  High linear voltage references circuitry are designed and implemented in TSMC
0.18$\mu$m CMOS technology. Previous research has proposed the use of MOS
transistors operating in the weak inversion region to replace the bipolar
devices in conventional PTAT(proportional to absolute temperature) circuits.
However such solutions often have linearity problem in high temperature region
due to the current leaking devices in modern deep sub micron and nano-scale
CMOS technology. The proposed circuit utilized temperature complementation
technique on two voltage references, PTAT and IOAT (independent of absolute
temperature) references, to enhance the linearity and produce a more stable
IOAT voltage reference. Base on the simulation results, the R-squares of both
circuitries are better than 0.999 in a considerable wider temperature range
from -55 degrees C to 170 degrees C. Thus, a fully integrated temperature
sensor with wider temperature range is designed and easily to integrate to
modern system-on-chip designs with minimal efforts.
