PTAT Current Research Articles

Low-power current reference with temperature compensation by subthreshold leakage current

A compact and power-efficient current reference with curvature-correction temperature characteristics is presented. Introducing of PTAT current into the loop of CTAT current generator results in reduced TC of VGS, which makes the aspect ratios of MOSFETs decrease when perform the first-order temperature compensation. Application of the subthreshold leakage current with curvature temperature feature to the reference current improves the temperature stability of output current to 52.1 ​ppm/°C over temperature range of −30 to 120 ​°C. This reference implemented in a 180 ​nm process with core area of 0.08 ​mm2 can work in a wide voltage range from 1.0 ​V to 2.4 ​V and consume current about 1 ​μA ​at 1.2 ​V.

A 24.4 ppm/°C Voltage Mode Bandgap Reference With a 1.05V Supply

This brief proposes a sub-1V, voltage mode CMOS bandgap reference circuit. Conventionally, sub-1V references are obtained by converting PTAT and CTAT voltages to currents and summing them in the current domain. Such techniques have multiple operating points and cannot natively support applications that require PTAT currents in addition to a bandgap voltage. This brief presents a voltage mode reference circuit, which adds a PTAT voltage with a scaled version of a CTAT voltage all within the sub-1V domain. Compared to current mode bandgaps, summing in voltage domain enables reduction of one CTAT current mirror stage and a significant reduction in PTAT current mirror ratio resulting in a reduced number of error sources. In addition, this circuit also natively supports applications that require PTAT current. A novel, high-accuracy self-biasing technique has been adopted to minimize the systematic offset induced temperature coefficient. A prototype designed in 45nm TSMC CMOS technology for a nominal voltage of 500mV demonstrates 24.4ppm/°C temperature coefficient from -40°C to 125°C, 0.15% line regulation, and draws 7.2μ\textA from a 1.05V supply.

A 139 nW, 67 $$\hbox {ppm}/^\circ \hbox {C}$$ ppm / ∘ C BJT-CMOS-Based Voltage Reference Circuit

In this work, a low-power voltage reference circuit has been developed using the principle that a thermal compensation of the threshold voltage of a diode-connected nMOSFET can be obtained by using the PTAT current. The proposed circuit is designed using \(0.18\,\upmu \hbox {m}\) standard CMOS technology for the industrial temperature range of \(-40\) to \(+85\,^\circ \hbox {C}\). The measurements have been done over a set of 10 samples in the given temperature range. The measured results show that the proposed circuit is capable of working in the supply voltage range of 1.2–1.8 V with the mean line sensitivity and total current consumption of 0.64%/V and \(115.4\,\hbox {nA}\), respectively, at \(22.5\,^\circ \hbox {C}\). The measured mean reference voltage obtained from the circuit is 435 mV with the mean temperature coefficient of \(67\,\hbox {ppm}{/}^\circ \hbox {C}\) . The measured noise density at \(22.5\,^\circ \hbox {C}\) without any filtering capacitor is \(42\,\upmu \hbox {V}{/}\sqrt{\text {Hz}}\) at 100 Hz. The active area of the circuit is \(0.01008\,\hbox {mm}^2\).

Design of an Embedded CMOS Temperature Sensor for Passive RFID Tag Chips.

This paper presents an ultra-low embedded power temperature sensor for passive RFID tags. The temperature sensor converts the temperature variation to a PTAT current, which is then transformed into a temperature-controlled frequency. A phase locked loop (PLL)-based sensor interface is employed to directly convert this temperature-controlled frequency into a corresponding digital output without an external reference clock. The fabricated sensor occupies an area of 0.021 mm2 using the TSMC 0.18 1P6M mixed-signal CMOS process. Measurement results of the embedded sensor within the tag system shows a 92 nW power dissipation under 1.0 V supply voltage at room temperature, with a sensing resolution of 0.15 °C/LSB and a sensing accuracy of −0.7/0.6 °C from −30 °C to 70 °C after 1-point calibration at 30 °C.

개선된 CTAT 보상을 가지는 저전압 CMOS Bandgap Voltage Reference

In this paper, a modified low-votlage CMOS bandgap voltage reference with CTAT compensation is presented. The proposed structure doesn"t use PTAT current. The proposed structure is more simple than the existing structure and doesn"t use the eighteen BJT. The modified low-votlage CMOS bandgap voltage reference with CTAT compensation has been successfully verified in a standard 0.18um CMOS process. The simulation results have confirmed that, with the minimum supply voltage of 1.25V, the output reference voltage at 549mV has a temperature coefficient of 12ppm/°C from 0°C to 100°C.

サブスレッショルドＭＯＳＦＥＴを用いたＰＴＡＴ電流生成のための微小フローティング電圧源回路

A floating millivolt reference circuit to generate a PTAT current was developed by using MOSFETs operated in the subthreshold region. The circuit generates a floating voltage of 10 mV. The variations in the reference are ±2.7 % in a temperature range from -20 to 100°C. The total power consumption of the circuit was 1.3 μW.