Title :
150 MHz Preamplifier for Magneto-Resistive Heads
Author :
Ramalho, J.N. ; Voorman, J.O. ; Veenstra, H. ; Desbonnets, E.
Author_Institution :
Philips Research Laboratories, Prof. Holstlaan 4, Eindhoven, The Netherlands
Abstract :
This paper presents the read section of a 10-channel preamplifier for hard-disk-drive applications that use magneto-resistive-read/inductive-write heads. Ten dedicated low-noise amplifier stages use a current-bias current-sense architecture with grounded magneto-resistive (MR) heads. The amplifier also contains gain stages common to all heads, a high-frequency gain-boost, an MR bias current-DAC and a serial interface to program the IC. The preamplifier is designed in a 2.5 ¿m BiCMOS technology. Measurements using a single supply voltage of 3.8-5.5V show a ¿3 dB bandwidth of 120 MHz (without gain-boost) up to 180 MHz (with some gain-boost) and an input referred noise of 0.9 nV/¿Hz.
Keywords :
Bandwidth; BiCMOS integrated circuits; Breakdown voltage; Electric resistance; Impedance; Low-noise amplifiers; Magnetic heads; Noise reduction; Preamplifiers; Resistors;
Conference_Titel :
Solid-State Circuits Conference, 1995. ESSCIRC '95. Twenty-first European
Conference_Location :
Lille, France
Print_ISBN :
2-86332-180-3
