Disk Device Actuator Driver Noise Isolation via FPC Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Disk devices, such as hard disk drives, face noise propagation issues due to high impedance in wiring between the driver and actuator, which can interfere with data reading and writing and positioning control, leading to inaccurate data retrieval and writing.
Innovation Solution
The implementation of a flexible printed circuit board (FPC) with separate connections for the preamplifier and actuator driver, where the actuator driver is mounted apart from the preamplifier, reduces noise propagation by using high-impedance wiring for drive signals and low-impedance wiring for digital signals, and the actuator drivers are connected to the FPC rather than the PCB to minimize noise interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the actuator driver is mounted on the same PCB as the preamplifier, then the device complexity is reduced, but noise propagation occurs between high-voltage drive signals and digital signals
Solution Approach 1:
The patent divides the circuit board into two separate flexible printed circuit boards (FPCs): one for the preamplifier and another for the actuator driver. This segmentation physically isolates high-voltage drive signals from digital signals, preventing noise propagation while maintaining functional integration within the disk device.
Solution Approach 2:
The actuator driver is extracted from the preamplifier circuit board and mounted on a separate FPC. This extraction removes the source of high-voltage noise from proximity to sensitive digital signal pathways, eliminating the harmful electromagnetic interference while preserving the compact form factor.
2Power
If high-voltage drive signals are routed through long wiring, then the actuator can be driven effectively, but impedance increases and noise propagation occurs
Solution Approach 1:
A separate FPC acts as an intermediary carrier dedicated to high-voltage drive signals. This dedicated pathway minimizes signal degradation and noise pickup by providing a controlled impedance environment isolated from digital signal interference, ensuring reliable power delivery to the actuator.
Solution Approach 2:
The patent applies different wiring characteristics to different signal types: the actuator driver FPC uses wiring optimized for high-voltage analog drive signals, while the preamplifier FPC uses wiring optimized for digital signals. This local optimization of wiring quality for each signal type ensures both effective power delivery and signal integrity.
Data Source
AI summary
According to one embodiment, a disk device includes a recording medium, a suspension, a magnetic head, an actuator, a circuit board, an FPC, a preamplifier, and an actuator driver. The magnetic head and the actuator are mounted on the suspension. The circuit board includes a control circuit. The FPC is connected to the suspension and the circuit board. The preamplifier is mounted on the FPC, outputs a write signal, to the magnetic head, corresponding to information to be written to the recording medium by the magnetic head, and receives, from the magnetic head, a read signal corresponding to information read from the recording medium by the magnetic head. The actuator driver is mounted apart from the preamplifier on the FPC, the actuator driver that outputs a drive signal for driving the actuator to the actuator.