UC3634

UC1634 UC2634 UC3634 Phase Locked Frequency Controller FEATURES Precision Phase Locked Frequency Control System Communication Logic for 2-Phase Motors Disable Input for Motor Inhibit Crystal Oscillator Programmable Reference Frequency Dividers Phase Detector with Absolute Frequency Steering Digital Lock Indicator Two High Current Op-Amps 5V Reference Output DESCRIPTION The UC1634 series of devices is optimized to provide precision phase locked frequency control for two phase DC brushless motors. These devices include most of the features of the general purpose UC1633 Phase Locked Control family and also provide the out-of-phase commutation signals required for driving two phase brushless motors. Only an external power booster stage is required for a complete drive and control system. The two commutation outputs are open collector devices that can sink in excess of 16mA. A disable input allows the user to simultaneously force both of these outputs to an active low state. Double edge logic, following the sense amplifier, doubles the reference frequency at the phase detector by responding to both edges of the input signal at Pin 7. BLOCK DIAGRAM 6/93 UC1634 UC2634 UC3634 ABSOLUTE MAXIMUM RATINGS (Note 1, 2) Input Supply Voltage (+VIN). . . . . . . . . . . . . . . . . . . . . . . . +20V Reference Output Current . . . . . . . . . . . . . . . . . . . . . . . -30mA Op-Amp Output Currents . . . . . . . . . . . . . . . . . . . . . . . . ±30mA Op-Amp Input Voltag...