Title :
A 2.1-MHz crystal oscillator time base with a current consumption under 500 nA
Author :
Aebischer, Daniel ; Oguey, Henri J. ; Von Kaenel, Vincent R.
Author_Institution :
Centre Suisse d´´Electronique et de Microtechnique SA, Neuchatel, Switzerland
fDate :
7/1/1997 12:00:00 AM
Abstract :
A micropower crystal oscillator module for watch applications is presented. The integrated circuit is encapsulated with a 2.1-MHz crystal in a miniature vacuum package to reduce parasitic effects. The circuit comprises frequency tuning with a resolution of ±3 s/year [±0.1 parts per million (ppm)] and auxiliary circuits. A single output delivers a signal of 16 384 Hz with a frequency stability of ±2 ppm over the temperature range (-10 to 70°C). The oscillator core has two complementary active MOSFET´s and amplitude stabilization in order to get both low power consumption and high stability. New coupling and biasing circuits between the oscillator and the dynamic frequency dividers allow to achieve a current consumption under 0.5 μA for a supply voltage between 1.8 and 3.5 V
Keywords :
CMOS analogue integrated circuits; crystal oscillators; encapsulation; frequency dividers; time bases; -10 to 70 C; 1.8 to 3.5 V; 2.1 MHz; 500 nA; amplitude stabilization; biasing circuit; complementary active MOSFETs; coupling circuit; crystal oscillator time base; current consumption; dynamic frequency divider; encapsulated integrated circuit; frequency stability; frequency tuning; micropower module; parasitic effects; vacuum package; watch; Circuit optimization; Circuit stability; Coupling circuits; Energy consumption; Frequency; Integrated circuit packaging; Oscillators; Signal resolution; Temperature distribution; Watches;
Journal_Title :
Solid-State Circuits, IEEE Journal of
