مرکز منطقه ای اطلاع رساني علوم و فناوري - Wide PRIME-current range for all-magnetic shift registers

Abstract :

In an all-magnetic resistance-type shift register, a PRIME current pulse $i_{p}(t)$ , of amplitude Ip, is applied to Npand Nbturns through the minor and major apertures, respectively. For given operation frequency $f$ , the ratio $R = I_{p}^{\\max }/I_{p}^{\\min}$ , where $I_{p}^{\\min} < I_{p} < I_{p}^{\\max }$ is the PRIME range of bistable operation, is maximized by matching $N_{p}/N_{b}$ so that $I_{p}^{\\max }$ values determined by spurious ZERO buildup and ONE dropout are the same. For a rectangular (or dc) $i_{p}(t)$ , the matched $N_{p}/N_{b}$ is fixed by the core properties, and R^maxis limited (e.g., <7). However, if $i_{p}(t)$ rises gradually, the matched $N_{p}/N_{b}$ depends also on the rise time Trof $i_{p}(t)$ . The lower $f$ is, with corresponding larger Tr, the smaller is the matched $N_{p}/N_{b}$ , and the larger is R^max. Calculation of $R$ is carried for ramp and half-sinusoidal $i_{p}(t)$ waveforms. The latter, for instance, at $T = 25\\deg$ C yields R^maxvalues of 14.0 and 22.0 for $f$ of 1.0 and 0.5 kc/s respectively. Such wide PRIME ranges permit reliable register operation in a wide temperature range without resorting to temperature compensation of Ip. Experimental results are in agreement with the calculation.