Honeywell International Inc.

Bradley A Kantor

James Douglas Seefeldt

Jeffrey James Kriz

A radiation-hardened charge pump circuit is provided. The circuit includes a first charge pump having a first charge pump output, a second charge pump having a second charge pump output, a first coincidence detector receiving as inputs the first charge pump output and the second charge pump output and producing as an output a first coincidence signal, and an analog 2:1 multiplexor for selecting either the first charge pump output or the second charge pump output based on the first coincidence signal. In alternative embodiment, the circuit includes at least three charge pumps, at least two coincidence detectors, decision logic, and a correspondingly-sized analog multiplexor.

Radiation-hardened charge pump topology

A radiation hard design for oscillator circuits and circuits having differential outputs is described. The design includes connecting or otherwise coupling outputs of these circuits to a passive polyphase filter. The passive polyphase filter provides four quadrature outputs that are free of glitches that may have occurred at the filter input.

Radiation hard oscillator and differential circuit design

An improved system and method for determining the lock condition of a Phase Locked Loop (PLL) is described. The lock detect circuit generates a fast lock detect signal that may be used to detect a transient loss of lock. The lock detect circuit may also include a phase alignment detect circuit to detect a misalignment in the phase of a reference clock and a feedback clock. Additionally, the lock detect circuit may include a reference clock detect circuit to detect if the reference clock signal is detected. Output signals from all of the above circuits may be communicated to a logic circuit in order to create an enhanced lock detect signal. An extended lock detect signal may also be communicated to the logic circuit.

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Plymouth, MN, United States of America

Bradley A Kantor