(1 PC) ML4404YCQ MICRO LINEAR Interface Circuit, BIPolar, PLCC-28

GENERAL DESCRIPTION

The ML4404 Trajectory Generator provides the

trajectory function for time optimal head positioning

systems. The ML4404 receives position and velocity

information from a servo controller, such as the

ML4403, and generates the desired time optimal

velocity trajectory. Desired Velocity is then compared

with the actual velocity to create the error signal used by the servo controller.

An anticipate function is included to compensate for phase shift error caused by actuator inductance.

Another feature on the ML4404 is an error measure

output which averages the velocity error during

deceleration, so that the control system can monitor

and adjust the necessary transducer gain for minimum

access time.

The servo system usually requires accurate analog voltages to be set through software control. This is

easily accomplished with a duty cycle to current

translator function on the ML4404. By controlling the

duty cycle of a TTL line, a processor can set an analog voltage on the translator output. These translators are

fully independent blocks which can be used anywhere

in the control system.