AME8500 Datasheet, PDF (1/14 Pages) Analog Microelectronics – Micropower uP Reset Family

AME, Inc.
AME8500 / 8501
µProcessor Supervisory
n General Description
The AME8500 family allows the user to customize the
CPU reset function without any external components.
The user has a large choice of reset voltage thresholds,
reset time intervals, and output driver configurations, all
of which are preset at the factory. Each wafer is trimmed
to the customer's specifications.
n Typical Operating Circuit
2
V_CC
AME8500
*
V_CC
Processor
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 for supply voltages greater than 1V.
RESET / RESET
GND
3
RESET
Input
GND
Note: * External pull-up resistor is required if open-
drain output is used. 10 kΩ is recommended.
The AME8501 includes all the above functionality plus
an overtemperature shutdown function. When the ambi-
ent temperature exceeds 80^oC a reset is asserted and
remains asserted until the temperature falls below 60^oC.
Space saving SOT23 packages and micropower qui-
escent current (<3.0µA) make this family a natural for
portable battery powered equipment.
n Features
l Small packages: SOT-23, SOT-89
l 11 voltage threshold options
l Tight voltage threshold tolerance ---±1.50%
l 5 reset interval options
l 4 output configuration options
l Wide temperature range -------- -40^oC to 85^oC
l Low temperature coefficient --- 100ppm/^oC(max)
l Low quiescent current < 3.0µA
l Thermal shutdown option (AME8501)
n Applications
l Portable electronics
l Power supplies
l Computer peripherals
l Data acquisition systems
l Applications using CPUs
l Consumer electronics
n Block Diagram
AME8500 with Push-Pull RESET
V_DD
R1 ^I1
GND
R2
V_REF
P1
Delay
N1
AME8500 with Push-Pull RESET
V_DD
R1 ^I1
GND
R2
V_REF
P1
Delay
N1
RESET
RESET
1