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Integrator DC Amplifier for Type 2 Sample Data Phase Locked Oscillator

IP.com Disclosure Number: IPCOM000082541D
Original Publication Date: 1974-Dec-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Vaughn, JE: AUTHOR

Abstract

This phase-locked oscillator (PLO) circuit provides a constant reverse bias voltage across a diode 14, regardless of the voltage stored in an integrating capacitor 16. Thus, the time required to forward bias diode 14 is always the same, allowing the PLO circuit to be used for high frequency data rates.

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Integrator DC Amplifier for Type 2 Sample Data Phase Locked Oscillator

This phase-locked oscillator (PLO) circuit provides a constant reverse bias voltage across a diode 14, regardless of the voltage stored in an integrating capacitor 16. Thus, the time required to forward bias diode 14 is always the same, allowing the PLO circuit to be used for high frequency data rates.

The circuit operates so that the clamp voltage or the anode of diode 14 is referenced to the voltage stored in capacitor 16 through amplifier 18 and the clamp diode 12. Current switches CS1 and CS2 are normally in the condition illustrated in the figure, unless an error is generated, whereby one of the switches is required to change states. If an error occurs which requires current switch CS1 to switch, then current I(t) is drawn from ground, and currents I(p) and I(c) charge node 3 until diode 14 is forward biased and diode 12 is reverse biased. Then current I(p)charges capacitor 16 in a positive direction. The duration of the charge, and thus the amplitude of voltage depends upon the magnitude of the error. When the charge time is completed, current switch CS1 is switched back to its normal state, diode 14 is reverse biased, while diode 12 is forward biased, and the anode of diode 14 is clamped at the new voltage stored in capacitor 16.

If an error occurs which requires current switch CS2 to switch, then current is drawn out of capacitor 16 at an I(n) current rate, and the resultant voltage is...