AS1904, AS1905, AS1906
1 General Description
The AS1904/5/6 family is an ultra low-power supervisory
circuit device.
The device can be used to monitor the supply voltage of
digital systems and microprocessors and initiate a reset
when the voltage goes below a predefined threshold.
The duration of the reset is 5/20/100/500ms (typ.) after
the supply voltage has risen above the threshold.
The device exhibits excellent reliability and can reduce
application costs by eliminating all external components.
The device is available with different output drivers:
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Ultra Low-Power µP Supervisory Circuit
Wor
ld's
L
Pow owest
Con
sum er
2 Key Features
ptio
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Low 150nA (typical) Supply Current
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D a ta S he e t
Precision Monitoring of 2.5-, 3-, and 3.3V-Power
Supplies
Supply Voltage Range 1.0 to 3.6V
Reset Threshold Available from 2.2 to 3.1V
Available in three Versions
- AS1904 Push-Pull RESETN
- AS1905 Push-Pull RESET
- AS1906 Open Drain RESETN
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The AS1904 has a push-pull driver with an active low
reset.
The AS1905 uses the same output stage as the
AS1904, but has an active high reset.
The AS1906 has an open drain output with active low
reset.
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4 Time-Out Periods Ranging from 5 to 500ms
Detection Voltage Accuracy: ±1.5%
Temperature Range: -40 to +85°C
SOT23-3 Package
Superior Upgrade to austriamicrosystems
AS1901/2/3 Device Family
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All devices operate down to a voltage of 1V.
The reset thresholds are factory-trimmable between
2.2V and 3.08V in steps of approximately 100mV.
Each device of the AS1904/5/6 family is offered with four
time-out periods of 5/20/100/500ms.
The extremely low current consumption of only 150nA
(typ) at 3.3V makes the device ideal for use in portable
applications.
All devices are available in a 3-pin SOT23 package.
3 Applications
The devices are ideal for computers, intelligent instru-
ments, controllers, critical microprocessor and micro-
controller, power monitoring and portable/battery-
powered equipment.
Figure 1. Functional Block Diagrams
V
CC
3
V
DD
V
CC
V
CC
3
V
DD
V
CC
AS1904
AS1905
RESET,
RESETN
GND
1
2
Microprocessor
AS1906
RESETN
2
Microprocessor
RESET
RESET I/O
GND
GND
1
GND
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Revision 1.41
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