LD7000

www.DataSheet4U.com LD7000 Spindle/VCM Controller and Pre-driver DESCRIPTION The LD7000 Servo and Spindle Predriver, a CMOS monolithic integrated circuit housed in a 64-lead TQFP package operates from +5 V and +12 V supplies. It is designed to drive a voice coil actuator and a 3-phase, Hall-sensorless motor with external power MOSFETs. The device is intended for use in 12 V disk drive applications. The actuator driver includes a saturation detector to monitor the loop compensation amplifier for saturation, an uncommitted opamp for input signal conditioning, a voltage reference to provide a precise voltage level for internal PWM buffers, and reduced power dissipation. The spindle driver includes a µP controlled startup ramp to replace the imprecise analog ramp, an external PWM input to allow PWM frequencies above the audible range, active pullup on the P driver, adjustable N-channel slew rate, and improved spindle brake performance. A precision low voltage monitor circuit is also added DataSheet4U.com to monitor +5 V and +12 V supplies and to initiate servo head retracts during voltage faults. All functions are controlled by an SSI compatible read/write serial port. Three DC-DC converter circuits for 2.5V,3.3V,&-3/5Vsupplies are also available for digital chips and MR bias negative supply. FEATURES Small footprint 64 or 48 pin TQFP package Spindle driver is PWM during run and start Commutator is driven by a phase lock loop for high jitter immunity Adjustabl...