Browse Prior Art Database

GENERAL-PURPOSE TIME-DOMAIN EQUALIZER

IP.com Disclosure Number: IPCOM000038592D
Original Publication Date: 1987-Feb-01
Included in the Prior Art Database: 2005-Jan-31
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Klaassen, KB: AUTHOR [+2]

Abstract

The proposed time-domain equalizer combines first and second derivative equalizers for use in magnetic recording systems. The circuit incorporates the advantages of differential-in/differential-out signal conditioning, active filtering for signal equalization and independently adjustable components for determining frequency response.

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GENERAL-PURPOSE TIME-DOMAIN EQUALIZER

The proposed time-domain equalizer combines first and second derivative equalizers for use in magnetic recording systems. The circuit incorporates the advantages of differential-in/differential-out signal conditioning, active filtering for signal equalization and independently adjustable components for determining frequency response.

Referring to Fig. 1 for the general case, the transfer function of the time-domain equalizer is given by Vo(t) = a1 Vidt + a2Vi + a3 dVi + .... + an+2 dnVi, (1) dt dtn where a1, a2, a3 and an+2 are weighting factors which are independently adjustable for desired frequency response characteristics. The circuit of the generalized time-domain equalizer is shown in Fig. 2. Here the weighting factors of Equation (1) for direct-coupled configuration are given by a1 = 2RL; a2 = 2RL; a3 = 2C2RL - 4C1 R'LRL; a4 = -4C1C3R'LRL . L R1 R2 If R2 is omitted, the weighting factor for the second order deriviative produced by the circuit is negative. If C2 is left out, the weighting factor for both first and second order derivatives is negative. Similarly, the weighting factors for the cross-coupled configuration of the circuit of Fig. 2, as indicated in dot-dash lines, are given by a1 = 2RL; a2 = 2RL; a3 = - 2C2RL + 4C1 R'LRL; a4 = 4C1C3R'LRL . L R1 R2 Here, if R2 is omitted, the weighting factor for the first order derivative is negative. Without C2, the circuit becomes a second derivative equalizer with indepen...