This paper presents a simple, low-cost temperature-to-digital-converter (TDC) with a wide operation range of -55 oC to 200 oC and inaccuracy of ±1.9 oC. The proposed method relies on device and layout matching to cancel the effects of component temperature coefficients and I-V characteristic nonlinearities and to enable accurate temperature sensing. Additionally, the proposed method decreases the design complexity and significantly improves area requirements and conversion speed of the TDC. Moreover, in the proposed design, no complicated signal processing devices, such as analog-to- digital converters (ADCs), are used, further decreasing the cost in terms of area and energy per conversion. The design is implemented in 65nm CMOS technology with a supply voltage of 2.5V. The total area of this TDC is 0.007 mm2 with an ultra- low energy per conversion of 9nJ.