A Regulated Temperature-Insensitive High-Voltage Charge Pump in Standard CMOS Process for Micromachined Gyroscopes

Abstract

Micromachined gyroscopes require high voltage (HV) for actuation and detection to improve its precision, but the deviation of the HV caused by temperature fluctuations will degrade the sensor’s performance. In this paper, a high-voltage temperature-insensitive charge pump is proposed. Without adopting BCD (bipolar-CMOS-DMOS) technology, the output voltage can be boosted over the breakdown voltage of n-well/substrate diode using triple-well NMOS (n-type metal-oxide-semiconductor) transistors. By controlling the pumping clock’s amplitude continuously, closed-loop regulation is realized to reduce the output voltage’s sensitivity to temperature changes. Besides, the output level is programmable linearly in a large range by changing the reference voltage. The whole circuit has been fabricated in a 0.18- μ m standard CMOS (complementary metal-oxide-semiconductor) process with a total area of 2.53 mm 2 . Measurements indicate that its output voltage has a linear adjustable range from around 13 V to 16.95 V, and temperature tests show that the maximum variations of the output voltage at − 40 ∼ 80 ∘ C are less than 1.1%.

Keywords

• high-voltage generation
• regulated charge pump
• temperature-insensitive
• triple-well nmos transistor
• standard cmos process