Guzik MR5-L Read/Write Headamplifier – Discontinued
- Bandwidth from DC to 2 GHz
- Writer driver 2 Gbit/sec
- Head impedance from 100 to 1000
- Ohm Supports heater (single-ended or differential)
- Microactuator compatible
The Guzik MR-5L read amplifier is designed to work with the high-impedance TMR heads. The impedance of such heads can be as high as 1000 Ohm, so it is impossible to achieve a high bandwidth with a high-impedance amplifier. This is the reason, why MR-5L is a current-sense low-impedance amplifier with voltage bias. The MR-5L also incorporates a heater driver and supports connection to a microactuator on a head suspension in order to perform the mechanical and electrical tests of the microactuator. The Guzik high-impedance injector (passive or active) is recommended for the calibration or the performance measurements of the MR-5L.
MR Amplifier 5L Specifications:
Read Amplifier
- Differential current sense low impedance amplifier
- Bandwidth: DC to 2GHz at –3 dB
- Flatness: ±0.5 dB, 0.3 MHz to 1 GHz
- Input noise: 0 (typical)
- TMR bias voltage: programmable ±400 mV in 0.1 mV steps
- TMR impedance measurements accuracy: 1% within the bias voltage range (20 mV to 400 mV)
- Common mode rejection ratio: 24 dB (typical) in full bandwidth (worst 18 dB at 700 MHz)
- Non linear distortion (1 GHz, 1 mV input level): less than 1%
- Amplification: 30 dB**
- Write to read recovery time: 100 nsec (typical) for both Bias On and Shut Down Bias modes***
- Input impedance: 80 Ohm differential (typical)
- Guzik MR5L head amplifier compatibility: with Universal Preamplifier UP8 only.
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* US Patent 7,061,321 B1, Patent pending in Japan
** Required amplification is provided by UP8
*** Measurements conditions: write current 50 mA, head inductance 20 nH, write data 1 Gbit/sec
Write Driver (General Specification)*
- Write data speed: up to 2 Gbit/sec
- Rise/fall time of write current: (10-90%) 300 psec**
- Programmable overshoot: up to 100% of write current in 1% steps
- Output common mode voltage: less than ±0.1 V
- Write current: programmable 2 to 100 mA (zero to peak) in 0.02 mA steps***
- Read to write recovery time: less than 40 nsec
- Head voltage swing: more than 12 V peak to peak
- Output impedance: 100 Ohm differential
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* MR-5L comes with Guzik Write Driver Revision 5 (for more details see the bulletin “Guzik Read/Write Amplifier Revision 5”).
** Measurement conditions: write current 50 mA, 100% overshoot, and L=20 nH in series with R=20 Ohm; current probe Tektronix CT-6.
*** Maximum overshoot value in write current range 50-100 mA should be calculated according with formula I overshoot + I write = 100 mA.
Heater Features:
Single-ended or differential output configurable on the board upon customer request
Output heater voltage: from 0 to 9 V (typical, adjustable upon customer request)
Two types of heater voltage control:
- Internal: with separate control in the read and write modes by an internal DAC
- External (through MCX connector): input range from 0 to 4 V, amplification 2.5 (typical, adjustable upon customer request)
Heater impedance: not less than 50 Ohm.
Rise/Fall time: 100 nsec (defined by 4 MHz low pass filter)
Heater current and voltage measurements:
- Current measurement accuracy ±1.0 mA
- Voltage measurement accuracy ±5.0 mV
Maximum output current: 125 mA
MR-5L Frequency Response
Measurement Conditions: high-impedance injector,
MR-5L only (Left), MR-5L with Guzik Universal Preamplifier 8 (Right)
MR-5L Write-to-Read Recovery Time
Measurement Conditions:
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Write data 200 Mbit/sec
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Write current 50 mA
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High-impedance injector