AME
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 ( < 3.0µA ) make this family a natural for
portable battery powered equipment.
GND
µProcessor
Supervisory
n
Functional Block Diagram
AME8570 Push-Pull RESET/ RESETB
V
IN
R1
I1
Delay
R2
GND
V
REF
N1
P1
RESET/
RESETB
AME8570 Open-Drain RESETB
V
IN
R1
I1
Delay
RESET/
RESETB
N1
R2
V
REF
n
Features
l
Small Packages : SC-70, SOT-23, SOT-143
l
Tight Voltage Threshold Tolerance :
± 1.50%
l
Wide Temperature Range : -40
O
C to +85
O
C
l
Low Quiescent Current < 3.0
µA
l
Manual Reset Input Option
l
Green Products Meet RoHS Standards
AME8570 Push-Pull RESET/ RESETB with MRB
MRB
V
IN
R1
I1
Delay
R2
GND
V
REF
N1
P1
RESET/
RESETB
AME8570 Open-Drain RESETB with MRB
MRB
n
Applications
l
Portable Electronics
l
Power Supplies
l
Computer Peripherals
l
Data Acquisition Systems
l
Applications using CPUs
l
Consumer Electronics
Rev.C.02
V
IN
R1
I1
Delay
R2
GND
V
REF
N1
RESET/
RESETB
1
AME
AME8570
n
Pin Configuration
SOT-143
Top View
4
3
µProcessor
Supervisory
AME8570AE4U
1. GND
2. RESET/RESETB
AME8570
3. MRB
4. IN
1
2
* Die Attach:
Conductive Epoxy
n
Pin Description
AME8570AEET/AME8570BEET/AME8570CEET
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.
IN
Rev.C.02
3
AME
AME8570
n
Pin Description
AME8570AEIU / AME8570AE4U
µProcessor
Supervisory
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.
MRB
IN
4
Rev. C.02
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