Title :
A programmable positive and negative high-voltage DC-DC converter dedicated for ultrasonic applications
Author :
Chebli, R. ; Sawan, M. ; Savaria, Y.
Author_Institution :
Dept. of Electr. Eng., Ecole Polytechnique de Montreal, Que., Canada
Abstract :
This paper concerns the design and implementation of a fully integrated programmable high voltage CMOS DC-DC up-converter (PHVUC), followed by a negative high voltage doubler (NHVD) stage, which is dedicated to ultrasonic transmitters. The proposed PHVUC topology is based on a 5-stage charge pump circuit, and a level up shifter is used in each stage as a clock generator in order to increase exponentially the DC voltage. A floating gate technique is used to protect the gate oxide of transistors and a low power, low area level up shifter is proposed. Positive and negative HV DC levels are needed to drive ultrasound cells and are generated by a new NHVD. Post layout simulation results of the proposed circuits, using 0.8 μm CMOS/DMOS high-voltage process technology, show an output voltage range from -100V up to 200V and a fine programmability achieved with 98% gain voltage factor and 45mV output ripples at 2 MHz clock frequency. By implementing the floating gate technique, the power consumption of the level up shifter can be reduced to 50% compared to conventional one.
Keywords :
CMOS integrated circuits; DC-DC power convertors; power integrated circuits; transmitters; ultrasonic transmission; -100 to 200 V; 0.8 micron; 2 MHz; 45 mV; CMOS-DMOS high-voltage process; charge pump circuit; clock generator; floating gate; level up shifter; negative high voltage doubler; programmable high voltage CMOS DC-DC up-converter; ultrasonic transmitters; Acoustic applications; Charge pumps; Circuit topology; Clocks; DC generators; DC-DC power converters; Protection; Transmitters; Ultrasonic imaging; Voltage;
Conference_Titel :
Circuits and Systems, 2005. 48th Midwest Symposium on
Print_ISBN :
0-7803-9197-7
DOI :
10.1109/MWSCAS.2005.1594192