Document number: DS39161 Rev. 2 - 2
January 2017
© Diodes Incorporated
3-PIN MICROPROCESSOR RESET CIRCUIT
Description
The APX803S
is used for microprocessor (µP) supervisory circuits to
monitor the power supplies in µP and digital systems. They provide
excellent circuit reliability and low cost by eliminating
components and adjustments when used with 5.0V, 3.3V, 3.0V and
2.5V powered circuits.
These circuits perform a single function: they assert a reset signal on
power up and whenever the V
CC
supply voltage declines below a
preset threshold, keeping
it asserted for a fixed period of time after
V
CC
has risen above the reset threshold. For the APX803S
is a minimum of 1ms while for other APX803S
variants it is at least
140ms. The reset comparator is designed to ignore fast transients on
V
CC
,
and the outputs are guaranteed to be in the correct logic state for
V
CC
down to 1V.
The APX803S
is available with different reset thresholds suitable for
operation with a variety of supply voltages. The APX803S has
open drain active low
output and compliment Diodes
APX809S/810S which have push-
pull output stages. Low supply
current makes the APX803S
ideal for use in portable equipment. The
APX803S is available in two pin out variants of the 3-
package.
Features
• Precision Monitoring of 2.5V, 3.0V, 3.3V, and 5.0V Power-
Voltages
• Fully Specified Over Temperature
• Open-drain
Active Low
• Power-On/Power Supply Glitch Reset Pulse
APX803S00 1.7ms (Typ.)
APX803S05 50ms (Typ.)
APX803S 240ms (Typ.)
• 10µA Supply Current (Typ.)
• Guaranteed Reset Valid to V
CC
= 1V
• Totally Lead-Free & Fully RoHS Compliant (Note 1 & 2)
• Halogen and Antimony Free. “Green” Device (Note 3)
Pin Assignments
(Top View)
1
2
GND
V
CC
APX803S
2
3
RESET
SOT23 (SA Package)
(Top View)
1
2
GND
V
CC
APX803S
2
3
RESET
SOT23 (SR Package)
Applications
• Computers
• Controllers
• Intelligent Instruments
• Critical µP and µC Power Monitoring
• Portable/Battery Powered Equipment
Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"
and Lead-free.
3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.