AT78C7005 Datasheet, PDF (1/4 Pages) ATMEL Corporation – Spindle/VCM MotorController/Drivers

Features
• Operates from Single Supply: 3.3V or 5V
• Small Footprint 64-Pin TQFP Package or Flip Chip
• Precision Low-voltage Monitor Circuitry for the Power Supply
• Master Power on Reset
• Serial Port Interface with Read-back Capability
• Over-temperature Protection/Warning
• Shock Sensor Signal Processing
• On-chip 1.8V, 2.5V and -3V Regulators
• Low Power Consumption, 9 mA in Normal Run Mode
• Spindle Driver
– Commutator is Driven by a FLL for High Immunity to Jitter
– Programmable 10-bit DAC
– Adjustable Slew Rate Control
– External Startup Capability
– 1.0A Current Capability with R_on = 1Ω
– Digital Commutation Delay and Blanking
– Programmable Delay from BEMF Zero Crossing
– External INDEX Signal for Spin Lock
– Active Spindle Braking Capability
• VCM Driver
– 0.4A Current Capability with R_on = 1.5Ω
– Programmable 14-bit DAC
– Ramp Load/Unload Capability with 10-bit ADC
– Power-off Retract with 9V Charge-pump
– Programmable VCM Current Controlled by Sense Resistor
• Available in a Variety of Packages Depending on Customer Requirements
Spindle/
VCM Motor
Controller/
Drivers
AT78C7005
Summary
Description
The AT78C7005 is a CMOS monolithic device that integrates Spindle and VCM con-
trollers as well as power stages into one chip. The device operates from 3.3V or 5V
power supply. The AT78C7005 is designed for a small-form-factor hard disk drive
application.
A precision low-voltage detection circuit monitors the power supply and initiates VCM
retract at voltage fault condition. A 3-line serial port interface with read back capability
provides interface to the microprocessor.
The Spindle driver features a transconductance amplifier, a current sense amplifier,
power output drivers, sequencer, internal delay/masking logic, Spindle brake circuit,
FLL, and charge-pump for locking the spindle to the programmed rotational speed.
The VCM driver features a transconductance amplifier, differential input current sense
amplifier, ramp load/unload capability, and power output amplifier.
3432BS–NETST–5/04
Note: This is a summary document. A complete document
is available under NDA. For more information, please con-
tact your local Atmel sales office.