APX803-46SAG-7 Diodes Inc, APX803-46SAG-7 Datasheet - Page 5

• Manufacturer Part Number: APX803-46SAG-7
• Description: IC MPU RESET CIRC 4.63V SOT23-3
• Manufacturer: Diodes Inc
• Type: Simple Reset/Power-On Resetr

Specifications of APX803-46SAG-7

• Number Of Voltages Monitored: 1
• Output: Open Drain or Open Collector
• Reset: Active Low
• Reset Timeout: 140 ms Minimum
• Voltage - Threshold: 4.63V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-3, TO-236-3, Micro3™, SSD3, SST3
• Overvoltage Threshold: 4.63 V
• Power-up Reset Delay (typ): 200 ms
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 1.1 V
• Supply Current (typ): 20 uA
• Maximum Power Dissipation: 400 mW
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Output Type: Open Collector / Drain
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: APX803-46SAG-7DITR

Functional Description
Microprocessors (µPs) and microcontrollers (µC) have a reset
input to ensure that it starts up in a known state. The APX803
drive the µP’s reset input to prevent code-execution errors during
power-up, power-down, or brownout conditions. They assert a
reset signal whenever the V
preset threshold, keeping it asserted for at least 140ms after V
has risen above the reset threshold. The APX803 has an
open-drain output stage.
Ensuring a Valid Reset Output
Down to V
exceeds the reset threshold, an internal timer keeps
low for the reset timeout period; after this interval,
goes high. If a brownout condition occurs (V
V
zero, and
V
low for the reset timeout period.
When V
longer sinks current — it becomes an open circuit. Therefore,
high-impedance CMOS logic inputs connected to
Block Diagram
APX803 Rev. 1
Document number: DS32132 Rev. 1 – 2
RESET
RESET
CC
CC
goes below the reset threshold, the internal timer resets to
returns above the reset threshold, and
CC
reset threshold),
is guaranteed to be a logic low for V
CC
falls below 1V, the APX803
RESET
= 0
V
REF
goes low. The internal timer starts after
CC
RESET
supply voltage declines below a
goes low. Any time
RESET
CC
RESET
CC
> 1V. Once V
Delay Circuit
dips below the
RESET
www.diodes.com
output no
RESET
RESET
remains
can
5 of 10
CC
CC
3-PIN MICROPROCESSOR RESET CIRCUIT
drift to undetermined voltages.
This presents no problem in most applications since most µP and
other circuitry is inoperative with V
Interfacing to µP with Bidirectional Reset Pins
Since the RESET output on the APX803 is open drain, this
device interfaces easily with μP/µC that have bidirectional reset
pins, such as the Motorola 68HC11.
Connecting the μP supervisor’s RESET output directly to the
microcontroller’s (μC’s) RESET pin with a single pull-up resistor
allows either device to assert reset.
Supervising and monitoring Multiple Supplies
Generally, the pull-up resistor connected to the APX803 will
connect to the supply voltage that is being monitored at the IC’s
V
open-drain output to level-shift from the monitored supply to reset
the µP powered by a different supply voltage or monitor multiple
supplies that will be fed into 1 µC/µP reset input.
CC
pin. However, some systems may use the APX803
Driver
CC
below 1V.
©
APX803
Diodes Incorporated
MARCH 2010
/ RESET
RESET