Unitrode UC1635/UC2635/UC3635 Phase Locked Frequency Controller Datasheet

The UC1635 UC2635 UC3635 phase locked frequency controller is a precision phase locked frequency control system, which includes a crystal oscillator, programmable reference frequency dividers, a phase detector with absolute frequency steering, separate divider outputs and phase detector input pins, a frequency feedback sensing amplifier with double edge option, two high current op amps and 5V reference output. The series of integrated circuits are designed for use in precision speed control of DC motors. As an extension to the UC1633 line of phase locked controllers, these devices provide access to both of the digital phase detector’s inputs, and include a reference frequency divider output pin. With this added flexibility, this family of controllers can be used to obtain phase synchronization of multiple motors. A reference frequency can be generated using the device’s crystal oscillator and programmable dividers. The oscillator operates using a broad range of crystals, or, can function as a buffer stage to an external fre- quency source. The phase detector responds proportionally to the phase error between the detector’s minus input pin and the sense amplifier output. This phase detector includes absolute frequency steering to provide maxi- mum drive signals when any frequency error exists. This feature allows optimum start-up and lock times to be realized. Two op-amps are included that can be configured to provide necessary loop filtering. The outputs of these op-amps will source power for the phase detector.

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