AME, Inc.
AME8570
n
General Description
The AME8570 family allows the user to customize the
CPU reset function without any external components.
The user has serveral choice of reset voltage thresholds,
reset time intervals, and output driver configurations, all
of which are preset at the factory.
These circuits monitor the power supply voltage of
µP
based systems. When the power supply voltage drops
below the voltage threshold a reset is asserted immedi-
ately ( within an interval T
D1
). The reset remains asserted
after the supply voltage rises above the voltage threshold
for a time interval, T
D2
. The reset output may be either
active high ( RESET ) or active low ( RESETB ). The
reset output may be configured as either push/pull or
open drain. The state of the reset output is guaranteed
to be correct only when supply voltage is greater than
1V.
The AME8570 also provide a reset manually by pulling
the MRB input to ground.
Space saving SC-70 package and micropower quies-
cent current ( < 5.0µA ) make this family a natural for
portable battery powered equipment.
GND
µProcessor
Supervisory
n
Functional Block Diagram
AME8570 Push-Pull RESET/ RESETB
IN
R1
I1
Delay
R2
GND
V
REF
N1
P1
RESET/
RESETB
AME8570 Open-Drain RESET/RESETB
IN
R1
I1
Delay
RESET/
RESETB
N1
R2
V
REF
n
Features
l
Small Packages : SC-70, SOT-23
l
Tight Voltage Threshold Tolerance :
± 1.50%
l
Wide Temperature Range : -40
O
C to 85
O
C
l
Low Quiescent Current < 5.0
µA
l
Manual Reset Input Option
l
All AME's Lead Free Products Meet RoHS
Standards
AME8570 Push-Pull RESET/ RESETB with MRB
MRB
IN
R1
I1
Delay
R2
GND
V
REF
N1
P1
RESET/
RESETB
AME8570 Open-Drain RESET/ RESETB with MRB
n
Applications
l
Portable Electronics
l
Power Supplies
l
Computer Peripherals
l
Data Acquisition Systems
l
Applications using CPUs
l
Consumer Electronics
1
MRB
IN
R1
I1
Delay
R2
GND
V
REF
N1
RESET/
RESETB
Rev. A.01
AME, Inc.
AME8570
n
Pin Description
AME8570AEIT / AME8570AEET
µProcessor
Supervisory
Pin Number
1
2
Pin Name
GND
RESET/RESETB
Ground
Pin Description
This pin can be ordered as RESET or RESETB. Reset is active high.
RESETB is active low. It is also available with an open-drain or push-pull
output.
Positive power supply. A reset is asserted after this voltage drops below
a predetermined level. After V
IN
rises above that level the reset output
remains asserted until the end of the reset timeout period.
3
IN
AME8570AEIU
Pin Number
1
2
Pin Name
GND
RESET/RESETB
Ground
Pin Description
This pin can be ordered as RESET or RESETB. Reset is active high.
RESETB is active low. It is also available with an open-drain or push-pull
output.
Manual RESET. Active low. Pulling this pin low forces a reset. After a
low to high transition reset, remains asserted for exactly one reset timeout
period. This pin is internally pulled high. The pin is floating or tied to V
IN
,
if it is unused.
Positive power supply. A reset is asserted after this voltage drops below
a predetermined level. After V
IN
rises above that level the reset output
remains asserted until the end of the reset timeout period.
3
MRB
4
IN
3
Rev. A.01
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