adm1232arm-reel Analog Devices, Inc., adm1232arm-reel Datasheet - Page 5

• Manufacturer Part Number: adm1232arm-reel
• Description: Microprocessor Supervisory Circuit
• Manufacturer: Analog Devices, Inc.

REV. B
CIRCUIT INFORMATION
PB RESET
The PB RESET input makes it possible to manually reset a system
using either a standard push-button switch or a logic low
input. An internal debounce circuit provides glitch immunity
when used with a switch, reducing the effects of glitches on the
line. The debounce circuit is guaranteed to cause the ADM1232
to assert a reset if PB RESET is brought low for more than 20 ms
and is guaranteed to ignore low inputs of less than 1 ms.
PB RESET
Figure 2. Typical Push Button Reset Application
RESET
RESET
PB RESET
GND
V
V
CC
CC
ADM1232
V
ADM1232
ADM1232
IL
Figure 3. PB RESET
TOLERANCE
TOLERANCE
PB RESET
STROBE
STROBE
DELAY
RESET
TD
RESET
PB RESET TIME
MICROPROCESSOR
I/O
RESET
V
RESET ACTIVE
IH
TIME
–5–
STROBE Timeout Selection
TD or time delay set is used to set the Strobe Timeout Period.
The Strobe Timeout Period is defined as being the maximum
time between high-to-low transitions (Figure 4) that STROBE
will accept before a reset will be asserted. The Strobe timeout
settings are listed in Table I.
Condition
TD = 0 V
TD = Floating
TD = V
TOLERANCE
The TOLERANCE input is used to determine the level V
vary below 5 V without the ADM1232 asserting a reset. Con-
necting TOLERANCE to ground will select a –5% tolerance
level and will cause the ADM1232 to generate a reset if V
falls below 4.75 V (typical). If TOLERANCE is connected to
V
ADM1232 to generate a reset if V
Check the parameters for the V
Specifications for more information.
RESET AND RESET OUTPUTS
While RESET is capable of sourcing and sinking current,
RESET is an open drain MOSFET which sinks current only.
Therefore, it is necessary to pull this output high.
CC
RESET OUTPUT DELAY
WHEN IS V
a –10% tolerance level is selected and will cause the
RESET
RESET
CC
STROBE
V
CC
CC
FALLING
PULSE WIDTH
STROBE
Figure 4. STROBE Parameters
+5V
Figure 5. Reset Output Delay
STROBE TIMEOUT PERIOD
Min
62.5
250
500
+4.25V (10% TRIP POINT)
+4.5V (5% TRIP POINT)
Table I.
CC
Typ
150
1200
600
CC
trip point in the ADM1232
falls below 4.5 V (typical).
Max
250
1000
2000
ADM1232
RESET OUTPUT DELAY
WHEN IS V
+5V
CC
RISING
Units
ms
ms
ms
CC
CC
can