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 Delta Sigma 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 degrees C-300 degrees C. The acoustic transmitter generates both three-channel chirp and six-channel on-off keying modulation. Fabricated in a 1-mu m silicon-on-insulator complementary metal-oxide-semiconductor, the chip occupies an area of 27.5 mm(2). Under 5-V supply, it can support up to 120 b/s while consuming 12 and 19 mWat 25 degrees C and 300 degrees C, respectively.