L6327 STMICROELECTRONICS | Alldatasheet
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Technical content
This is preliminary information on a new product now in development. Details are subject to change without notice. ■ Power Supplies +5Vdc, -5Vdc ■ Current bias or voltage bias (selectable) / Differential Voltage Sense architecture ■ 6 or 4 channel versions ■ 38-pin TSSOP package (for either 6 or 4 channels) ■ Internal reference Resistor for read and write currents ■ Read channel -3dB bandwidth > 400MHz (Rmr=50 ohm no interconnect) ■ Input equivalent preamplifier voltage noise 0.5nV/rtHz nominal ■ Input equivalent MR bias current noise 10 pA/ rtHz nominal ■ MR bias current programmable (5 bit DAC) 1.5- 7.0mA nominal MR bias voltage programmable (5 bit DAC) 65-335mV nominal ■ Programmable gain (100V/V, 150, 200 and 250V/V) and read bandwidth ■ Write frequency up to 300 MHz (Lh=70nH, Rh=20 ohms, Ch=2pF, VEE=-5V) ■ Rise/Fall time 0.6ns ( Iw =40mA 0-pk, Lh=70nH, Rh=20 ohms, Ch=2pF, VEE=-5V) ■ Write current programmable (5 bit DAC) 15-60mA ■ PECL write data input ■ Bi-directional 16-bit TTL Serial interface for head selection, read/write currents selection, chip parameters modification, chip enable, vendor code and fault status read back registers ■ 2-pin mode selection (R/W, MRR) ■ Bank write feature for servo write ■ Digital buffered head voltage DBHV / Analog buffered head voltage ABHV pin (gain 5) ■ Thermal asperity detection & correction with adjustable sensitivity level (6 bit DAC) ■ Automatic successive approximation digital measurement of temperature and Rmr (7 bits) ■ Read and write head open/short detection, low low supply detect and temperature monitoring (high temperature warning and Analog Temperature Diode Voltage measurement) ■ Low write frequency detection. ■ WRITE to READ fast recovery 150ns (same head, including 100ns blanking period) ■ Head-to-head switch in READ mode - 10µs (nom) ■ Head and MR bias current switching transient current head protection ■ READ-to-WRITE switching 50ns (same head) ■ Programmable read bias during write and bank write operation ■ ESD diode for GMR head protection
DESCRIPTION
L6327/L6332 is a BICMOS monolithic integrated cir- cuit GMR differential preamplifier designed for use with four-terminal magneto-resistive GMR read/in- ductive write heads. It is available as either a six (L6327) or four (L6332) channel device. The devices consist of a voltage-sense, current-bias or voltage- bias (selectable), differential input and differential output, low-noise, high bandwidth read amplifier and include fast current switching write drivers which sup- port data rates in excess of 550 Mb/s with 70nH write heads. The GMR preamplifier provides programmable read current / voltage bias and write current (5 bit DAC for the read bias, 5 bit DAC for the write current), fault detection circuitry and servo writing features. Read amplifier gain, write current wave shape (overshoot, undershoot and damping) can be adjusted and a thermal asperity detection and correction circuit can be enabled and programmed with different thresh- olds (6 bit DAC) through a 16-bit bi-directional serial interface (SDEN, SDATA, SCLK). The device oper- ates from a +5V supply and a -5V supply (nominal). No external components are required as a trimmed or untrimmed resistor for reference current setting is employed. TSSOP38 ORDERING NUMBERS: L6327 L6332 PRODUCT PREVIEW 6 / 4 CHANNEL VOLTAGE SENSE GMR PREAMPLIFIER
VCC (+5V) VGND (0V) VEE (-5V) WDP WDN FLT SDATA SCLK SEN MRR ABHV/ ADTV RDP RDN HW0P HW1/5P FAULT PROCESSOR Low supply detection, Open/short heads, TA detection, low write frequency, high temperature SERIAL INTERFACE CONTROL HEAD SELECTION MODE CONTROL VREF MR READ INPUT STAGES Imr, Iwr RW enable head select WRITE DAC READ DAC Rdamp Overshoot, Undershhotlow bias TA detection, TA correction ABHV, MR meas Temperature monitoring Gain boost, Low pass filter current/voltage HR0P HR0N HR1/5P HR1/5N L6327/L6332 6/4 CH High pass filter A2D RMR, temp
Thin Shrink Small Outline Package c k A be D E Pin 1 identification 38 20 TSSO3 8M Gage Plane 0.25mm L 0.010 mm SEATING PLANE 0.004 inch SEATING PLANE DIM. mm inch A 1.10 0.043 A1 0.05 0.15 0.002 0.006 b 0.17 0.27 0.007 0.011 c 0.09 0.20 0.0035 0.008 E 6.40 0.252 e 0.50 0.020 k 0˚ (min.) 8˚ (max.) OUTLINE AND MECHANICAL DATA
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics 2001 STMicroelectronics - All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - China - Finland - France - Germany - Hong Kong - India - Italy - Japan - Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - U.S.A. http://www.st.com L6327 - L6332