voltage reference published in 1978"

A CMOS voltage reference

Abstract: A method for developing a reference voltage in CMOS integrated circuits is described. The circuit uses MOS devices operating in the weak inversion region, as well as a bipolar device formed without process modifications. A brief description of this region of operation is given. Then, the principle of the suggested voltage reference is explained and the final implementation is presented. Higher order effects are discussed, and results from an integrated prototype given.

A new NMOS temperature-stable voltage reference

Abstract: An NMOS voltage reference has been developed that exhibits extremely low drift with temperature. The reference is based on the difference between the gate/source voltages of enhancement and depletion-mode NMOS transistors. The theoretical dependence of the reference voltage on both device and circuit parameters is analyzed and conditions for optimal performance are derived. The reference NMOS transistors are biased to the optimizing current levels by a unique feedback circuit. The measured output voltage drift in the integrated realization agrees well with theory and is less than 5 parts per million per degree Celsius over the temperature range -55/spl deg/ to +125/spl deg/C.

A Low-Voltage CMOS Bandgap Reference

Abstract: The well-controlled exponential ID(VS) characteristics of MOS transistors operating in weak inversion allows the realization of a very good bandgap reference compatible with CMOS technologies and operating with an input voltage as low as 1.3 V. Variations of less than 3 mV over more than 100oC have been obtained on a few samples and are certainly within reach for each circuit with an adjustment. The temperature range can be further extended by improving the design.

Monolithic CMOS digital temperature measurement circuit

Abstract: A monolithic integrated complementary metal oxide semiconductor (CMOS) circuit senses internal junction temperature and converts it to a binary coded decimal output signal. The circuit compares a temperature dependent junction voltage with a bandgap reference voltage controlled by a very stable amplifier. The comparison differential is then converted to a binary coded decimal output signal by an analog to digital converter. The circuit utilizes parasitic bipolar NPN transistor elements formed from a substrate of the chip in a conventional CMOS fabrication process. The principles of the present invention are also broadly applicable to other semiconductor technologies such as integrated injection logic (I 2 L).

Temperature compensated bandgap IC voltage references

Abstract: Bandgap voltage reference circuits have been developed for integrated circuit applications. Typically, a negative temperature coefficient first voltage is developed related to the base to emitter potential of a transistor. A positive temperature coefficient second voltage related to the difference in base to emitter potential between two transistors operating at different current densities is developed and combined with the first voltage so as to produce a temperature compensated reference voltage. Such first order compensation leaves second order effects uncompensated. In the invention, a third voltage having a suitable temperature coefficient is combined with the first and second voltages so that the resultant reference voltage is compensated to a second order.

Temperature compensated bandgap voltage reference circuit

Abstract: A pair of transistors, connected as a differential amplifier, is operated so that the transistors run at different current densities. A voltage divider is coupled across a pair of circuit terminals so that a portion of the terminal voltage is coupled to and used to differentially bias the transistors. An amplifier, responsive to the transistors differential output, and coupled to the divider, is used to vary the terminal voltage to force the differential output to zero. The transistor bias voltage thus generated has a positive temperature coefficient of voltage. A forward biased diode, which has a negative temperature coefficient of voltage, is also incorporated into the divider. When the terminal voltage is made equal to the semiconductor bandgap, the two temperature sensitive terms cancel to compensate the reference voltage.

Selectively adjustable voltage detection integrated circuit

Abstract: A voltage detection integrated circuit including a voltage regulation circuit for controlling the operation thereof is provided. The voltage detection integrated circuit includes a reference voltage circuit for producing a predetermined reference voltage, a voltage converter for converting a detected voltage for measurement and a comparator circuit for comparing the level of the reference voltage to the level of the converted voltage and for producing a comparison signal representative of the difference in voltage levels compared thereby. The voltage regulation circuit is coupled to the comparator circuit and the reference voltage circuit and/or voltage conversion circuit for selectively adjusting the level of the reference voltage produced by the reference voltage circuit and/or the converted voltage produced by the voltage converter, to thereby control the comparison signal produced by the comparator circuit.

