1–2 Getting Started
1.1 Overview
The SIM964 Analog Limiter is a digitally programmable signal lim-
iter with a fully analog signal path. User-defined upper and lower
voltage limits, in the range of ±10 V, define a linear operating band
for input signals from DC to 1 MHz.
The user can select an upper voltage limit, VUL, and a lower voltage
limit, VLL, either remotely, or from the front panel. While the input
signal, Vi, is within the range defined by the upper and lower limits,
the SIM964 output, Vo, is a unity-gain buffered signal that follows the
input signal. If the input signal exceeds one of the limits, the output
of the SIM964 will be clamped to that limit for as long as the signal
is in excess of the limit. When the input signal returns to the range
between the limits, the output immediately recovers and follows the
input signal again.
Mathematically, this can be expressed as
Vo=
VUL Vi>VUL
ViVUL ≥Vi≥VLL
VLL Vi<VLL
The input and output signals are applied to the SIM964 through
BNC connections on the front panel. Two TTL monitor outputs,
corresponding to upper and lower limit saturation conditions, are
provided through rear-panel BNC connections. The TTL output
level is +5 V when the corresponding limit is not exceeded, and falls
to 0 V for as long as the input is in excess of the limit.
SIM964 Analog Limiter
