A Fully Integrated Temperature-Independent Reconfigurable Acoustic Transmitter With Digital On-Chip Resistor Temperature Coefficient Calibration for Oil Drilling Application

Built upon our earlier works on high-temperature acoustic transmitters, a novel method to calibrate the resistor temperature coefficient compensation is proposed using a digital ΔΣ modulator. The resulting frequency reference generates a frequency of 1.4 MHz with an inaccuracy value of ±1.7% over the temperature range of 25°C-300°C. The acoustic transmitter generates both three-channel chirp and six-channel on-off keying modulation. Fabricated in a 1-μm silicon-on-insulator complementary metal-oxide-semiconductor, the chip occupies an area of 27.5 mm². Under 5-V supply, it can support up to 120 b/s while consuming 12 and 19 mW at 25°C and 300°C, respectively.