Hardware Reference
In-Depth Information
Figure 9.37
Audible alarm with output to a moving coil loudspeaker
Photo 9.10
Various audible and ultrasonic transducers
and output ENABLE control lines coupled to eight bipolar Darlington driver
transistors. This configuration provides an extremely low-power latch with a
very high-output current capability.
The eight outputs of the UCN5801 are all open-collector, the positive supply
voltage for which may be anything up to 50 V. Each Darlington output device
is rated at 500 mA maximum however; if that should prove insufficient for
a particular application then several output lines may be paralleled together
subject, of course, to the limits imposed by the rated load current of the high-
voltage supply.
Figure 9.39 shows a typical arrangement of the UCN5801 in which the load
voltage supply is
+
12 V. The state of the bus is latched to the output of ICI
whenever the STROBE input is taken high; however, when used in conjunction
