AS1925 Datasheet, PDF (1/12 Pages) ams AG – Ultra-Low Voltage Microprocessor Supervisory Circuit with Manual Reset

AS1925, AS1926
Ultra-Low Voltage Microprocessor Supervisory
Circuit with Manual Reset
Data Sheet
1 General Description
2 Key Features
The AS1925/AS1926 microprocessor supervisory cir-
cuits were designed to assert a single reset if the moni-
tored supply voltage drops below its reset threshold or if
the manual reset is activated. The reset remains
asserted for a fixed timeout delay after VCC has risen
above the reset threshold and the manual reset is deas-
serted.
Their small size, excellent circuit reliability, and low sup-
ply current (3.5µA) make the AS1925/AS1926 a very
low cost solution by eliminating external components
and adjustments when used with low-voltage (+0.9 to
+1.5V) systems.
The devices are available as the standard products
listed in Table 1.
Table 1. Standard Products
Model
Output Type
AS1925
Active-Low Push/Pull,
Active-High Push/Pull
AS1926
Active-High Push/Pull,
Active-Low Open-Drain
The active-low open-drain reset output requires a pullup
resistor that can be connected to a voltage from 0 to
VCC. The reset comparator was specifically designed to
ignore fast VCC transients.
The devices are available in a 5-pin SOT23 package.
! Factory-Trimmed Reset Thresholds for Monitoring
Supplies from 0.9 to 1.5V
! Low Power Consumption: 3.5µA
! Reset Threshold Accuracy Over Temperature:
±2.5%
! Four Timeout Periods: 1.5ms, 30ms, 210ms, and
1.68s
! Three Reset Output Types:
- Active-Low Push/Pull
- Active-High Push/Pull
- Active Low Open-Drain
! Guaranteed Reset Valid to VCC = 0.55V (Active-
Low)
! Manual Reset Input
! Immune to Fast VCC Transients
! 5-pin SOT23 Package
3 Applications
Figure 1. Block Diagram and Pinout
The device is ideal for portable and battery-powered
systems, embedded controllers, intelligent instruments,
automotive systems, telecommunications equipment,
networking equipment, computer workstations and serv-
ers, critical CPU monitoring applications, and any low-
voltage application.
4
MRN
5
VCC
MRN
+
–
Pullup
VREF
+
–
AS1925/
AS1926
Manual Reset
Detect
Reset Timeout
Period
Reset
Output
3
RESET
1
RESETN
RESETN 1
5 VCC
AS1925/
GND 2 _AS1926
RESET 3
4 MRN
GND 2
www.austriamicrosystems.com
Revision 1.00
1 - 12