• ETRI Journal
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• v.35 no.5
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• pp.797-807
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• 2013

In this paper, an input receiver with a hysteresis characteristic that can work at voltage levels between 0.9 V and 5 V is proposed. The input receiver can be used as a wide voltage range Schmitt trigger also. At the same time, reliable circuit operation is ensured. According to the research findings, this is the first time a wide voltage range Schmitt trigger is being reported. The proposed circuit is compared with previously reported input receivers, and it is shown that the circuit has better noise immunity. The proposed input receiver ends the need for a separate Schmitt trigger and input buffer. The frequency of operation is also higher than that of the previously reported receiver. The circuit is simulated using HSPICE at 0.35-${\mu}m$ standard thin oxide technology. Monte Carlo analysis is conducted at different process conditions, showing that the proposed circuit works well for different process conditions at different voltage levels of operation. A noise impulse of ($V_{CC}/2$) magnitude is added to the input voltage to show that the receiver receives the correct logic level even in the presence of noise. Here, $V_{CC}$ is the fixed voltage supply of 3.3 V.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.4
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• pp.42-50
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• 2003

This paper presents an embedded RC oscillator which has temperature compensation circuits. The conventional RC oscillator has frequency deviation about 15%, which is caused by variation of resistors and the reference voltage of schmitt trigger from the temperature condition. In this paper, the proposed circuit use a CMOS bandgap reference having balanced current temperature coefficients as a triggering voltage of schmitt trigger. The constant current sources consist of current mirror circuit with the positive and negative temperature coefficient. The proposed circuit shows less 3% frequency deviation for variation of temperature, supply voltage and process parameters.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.421-424
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• 2017

This paper describes a full-wave rectifiers for energy harvesting circuit using vibration detector. The designed circuit operates only when the vibration is detected through the vibration detector and the active diode. When there is no vibration, the comparator is turned off to prevent leakage of energy stored in the $C_{STO}$. The energy stored in the capacitor is used to drive the level converter and the active diode. The energy stored in the capacitor is supplied to an active diode designed as an output power. The vibration detector is implemented with Schmitt Trigger and Peak Detector with Hysteresis function. The proposed circuit is designed in a CMOS 0.35um technology and its functionality has been verified through extensive simulations. The designed chip occupies $590{\mu}m{\times}583{\mu}m$.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.5
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• pp.625-631
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• 2014

We propose a compact power-on reset circuit consisting of a switched capacitor, a capacitor, and a Schmitt trigger inverter. A switched capacitor working with a clock signal charges the capacitor. Thus, the voltage across the capacitor is increased toward the supply voltage. The circuit provides a reset pulse until the voltage across the capacitor reaches the high threshold voltage of the Schmitt trigger inverter. The proposed circuit is simple, compact, has no static power consumption, and works for a wide range of power-on rising times. Furthermore, the clock signal is available while the reset pulse is activated. The proposed circuit works for up to 6 s of power-on rising time, and occupies a $60{\times}30{\mu}m^2$ active area.

• Journal of IKEEE
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• v.21 no.4
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• pp.375-380
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• 2017

A differential current-to-time interval converter is presented for current mode sensors. It consists of a ramp voltage generator, a current mode sensor, a reference current source, two current-tunable Schmitt triggers, a one-shot multivibrator, and two logic gates. The design principle is to apply a ramp voltage to each input of the two current-tunable Schmitt triggers whose threshold voltages are proportional to the drain current values of the current mode sensors. A proposed circuit converts a current change in the ISFET biosensor into its equivalent pulse width change. A prototype circuit built using TSMC 0.18 nm CMOS process exhibit a conversion sensitivity amounting to $726.9{\mu}s/pH$ over pH variation range of 2-12 and a linearity error less than ${\pm}0.05%$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.7 s.361
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• pp.31-36
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• 2007

A saw-tooth waveform generator whose frequency can be controlled with a do bias current is proposed. The generator utilizes operational transconductance amplifiers (OTA's) as switching element. It features simple and wide sweep capability The circuit built with commercially avaliable components exhibits good linearity of current-to-frequency transfer characteristics and relatively low temperature sensitivity.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.6
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• pp.1301-1308
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• 2012

In this paper, the low-power clock generator synchronized with the AC power signal using the adiabatic dynamic CMOS logic (ADCL) buffer is proposed for adiabatic logics. To reduce the power dissipation in conventional CMOS logic and to maintain adiabatic charging and discharging with low power for the ADCL, the clock signal of logic circuits should be synchronized with the AC power source. The clock signal for an adiabatic charging and discharging with the AC power signal was generated with the designed Schmitt trigger circuit and ADCL frequency divider using the ADCL buffer. From the simulation result, the power consumption of the proposed clock generator was estimated with approximately 1.181uW and 37.42uW at output 3kHz and 10MHz respectively.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.11
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• pp.1274-1281
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• 1988

A new voltage-controlled oscillator based on a voltage-controlled integrator has been developed. It consists of a Schmitt-trigger and a voltage-controlled integrator, which is realized by an operational transconductance amplifier (OTA) and a grounded capacitor. The input control voltage changes the time constant of the integrator, and hence the oscillation frequency. The SPICE simulation shows that a prototype circuit, which oscillates at 12.21 KHz at 0 V, has the conversion sencitivity 2,437 Hz/V and the residual nonlinearity less than 0.68% in a control voltage range from -2 V to 2 V. It also shows that the circuit provides a temperature drift less than + 250 ppm/$^{\circ}$C for frequencies up to 100 KHz.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.35-38
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• 2018

This paper describes a low-power MPPT interface for DC-type energy harvesting sources. The proposed circuit consists of an MPPT controller, a bias generator, and a voltage detector. The MPPT controller consists of an MPG (MPPT Pulse Generator) with a schmitt trigger, a logic gate operating according to energy type (light, heat), and a sample/hold circuit. The bias generator is designed by employing a beta multiplier structure, and the voltage detector is implemented using a bulk-driven comparator and a two-stage buffer. The proposed circuit is designed with $0.35{\mu}m$ CMOS process. The simulation results show that the designed circuit consumes less than 100nA of current at an input voltage of less than 3V and the maximum power efficiency is 99.7%. The chip area of the designed circuit is $1151{\mu}m{\times}940{\mu}m$.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.10
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• pp.20-37
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• 1996

A current-controlled OTA-R schemitt trigger circuit is described. It consists of two OTA's and two resistors. The output level of the circuit is determined by one OTA and one resistor, and the threshold level by the other OtA and resistor. The theory of operation is presented and computer simulation results and experimental results using CMOS arrays are used to verify theoretical predictions. The results show close agreement between predicted behaviour and experimental performance.