IMP49P504

The IMP49P504 has the following features including 4 channels;70MHz BW;MIR element biasing;Curent bias&current sense scheme;Single-ended input, differential output;Resistor programmable MR bias current;MR voltage clamp protection.

The IIVVIP49P504 is a combination four-input magneto-resistive pre-amplifier and four-output thin film write driver. IMP49P504 is ideally suited for mass storage applications utilizing advanced MR head technology,such as hard disk and tape drives.The 1112P49P504 can operate in either a read or write mode.During the read mode the write current is disabled.The pre-amplifier can be used with read and servo carrier signals. The preamp input stage provides bias current for the magneto-resistive elements. Current is sourced from the single-ended input pins into the MR element while amplifying the AC signal generated across the element. The bias current of IMP49P504 is set by an external resistor to ground.The write driver of IMP49P504 is implemented in an H-bridge configuration for non-center-tapped thin film elements. A four-charnel differential output multiplexor is used. Ihe outputs are allowed to swing up to 7 volts above VSS, thus improving switching time. Write current is set by an externalresistor to ground.The write driver is totally disabled for low or nonvalid values of VDD, such as during device power-up or power-down. A Write-Un-Safe indicator pin is provided.Write Unsafe output A high level indicates that an unsafe condition of the supply has been detected. Output is forced high during PD mode.

Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the consequences of use of such information norfor any infringement of patents or other rights of third partieswhich may result from IMP49P504 use. No licence is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics.Specifications mentioned in this publication are subject to change without notice. IMP49P504 publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics.