<p>This article proposes a fully digital temperature sensor with ultra-small sensing front-end for on-chip thermal management. Utilizing the temperature characteristics of MOSFET leakage current, an innovative Leakage-Dominated inverting Schmitt-Trigger (LDST) is proposed. The ring oscillator composed of LDST achieves temperature-to-frequency conversion. Different from the traditional fixed resolution and conversion time within the full temperature range, Adaptive Resolution Frequency-to-Digital Converter (AR-FDC) is proposed to realize faster measurement speed at high temperatures to timely prevent chip overheating while maintaining high resolution at low temperatures. Fabricated with a 55 nm CMOS process, the front-end of proposed temperature sensor occupies a silicon area of just 187 <InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10470_2025_2321_Article_IEq3.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="32" /> </InlineMediaObject> <EquationSource Format="TEX">$\mu \text {m}^2$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>μ</mi> <msup> <mtext>m</mtext> <mn>2</mn> </msup> </mrow> </math></EquationSource> </InlineEquation>. The temperature sensor achieves a resolution Figure of Merit (FoM) of 208 <InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10470_2025_2321_Article_IEq4.gif" Format="GIF" Height="20" Rendition="HTML" Resolution="72" Type="Linedraw" Width="50" /> </InlineMediaObject> <EquationSource Format="TEX">$\text {pJ}\cdot \text {K}^{2}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mtext>pJ</mtext> <mo>·</mo> <msup> <mtext>K</mtext> <mn>2</mn> </msup> </mrow> </math></EquationSource> </InlineEquation>, the power consumption of 7.2 <InlineEquation ID="IEq5"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10470_2025_2321_Article_IEq5.gif" Format="GIF" Height="17" Rendition="HTML" Resolution="72" Type="Linedraw" Width="29" /> </InlineMediaObject> <EquationSource Format="TEX">$\mu \text {W}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>μ</mi> <mtext>W</mtext> </mrow> </math></EquationSource> </InlineEquation>, the resolution of 112 mK, the conversion time of 1.66 ms at 20<InlineEquation ID="IEq6"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10470_2025_2321_Article_IEq6.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="25" /> </InlineMediaObject> <EquationSource Format="TEX">$^\circ \hbox { C}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mmultiscripts> <mrow /> <mrow /> <mo>∘</mo> </mmultiscripts> <mspace width="0.333333em" /> <mtext>C</mtext> </mrow> </math></EquationSource> </InlineEquation>, the max-min inaccuracy of <InlineEquation ID="IEq7"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10470_2025_2321_Article_IEq7.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="124" /> </InlineMediaObject> <EquationSource Format="TEX">$+0.48/-0.46^\circ \hbox { C}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo>+</mo> <mn>0.48</mn> <mo stretchy="false">/</mo> <mo>-</mo> <mn>0</mn> <mo>.</mo> <msup> <mn>46</mn> <mo>∘</mo> </msup> <mspace width="0.333333em" /> <mtext>C</mtext> </mrow> </math></EquationSource> </InlineEquation> and 3<InlineEquation ID="IEq8"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10470_2025_2321_Article_IEq8.gif" Format="GIF" Height="10" Rendition="HTML" Resolution="72" Type="Linedraw" Width="13" /> </InlineMediaObject> <EquationSource Format="TEX">$\sigma$</EquationSource> <EquationSource Format="MATHML"><math> <mi>σ</mi> </math></EquationSource> </InlineEquation>-inaccuracy of ±0.73<InlineEquation ID="IEq9"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10470_2025_2321_Article_IEq9.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="25" /> </InlineMediaObject> <EquationSource Format="TEX">$^\circ \hbox { C}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mmultiscripts> <mrow /> <mrow /> <mo>∘</mo> </mmultiscripts> <mspace width="0.333333em" /> <mtext>C</mtext> </mrow> </math></EquationSource> </InlineEquation> from <InlineEquation ID="IEq10"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10470_2025_2321_Article_IEq10.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="32" /> </InlineMediaObject> <EquationSource Format="TEX">$-10$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo>-</mo> <mn>10</mn> </mrow> </math></EquationSource> </InlineEquation> to 120<InlineEquation ID="IEq11"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10470_2025_2321_Article_IEq11.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="25" /> </InlineMediaObject> <EquationSource Format="TEX">$^\circ \hbox { C}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mmultiscripts> <mrow /> <mrow /> <mo>∘</mo> </mmultiscripts> <mspace width="0.333333em" /> <mtext>C</mtext> </mrow> </math></EquationSource> </InlineEquation> after two-point calibration. It can operate under a supply voltage ranging from 0.8 to 1.3 V, with a supply sensitivity of 3.02 <InlineEquation ID="IEq12"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10470_2025_2321_Article_IEq12.gif" Format="GIF" Height="6" Rendition="HTML" Resolution="72" Type="Linedraw" Width="17" /> </InlineMediaObject> <EquationSource Format="TEX">$\sim$</EquationSource> <EquationSource Format="MATHML"><math> <mo>∼</mo> </math></EquationSource> </InlineEquation> 4.51<InlineEquation ID="IEq13"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10470_2025_2321_Article_IEq13.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="25" /> </InlineMediaObject> <EquationSource Format="TEX">$^\circ \hbox { C}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mmultiscripts> <mrow /> <mrow /> <mo>∘</mo> </mmultiscripts> <mspace width="0.333333em" /> <mtext>C</mtext> </mrow> </math></EquationSource> </InlineEquation>/V.</p>

A fully digital temperature sensor with 187-$\mu \text {m}^{2}$ front-end for on-chip thermal management in 55-nm CMOS

期刊论文
发表日期：

2025年1月27日

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Zhao Yang,
Hao Li,
Peiyong Zhang

摘要

This article proposes a fully digital temperature sensor with ultra-small sensing front-end for on-chip thermal management. Utilizing the temperature characteristics of MOSFET leakage current, an innovative Leakage-Dominated inverting Schmitt-Trigger (LDST) is proposed. The ring oscillator composed of LDST achieves temperature-to-frequency conversion. Different from the traditional fixed resolution and conversion time within the full temperature range, Adaptive Resolution Frequency-to-Digital Converter (AR-FDC) is proposed to realize faster measurement speed at high temperatures to timely prevent chip overheating while maintaining high resolution at low temperatures. Fabricated with a 55 nm CMOS process, the front-end of proposed temperature sensor occupies a silicon area of just 187 $\mu \text {m}^2$ $μ m^{2}$ . The temperature sensor achieves a resolution Figure of Merit (FoM) of 208 $\text {pJ}\cdot \text {K}^{2}$ $pJ \cdot K^{2}$ , the power consumption of 7.2 $\mu \text {W}$ $μ W$ , the resolution of 112 mK, the conversion time of 1.66 ms at 20 $^\circ \hbox { C}$ $^{\circ} C$ , the max-min inaccuracy of $+0.48/-0.46^\circ \hbox { C}$ $+ 0.48 / - 0 . 46^{\circ} C$ and 3 $\sigma$ $σ$ -inaccuracy of ±0.73 $^\circ \hbox { C}$ $^{\circ} C$ from $-10$ $- 10$ to 120 $^\circ \hbox { C}$ $^{\circ} C$ after two-point calibration. It can operate under a supply voltage ranging from 0.8 to 1.3 V, with a supply sensitivity of 3.02 $\sim$ $\sim$ 4.51 $^\circ \hbox { C}$ $^{\circ} C$ /V.

A fully digital temperature sensor with 187-\(\mu \text {m}^{2}\) front-end for on-chip thermal management in 55-nm CMOS

摘要