LC7991

The LC7991 is designed as the PLL-type speed controller for constant-speed DC motors. This device incorporates a crystal osillator to provide highly-accurate speed control. Internal frequency dividers support a wide range of motor speeds from low-speed gear motors to high-speed polygon mirror motors. Integrated DACs and a phase comparator allow implementation of a DC motor control system with a minimum of external components. Applications of this device include drum, paper feed and scanner motors for plain paper copiers, laser facsimile equipment, laser printers, as well as motors for floppy, hard and optical disk drives.

Features of the LC7991 are:(1)wide 200 to 2500 Hz operating frequency range (FGI input);(2)low-impedance phase and frequency control outputs;(3)speed lock indicator output directly drivers an external LED;(4)TTL-compatible motor frequency sensor and run / stop control inputs;(5)CMOS process;(6)single 5V supply.

The absolute maximum ratings of the LC7991 can be summarized as:(1)maximum supply voltage: -0.3 to +7.0 V;(2)input voltage: -0.3 to VDD+0.3 V;(3)output voltage: -0.3 to VDD+0.3 V;(4)output current: +/-20 mA;(5)allowable power dissipation: 300 mW;(6)operating temperature: -30 to +75;(7)storage temperature: -55 to +125. If you want to know more information such as the electrical characteristics about the LC7991, please download the datasheet in www.seekic.com or www.chinaicmart.com .