# Sining Pan

## Publications

**A 6.6-μW Wheatstone-Bridge Temperature Sensor for Biomedical Applications**

S. Pan; K. A. A. Makinwa;*IEEE Solid-State Circuits Letters*,

Volume 3, pp. 334-337, 2020. DOI: 10.1109/LSSC.2020.3019078

## Abstract: ...

This letter presents a compact, energy-efficient, and low-power Wheatstone-bridge temperature sensor for biomedical applications. To maximize sensitivity and reduce power dissipation, the sensor employs a high-resistance (600 kΩ) bridge that consists of resistors with positive (silicided-poly) and negative (n-poly) temperature coefficients. Resistor spread is then mitigated by trimming the n -poly arms with a 12-bit DAC, which consists of a 5-bit series DAC whose LSB is trimmed by a 7-bit PWM generator. The bridge is readout by a second-order delta–sigma modulator, which dynamically balances the bridge by tuning the resistance of the silicided-poly arms via a 1-bit series DAC. As a result, the modulator’s bitstream average is an accurate and near-linear function of temperature, which does not require further correction in the digital domain. Fabricated in a 180-nm CMOS technology, the sensor occupies 0.12mm2 . After a 1-point trim, it achieves +0.2 °C/−0.1 °C (3σ) inaccuracy in a ±10 °C range around body temperature (37.5 °C). It consumes 6.6 μW from a 1.6-V supply, and achieves 200-μK resolution in a 40-ms conversion time, which corresponds to a state-of-the-art resolution FoM of 11 fJ⋅K2 . Duty cycling the sensor results in even lower average power: 700nW at 10 conversions/s.**A 10 fJ·K² Wheatstone Bridge Temperature Sensor With a Tail-Resistor-Linearized OTA**

S. Pan; K. A. A. Makinwa;*IEEE Journal of Solid-State Circuits*,

2020. DOI: 10.1109/JSSC.2020.3018164

## Abstract: ...

This article describes a highly energy-efficient Wheatstone bridge temperature sensor. To maximize sensitivity, the bridge is made from resistors with positive (silicided diffusion) and negative (poly) temperature coefficients. The bridge is balanced by a resistive (poly) FIR-DAC, which is part of a 2nd-order continuous-time delta-sigma modulator (CTΔ ΣM). Each stage of the modulator is based on an energy-efficient current-reuse OTA. To efficiently suppress quantization noise foldback, the 1st stage OTA employs a tail-resistor linearization scheme. Sensor accuracy is enhanced by realizing the poly arms of the bridge and the DAC from identical unit elements. Fabricated in a 180-nm CMOS technology, the sensor draws 55 μW from a 1.8-V supply and achieves a resolution of 150 μK_rms in an 8-ms conversion time. This translates into a state-of-the-art resolution figure-of-merit (FoM) of 10 fJ·K². Furthermore, the sensor achieves an inaccuracy of ±0.4 °C (3σ) from -55 °C to 125 °C after a ratio-based one-point trim and systematic non-linearity removal, which improves to ±0.1 °C (3σ) after a 1st-order fit.**A CMOS Resistor-Based Temperature Sensor with a 10fJ· K2 Resolution FoM and 0.4° C (3σ) Inaccuracy From− 55°C to 125°C After a 1-point Trim**

S. Pan; K.A.A Makinwa;

In*Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC)*,

pp. 68-70, 2 2020. DOI: 10.1109/ISSCC19947.2020.9063064**A 16MHz CMOS RC Frequency Reference with±400ppm Inaccuracy from− 45° C to 85° C After Digital Linear Temperature Compensation**

Ç. Gürleyük; S. Pan; K.A.A Makinwa;

In*Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC)*,

pp. 64-66, 2 2020. DOI: 10.1109/ISSCC19947.2020.9063029**A 0.12mm2 Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C**

S. Pan; Ç. Gürleyük; M.F. Pimenta; K.A.A Makinwa;

In*Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC)*,

2 2019. DOI: 10.1109/ISSCC.2019.8662457**A Wheatstone-Bridge Temperature Sensor with a Resolution FoM of 20fJ·K2**

S. Pan; K.A.A Makinwa;

In*Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC)*,

2 2019. DOI: 10.1109/ISSCC.2019.8662337**A Resistor-Based Temperature Sensor with a 0.13pJ·K2 Resolution FOM**

S. Pan; Y. Luo; S.H. Shalmany; K.A.A. Makinwa;*IEEE Journal of Solid-State Circuits*,

Volume 53, Issue 1, pp. 164-173, 1 2018. DOI: 10.1109/JSSC.2017.2746671

## Abstract: ...

This paper describes a high-resolution energy-efficient CMOS temperature sensor, intended for the temperature compensation of MEMS/quartz frequency references. The sensor is based on silicided poly-silicon thermistors, which are embedded in a Wien-bridge RC filter. When driven at a fixed frequency, the filter exhibits a temperature-dependent phase shift, which is digitized by an energy-efficient continuous-time phase-domain delta-sigma modulator. Implemented in a 0.18-μm CMOS technology, the sensor draws 87 μA from a 1.8 V supply and achieves a resolution of 410 μKrms in a 5-ms conversion time. This translates into a state-of-the-art resolution figure-of-merit of 0.13 pJ·K². When packaged in ceramic, the sensor achieves an inaccuracy of 0.2 °C (3σ) from -40 °C to 85 °C after a single-point calibration and a correction for systematic nonlinearity. This can be reduced to ±0.03 °C (3σ) after a first-order fit. In addition, the sensor exhibits low 1/f noise and packaging shift.**A 0.25 mm2-Resistor-Based Temperature Sensor With an Inaccuracy of 0.12 °C (3σ) From −55 °C to 125 °C**

