ASM1834A/D
Pin Configuration
*AS1834D reset outputs are active HIGH (5V RESET and 3.3V RESET) Outputs are open-drain for AS1834A.
Pin Description
Pin #
Pin Name
Function
1
5VIN
5V RESET
5V RESET
5V TOL
GND
5V power supply input.
5V reset output (Active LOW, ASM1834, ASM1834A. Open drain outputs for ASM1834A).
5V reset output (Active HIGH, AS1834D).
2
3
4
5
5V input tolerance select: 10% tolerance for 5VTOL= 5VIN and 5% tolerance for 5VTOL = GND
Ground.
Debounced manual pushbutton reset input (40kΩ internal pull-up).
PBRST
3.3V input tolerance select: 20% tolerance for 3.3VTOL = 3.3VIN and 10% tolerance for
3.3VTOL=GND.
6
3.3V TOL
3.3V RESET
3.3V RESET
3.3VIN
3.3V reset output (Active LOW, ASM1834, ASM1834A. Open drain outputs for ASM1834A).
3.3V reset output (Active HIGH, AS1834D).
7
8
3.3V power supply input.
Detailed Description
Operation Power Monitor
The ASM1834 supervisors simultaneously detect out-of-
tolerance power supply conditions on both 3.3V and 5V
power supplies. If the voltages at 5VIN or 3.3VIN are
outside the tolerance band, the reset for the falling supply
voltage becomes active. When the monitored supply
returns to an intolerance state, the reset remains active
for approximately 350ms before returning to the inactive
state.
On power-up, the reset signals are kept active for
approximately 350ms after the power supply voltages
have reached the selected tolerance. This allows the
power supply and microprocessor to stabilize before the
reset is removed.
All supply current for the ASM1834 devices is drawn from
the input (5VIN or 3.3VIN) with the highest voltage level.
The outputs draw current from their input supplies 5VIN
and 3.3VIN.
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