Variations in SET pulse shapes in the LM124A and LM111

Abstract

We present a paper that shows remarkable variation in Single-Event Transient (SET) pulse signal shape of the LM124 Operational Amplifier, and the LM111 Voltage Comparator. Both the data and the test methods used are presented.

Modification of the LM124 Single Event Transients by Load Resistors

“…3 is called Q12 at the datasheet by National Semiconductors [12]. The actual structure has been determined by several authors [7], [8], [10], [19], [20], although there are minor changes among the schematics provided by the different works. In particular, Fig.…”

“…The internal topology of the LM124 (Fig. 4) has been depicted in several papers [7], [8], [10], [19], [20] although scarce information is provided about the characteristic of the internal transistors. In fact, the typical procedure is separating the individual transistors by means of laser or ion beams and extract the SPICE parameters using a microprobe and specific instrumentation [18].…”

Load resistor as a worst-case parameter to investigate single-event transients in analog electronic devices

“…They are usually very long since the recovery is controlled by the slew rate value (~ 0.3-0.5 V/µs). R1 is actually an open-base NPN transistor working as a resistor to drain the excess of current from the Q09 base [10]. Transients are usually sharp positive peaks followed by a negative peak the recovery of which is controlled by the slew rate value.…”

“…The SPICE micromodel was created from a source found in the literature [10] with typical transistor parameters [14]. Despite the differences due to the micromodel approximations, Figs.…”

“…A lot of factors affect the shape of these transients: The kind and energy of the ion, the sort of technology, the feedback network, the input values, etc [2][3][4][5][6][7][8][9][10][11]. Load effects have been studied in several structures although attention is usually paid on capacitive loads putting aside other kinds such as load or pull-up resistors.…”