IMP183 4/A/D
Application Information
Reset Output Signal
Reset output signals are valid as long as either voltage at 5V
IN
or 3.3V
IN
is above 1.2V. In addition, the IMP1834 has push-pull
outputs that can remain valid below a 1.2V input level. To sink
current below 1.2V, a resistor should be connected from the reset
output to ground. This resistor guarantees a valid reset signal
down to 0V. A 100kΩ value is suggested.
The IMP1834A open drain reset outputs require pull-up resistors
and must be low enough in value to pull the output into a HIGH
state. Resistor value is not critical in most applications and a value
of 10kΩ is suggested. See
Figure 5
and
Figure 6.
The IMP1834A open drain reset outputs can be connected to the
same potential through a single pull up resistor. In this configura-
tion a failure on either supply will generate an active LOW reset.
If the outputs are pulled-up to different voltages, the reset outputs
(pin 2 and pin 7) should not be connected. See
Figure 7.
5V
IMP1834A
10kΩ
1
2
3
4
5V
IN
3.3V
IN
8
7
6
5
10kΩ
3.3V
5VRESET 3.3VRESET
5VTOL
GND
3.3VTOL
PBRST
1834_07.eps
Figure 6. IMP1834A Open Drain Output Pull-Up Resistor
5V
3.3V
IMP1834A
1
2
5V
IN
3.3V
IN
8
7
6
5
10kΩ
5V or 3.3V
RESET
µP
Input
100kΩ
1834_06.eps
5VRESET 3.3VRESET
5VTOL
GND
3.3VTOL
PBRST
3
Figure 5. IMP1834 RESET Valid to 0V
4
1834_08.eps
Figure 7. IMP1834A Wired “OR” Connection
6
408-432-9100/www.impweb.com
©
1999 IMP, Inc.
A1PROS [ A1 PROS CO., LTD. ]
