Open Access1V relaxation oscillator with integrated voltage and current reference
Author(s) -
Wang Lidan,
Zhan Chenchang
Publication year - 2020
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2020.1855
Subject(s) - voltage reference , relaxation oscillator , voltage , resistor , temperature coefficient , electrical engineering , cmos , capacitor , materials science , bandgap voltage reference , current (fluid) , physics , optoelectronics , voltage controlled oscillator , engineering , dropout voltage
This Letter presents a novel relaxation oscillator with integrated voltage and current reference circuit, which generates a 32 kHz clock reference with 1% accuracy and has total power consumption of 122 nW at 1 V. Its temperature coefficient (TC) is 104 ppm/°C with a temperature range of −40 to 100°C, and its supply voltage accuracy is 1.6%/V from 1 to 1.8 V. The proposed oscillator uses the voltage reference directly to compare with the charging capacitor voltage, and the charging current is derived from the voltage reference divided by one temperature‐independent resistor. The advantages are that the accuracy of output frequency and TC can be trimmed simultaneously and independently. It is fabricated in 0.18 μm CMOS technology and occupies 0.059 mm 2 including the voltage and current reference circuits.