Sand 9, Inc.

Analog Devices,inc.

Mohammad Asmani

Klaus Juergen Schoepf

Reimund Rebel

Dean A Badillo

Bruce Michael Newman

Peiqing Zhu

Circuits for charging capacitors in connection with oscillators are described. The oscillator may include a mechanical resonator. The circuits may include a charging element and a switched capacitor subcircuit to control operation of the charging element, and may be considered a charging circuit in some scenarios. The charging circuits may provide rapid charging of a capacitor to provide a reference voltage to the oscillator.

Circuits and methods for capacitor charging

The disclosed power-on reset circuit provides an indication of when and whether a supply voltage Vdd has reached a trigger voltage level Vtrig. The disclosed circuit includes a flip-flop circuit and a first comparator circuit. The circuit according to the invention has a D input node of the flip-flop circuit coupled to the supply voltage. The first comparator circuit outputs a clock signal, where the flip-flop circuit is clocked by the clock signal. A Q output node of the flip-flop circuit provides the power-on reset signal, where the power-on reset signal is in a LO state when the supply voltage is at a voltage level that is less than the trigger voltage level Vtrig. The power-on reset signal is in a HI state when the supply voltage is at a voltage level that is greater than the trigger voltage level Vtrig.

Power on reset circuit and method of use

Power-on reset circuit and method

Growing community of inventors

Ladera Ranch, CA, United States of America

Mohammad Asmani