All pins provide overvoltage protection circuits by using suppressor
diodes. They short‑circuit external voltage spikes above 6 V to
ground.
The interrupt inputs have TTL input levels with the following
characteristics.
Electrical characteristics
Parameter Value
Min. Max.
Input voltage High
Low
2.0 V
0 V
5.0 V
0.8 V
Power-up default The inputs are set to a defined
logical high level by the built-in
10 kΩ pull-up resistors.
Recognizing User Interrupts
To allow the interrupt controller to recognize incoming user
interrupts, the input of the interrupts must be kept high for at least
100 ns. The interrupt is activated by the high to low transition of the
signal. The signal must remain low for at least 100 ns after the
transition.
high
low
t
T
high
T
low
T
high min
:
100 ns
T
low min
:
100 ns
Requests for recognizing
s
Signal Connection to External Devices
t
176
s
DS1103 Hardware Installation and Configuration November 2014