摘要:
Approaches for a hard-disk drive (HDD) having a balanced resistive temperature detector (RTD). A HDD includes a head slider comprising a single RTD. A read/write IC comprises a balance resistor having the same resistance as the single RTD when the head slider is not in physical contact with the disk. The same amount of current flows through the single RTD and the balance resistor except when the head slider is in physical contact with the disk. Detecting a voltage change across the single RTD enables physical contact between the head slider and the disk to be accurately detected using a circuit with low noise. Alternately, the head slider may include two RTDs connected in sequence, and the balance resistor may possess the same resistance as the two RTDs. The two RTDs may vary inversely with environmental changes to avoid the need to recalibrate the balance resistor after any environmental change.
摘要:
Approaches for a hard-disk drive (HDD) having a balanced resistive temperature detector (RTD). A HDD includes a head slider comprising a single RTD. A read/write IC comprises a balance resistor having the same resistance as the single RTD when the head slider is not in physical contact with the disk. The same amount of current flows through the single RTD and the balance resistor except when the head slider is in physical contact with the disk. Detecting a voltage change across the single RTD enables physical contact between the head slider and the disk to be accurately detected using a circuit with low noise. Alternately, the head slider may include two RTDs connected in sequence, and the balance resistor may possess the same resistance as the two RTDs. The two RTDs may vary inversely with environmental changes to avoid the need to recalibrate the balance resistor after any environmental change.
摘要:
Approaches for a distributed temperature detector architecture in a head disk interface system of a hard-disk drive (HDD). A HDD may include a read/write head comprising a read element and a write element and a read/write integrated circuit (IC). The read/write head may comprise (a) a first temperature sensor that is located relatively near an air bearing surface (ABS) of the read/write head and (b) a second temperature sensor that is offset from the ABS. The read/write IC is configured to detect when the read/write head makes physical contact with a disk based on a difference in temperature measured by the first and second temperature sensor. The first and second temperature sensors form a bridge circuit, such as a Wheatstone bridge, with a first IC resistor and a second IC resistor that both reside in the read/write IC, allowing the temperature of the read/write head to be accurately measured.
摘要:
Approaches for a distributed temperature detector architecture in a head disk interface system of a hard-disk drive (HDD). A HDD may include a read/write head comprising a read element and a write element and a read/write integrated circuit (IC). The read/write head may comprise (a) a first temperature sensor that is located relatively near an air bearing surface (ABS) of the read/write head and (b) a second temperature sensor that is offset from the ABS. The read/write IC is configured to detect when the read/write head makes physical contact with a disk based on a difference in temperature measured by the first and second temperature sensor. The first and second temperature sensors form a bridge circuit, such as a Wheatstone bridge, with a first IC resistor and a second IC resistor that both reside in the read/write IC, allowing the temperature of the read/write head to be accurately measured.
摘要:
A thermal-assisted magnetic recording (TAMR) system is described which generates laser-pulse signals from the write data line. Additionally, training signals for initial synchronization are fed to the preamp IC using the write data line during servo read cycle. This requires no increase in the number of wires going to read-write driver chip (R/W IC) (preamp). In embodiments of the invention the R/W IC also includes registers that are set using serial data from the system electronics to influence the characteristics of the drive signal to the laser.
摘要翻译:描述了从写入数据线产生激光脉冲信号的热辅助磁记录(TAMR)系统。 此外,初始同步的训练信号在伺服读周期期间使用写数据线馈送到前置放大器IC。 这不需要增加读写驱动器芯片(R / W IC)(前置放大器)的数量。 在本发明的实施例中,R / W IC还包括使用来自系统电子装置的串行数据设置以影响到激光器的驱动信号的特性的寄存器。
摘要:
A method, apparatus, and system are provided for implementing spin-torque oscillator sensing with an enhanced integrated demodulator for hard disk drives. The demodulator receives an input signal from a STO read sensor having an oscillation frequency ω related to the strength of the detected magnetic signal field. The demodulator includes a pair of mixers coupled to a quadrature reference oscillator with respective quadrature components cos(ω0t), and sin(ω0t) of the quadrature reference oscillator being mixed with a received input signal to form signals at the sum and difference frequencies, ω±ω0. Each of these mixer products is lowpass filtered by a respective a lowpass filter to remove the sum frequency components for providing a demodulator output signal that is directly proportional the STO oscillation frequency ω. The demodulator output signal is used for processing by data detection electronics.
摘要:
A method, apparatus, and system for implementing spin-torque oscillator (STO) sensing with an enhanced delay control feedback circuit for hard disk drives. A detector receives an input signal from a STO read sensor having an oscillation frequency related to the strength of the detected magnetic signal field. The received input signal is mixed with a time delayed input signal for providing a detector output signal. A low frequency component signal of the detector output signal is monitored and a delay control feedback is applied to an adjustable time delay to bias the DC signal of the detector output signal.
摘要:
A method, apparatus, and system are provided for implementing spin-torque oscillator sensing with an enhanced integrated demodulator for hard disk drives. The demodulator receives an input signal from a STO read sensor having an oscillation frequency ω related to the strength of the detected magnetic signal field. The demodulator includes a pair of mixers coupled to a quadrature reference oscillator with respective quadrature components cos(ω0t), and sin(ω0t) of the quadrature reference oscillator being mixed with a received input signal to form signals at the sum and difference frequencies, ω±ω0. Each of these mixer products is lowpass filtered by a respective a lowpass filter to remove the sum frequency components for providing a demodulator output signal that is directly proportional the STO oscillation frequency ω. The demodulator output signal is used for processing by data detection electronics.
摘要:
A method, apparatus, and system are provided for implementing spin-torque oscillator (STO) sensing with a demodulator for hard disk drives. The demodulator measures an instantaneous phase of the readback signal from a STO sensor and converts the readback signal into a signal that is proportional to the magnetic field affecting the STO frequency during a bit time. The converted signal is used for processing by conventional data detection electronics.
摘要:
A method, apparatus, and system are provided for implementing spin-torque oscillator (STO) sensing with a demodulator for hard disk drives. The demodulator measures an instantaneous phase of the readback signal from a STO sensor and converts the readback signal into a signal that is proportional to the magnetic field affecting the STO frequency during a bit time. The converted signal is used for processing by conventional data detection electronics.