Driving circuit for integrated circuit semiconductor memory

Abstract: An improved driving circuit is provided especially for use in an integrated circuit semiconductor memory which operates on low power supply voltage, such as 5 volts, the drive circuit employing field effect transistors coupled with bootstrap capacitor devices and responsive to an input pulse for supplying, at its output terminal, a pulse having a peak voltage potential substantially equal to the power supply voltage value despite the inherent threshold voltage drops of the field effect transistors utilized. In the drive circuit, in response to an input pulse, the reference voltage for charged capacitor devices is switched between a first level and a raised second, higher level to place the capacitor devices in series with each other and the raised reference voltage to overdrive an output switch device so as to connect substantially its full power supply voltage to its output terminal during a corresponding output pulse.

FET Voltage level detecting circuit

Abstract: There is provided a voltage level detecting circuit useful as power-up/power-down voltage indicator for a field effect transistor integrated circuit. A constant voltage reference generator is provided by a depletion type transistor in series with two enhancement type transistors coupled between power supply terminals of the integrated circuit chip. Each of the enhancement type transistors have their gate electrodes connected to their drain electrodes while the depletion type transistor has its gate electrode connected to the more negative or reference terminal of the power supply voltage. A constant voltage output is taken from between the junction of one of the enhancement mode transistors and the depletion type transistor. This constant voltage output can be compared against a voltage obtained from a voltage divider circuit which provides an output that varies in accordance with variations in the power supply. The voltage level detector circuit is particularly useful in microprocessors and microcomputer integrated circuit chips.

Power circuit for different stabilized DC voltages

Abstract: In a power circuit arrangement, there are a plurality of voltage stabilizers each including a reference voltage source, a circuit for comparing the output of the respective voltage stabilizer with a reference voltage, and a voltage control element responsive to the output of the comparing circuit. The reference voltage for at least one of the voltage stabilizers is provided by an independent element, and the reference voltage for the remaining voltage stabilizers is formed on the basis of the output voltage of the other voltage stabilizers. When the output voltage of any one of the voltage stabilizers becomes zero, all of the other voltage stabilizers similarly have their output voltages reduced to zero.

Current limiting circuit for power packs - has part of output voltage compared with reference voltage depending on output current

Abstract: The power pack has current and voltage control and a differential amplifier comparing a part of the output voltage with a reference voltage and controlling the output current through a transistor in accordance with the result of this comparison. The reference voltage source (SQR) is controlled by the power pack output current (Ia), so that the value of the reference voltage (UF) applied to the differential amplifier (OV1) depends on the output current.

A Low-Voltage CMOS Bandgap Reference

Abstract: The well-controlled exponential ID(VS) characteristics of MOS transistors operating in weak inversion allows the realization of a very good bandgap reference compatible with CMOS technologies and operating with an input voltage as low as 1.3 V. Variations of less than 3 mV over more than 100oC have been obtained on a few samples and are certainly within reach for each circuit with an adjustment. The temperature range can be further extended by improving the design.

Temperature compensating type piezoelectric oscillator

Abstract: PURPOSE: To ensure an easy adjustment of the temperature compensation by combining the temperature dependent voltage generating circuit and the logic circuit featuring the gate function controlled by the output voltage of the above mentioned voltage generating circuit and then controlling the frequency of the oscillator circuit with use of the logic circuit. CONSTITUTION: The power source voltage +B is converted to the stable reference voltage through constant voltage diode 21 and then converted to the ambient temperature dependent voltage by resistance 22 and thermistor 23. This voltage is then divided by resistors 24, 25, 26 and 27 to be applied to NAND circuit 30 and 31. As the stable reference voltage is applied, the output of circuit 30 and 31 feature low levels in the case of the level of over the threshold voltage. With increment of the ambient temperature, the input voltage is converted to the stepped voltage of under the threshold voltage to be applied to one end of variable capacity diode 34, with the other end receiving application of the stable voltage. Thus, the frequency change caused by the temperature fluctuation of the voltage control voltage oscillator comprising piezoelectric oscillator and others can be compensated. The dispersion caused by the frequency temperature characteristics of the oscillator or the like can be controlled by variable resistor 36. COPYRIGHT: (C)1979,JPO&Japio