AS1904, AS1905, AS1906
Ultra Low-Power µP Supervisory Circuit
austriamicrosystems
Data Sheet
www.austriamicrosystems.com Revision 1.4 1 - 9
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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The AS1904 has a push-pull driver with an active low
reset.
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The AS1905 uses the same output stage as the
AS1904, but has an active high reset.
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The AS1906 has an open drain output with active low
reset.
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.
Figure 1. Functional Block Diagrams
2 Key Features
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Low 150nA (typical) Supply Current
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Precision Monitoring of 2.5-, 3-, and 3.3V-Power
Supplies
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Supply Voltage Range 1.0 to 3.6V
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Reset Threshold Available from 2.2 to 3.1V
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Available in three Versions
- AS1904 Push-Pull RESETN
- AS1905 Push-Pull RESET
- AS1906 Open Drain RESETN
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4 Time-Out Periods Ranging from 5 to 500ms
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Detection Voltage Accuracy: ±1.5%
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Temperature Range: -40 to +85°C
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SOT23-3 Package
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Pin Compatible to MAX6326/6327/6328
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Superior Upgrade to austriamicrosystems
AS1901/2/3 Device Family
3 Applications
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Computers
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Intelligent Instruments
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Controllers
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Critical Microprocessor and Microcontroller
Power Monitoring
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Portable/Battery-Powered Equipment
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Automotive
VCC
AS1906 Microprocessor
VDD
GND GND
RESETN RESET I/O
VCC
1
2
3
VCC
AS1904
AS1905
Microprocessor
VDD
GND GND
RESET,
RESETN
RESET
VCC
1
2
3
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