This　paper　proposes　a　low-power　delta-sigma　capacitance-To-digital　converter　(CDC)　for　a　capacitive　sensor.　The　input　of　the　capacitive　sensor　employs　a　zoomed-in　technique　with　the　offset　capacitor　to　extend　the　input　capacitance　range.　The　proposed　CDC　uses　a　third-order　switched　capacitor　delta-sigma　modulator　to　provide　a　digital　output,　based　on　a　cascade　of　integrators　with　a　feed　forward　(CIFF)　structure.　The　current-starved　operational　transconductance　amplifiers　(OTAs)　are　applied　in　the　delta-sigma　modulator＇s　first　integrator　to　improve　the　current　efficiency　and　reduce　the　power　consumption.　An　auto-zeroing　technique　is　used　in　the　OTAs　to　reduce　their　offset　and　noise.　The　circuit　was　implemented　in　a　0.18-\mu　\text{m}　CMOS　technology　and　occupies　an　area　of　0.496　mm2.　The　measurable　capacitance　range　of　the　CDC　can　be　varied　from　0　to　8　pF.　In　a　measurement　time　of　0.8　ms,　the　delta-sigma　CDC　achieved　a　12.7　effective　number　of　bits　while　consuming　18.6-\mu　\text{A}　current　from　a　2-V　supply　voltage.　©　2013　IEEE.