S. Pan; K. A. A. Makinwa;*IEEE Journal of Solid-State Circuits*,

Volume 53, Issue 12, pp. 3347-3355, 12 2018. DOI: 10.1109/JSSC.2018.2869595

## Abstract: ...

This paper describes a compact, energy efficient, resistor-based temperature sensor that can operate over a wide temperature range (-55 °C-125 °C). The sensor is based on a Wheatstone bridge (WhB) made from silicided poly-silicon and non-silicided poly-silicon resistors. To achieve both area and energy efficiencies, the current output of the WhB is digitized by a continuous-time zoom analog-to-digital converter (ADC). Implemented in a standard 180-nm CMOS technology, the sensor consumes 52 μA from a 1.8-V supply and achieves a resolution of 280 μKrms in a 5-ms conversion time. This corresponds to a state-of-the-art resolution figure-of-merit (FoM) of 40 fJ · K². After a first-order fit, the sensor achieves an inaccuracy of ±,0.12 °C (3σ) from -55 °C to 125 °C.**A CMOS Dual-RC Frequency Reference with ±200-ppm Inaccuracy from −45 °C to 85 °C**

Ç. Gürleyük; L. Pedalà; S. Pan; F. Sebastiano; K. A. A. Makinwa;*IEEE Journal of Solid-State Circuits*,

Volume 53, Issue 12, pp. 3386-3395, 12 2018. DOI: 10.1109/JSSC.2018.2869083

## Abstract: ...

This paper presents a 7-MHz CMOS RC frequency reference. It consists of a frequency-locked loop in which the output frequency of a digitally controlled oscillator (DCO) is locked to the combined phase shifts of two independent RC (Wien bridge) filters, each employing resistors with complementary temperature coefficients. The filters are driven by the DCO’s output frequency and the resulting phase shifts are digitized by high-resolution phase-to-digital converters. Their outputs are then combined in the digital domain to realize a temperature-independent frequency error signal. This digitally assisted temperature compensation scheme achieves an inaccuracy of ±200 ppm from –45 °C to 85 °C after a two-point trim. The frequency reference draws 430 μA from a 1.8-V supply, while achieving a supply sensitivity of 0.18%/V and a 330-ppb Allan deviation floor in 3 s of measurement time.**A 0.25mm2 resistor-based temperature sensor with an inaccuracy of 0.12°C (3σ) from −55°C to 125°C and a resolution FOM of 32fJK2**

S. Pan; K.A.A. Makinwa;

In*Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC)*,

pp. 320 - 322, 2 2018. DOI: 10.1109/ISSCC.2018.8310313**Energy-Efficient High-Resolution Resistor-Based Temperature Sensors**

S. Pan; K.A.A. Makinwa;

Springer, Chapter Hybrid ADCs, Sm, , 2017.**Optimum Synchronous Phase Detection and its Application in Smart Sensor Interfaces**

S. Pan; K.A.A. Makinwa;

In*IEEE International Symposium on Circuits and Systems (ISCAS)*,

June 2017. DOI: 10.1109/iscas.2017.8050417**Energy-Efficient High-Resolution Resistor-Based Temperature Sensors**

S. Pan; K.A.A. Makinwa;

In*Proc. Advances in Analog Circuit Design Workshop (AACD)*,

April 2017. DOI: 10.1007/978-3-319-61285-0_10**A Frequency-Locked Loop Based on an Oxide Electrothermal Filter in Standard CMOS**

L. Pedala; C. Gurleyuk; S. Pan; F. Sebastiano; K. Makinwa;

In*European Solid-State Circuits Conference (ESSCIRC)*,

Leuven, Belgium, 9 2017. DOI: 10.1109/esscirc.2017.8094512**A CMOS Temperature Sensor with a 49fJ·K2 Resolution FoM**

S. Pan; H. Jiang; K.A.A. Makinwa;

In*Dig. Techn. Paper IEEE Symposium on VLSI Circuits (VLSI)*,

6 2017. DOI: 10.23919/vlsic.2017.8008557**A Resistor-Based Temperature Sensor with a 0.13pJ·K2 Resolution FOM**

S. Pan; Y. Luo; S.H. Shalmany; K.A.A. Makinwa;

In*IEEE International Solid-State Circuits Conference (ISSCC)*,

February 2017. DOI: 10.1109/jssc.2017.2746671**A high-resolution resistor-based temperature sensor**

S. Pan;

MSc thesis, Delft University of Technology, Aug 2016. cum laude.