Infrared Thermal Monitoring of Intelligent Grassland via Drone

This paper presents a power-oriented monitoring of clock signals that is designed to avoid synchronization failure in computer systems such as FPGAs. The proposed design reduces power consumption and increases the power-oriented checkability in FPGA systems. These advantages are due to improvements in the evaluation and measurement of corresponding energy parameters. Energy parameter orientation has proved to be a good solution for detecting a synchronization failure that blocks logic monitoring circuits. Key advantages lay in the possibility to detect a synchronization failure hidden in safety-related systems by using traditional online testing that is based on logical checkability. Two main types of power-oriented monitoring are considered: detecting a synchronization failure based on the consumption and the dissipation of power, which uses temperature and current consumption sensors, respectively. The experiments are performed on real FPGA systems with the controlled synchronization disconnection and the use of the computer-aided design (CAD) utility to estimate the decreasing values of the energy parameters. The results demonstrate the limited checkability of FPGA systems when using the thermal monitoring of clock signals and success in monitoring by the consumption current.

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A High-Speed Temperature Sensor with Low Supply Sensitivity for SoC Thermal Monitoring

Journal of Circuits System and Computers ◽

10.1142/s0218126618501165 ◽

2018 ◽

Vol 27 (07) ◽

pp. 1850116

Author(s):

Yuanxin Bao ◽

Wenyuan Li

Keyword(s):

Temperature Sensor ◽

Conversion Rate ◽

High Speed ◽

Supply Voltage ◽

Ring Oscillator ◽

Temperature Sensitive ◽

Cmos Process ◽

Digital Code ◽

Thermal Monitoring ◽

Worst Case

A high-speed low-supply-sensitivity temperature sensor is presented for thermal monitoring of system on a chip (SoC). The proposed sensor transforms the temperature to complementary to absolute temperature (CTAT) frequency and then into digital code. A CTAT voltage reference supplies a temperature-sensitive ring oscillator, which enhances temperature sensitivity and conversion rate. To reduce the supply sensitivity, an operational amplifier with a unity gain for power supply is proposed. A frequency-to-digital converter with piecewise linear fitting is used to convert the frequency into the digital code corresponding to temperature and correct nonlinearity. These additional characteristics are distinct from the conventional oscillator-based temperature sensors. The sensor is fabricated in a 180[Formula: see text]nm CMOS process and occupies a small area of 0.048[Formula: see text]mm2 excluding bondpads. After a one-point calibration, the sensor achieves an inaccuracy of [Formula: see text][Formula: see text]1.5[Formula: see text]C from [Formula: see text]45[Formula: see text]C to 85[Formula: see text]C under a supply voltage of 1.4–2.4[Formula: see text]V showing a worst-case supply sensitivity of 0.5[Formula: see text]C/V. The sensor maintains a high conversion rate of 45[Formula: see text]KS/s with a fine resolution of 0.25[Formula: see text]C/LSB, which is suitable for SoC thermal monitoring. Under a supply voltage of 1.8[Formula: see text]V, the maximum energy consumption per conversion is only 7.8[Formula: see text]nJ at [Formula: see text]45[Formula: see text]C.

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