APX803S 3-Pin Microprocessor Reset Circuit: Pinout, Equivalent and Datasheet
3 Terminals Voltage supervisor 1 Channels
The APX803S is used for microprocessor (µP) supervisory circuits to monitor the power supplies in µP and digital systems. The APX803S is available with different reset thresholds suitable for operation with a variety of supply voltages. Low supply current makes the APX803S ideal for use in portable equipment. Furthermore, Huge range of Semiconductors, Capacitors, Resistors and IcS in stock. Welcome RFQ.

What is POWER-ON RESET? What does POWER-ON RESET mean? POWER-ON RESET meaning & explanation
- APX803S Pinout
- APX803S CAD Model
- APX803S Overview
- APX803S Features
- Specifications
- APX803S Functional Block Diagram
- APX803S Equivalent
- APX803S Applications
- APX803S Typical Applications Circuit
- APX803S Package
- APX803S Marking Information
- APX803S Suggested Pad Layout
- APX803S Manufacturer
- Trend Analysis
- Datasheet PDF
APX803S Pinout
The following figure is the diagram of APX803S pinout.

Pinout
APX803S CAD Model
The followings are APX803S Symbol, Footprint, and 3D Model.

PCB Symbol

PCB Footprint

3D Model
APX803S Overview
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 external 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 VCC supply voltage declines below a preset threshold, keeping it asserted for a fixed period of time after VCC has risen above the reset threshold. For the APX803S this period 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 VCC, and the outputs are guaranteed to be in the correct logic state for VCC down to 1V. The APX803S is available with different reset thresholds suitable for operation with a variety of supply voltages. Low supply current makes the APX803S ideal for use in portable equipment. The APX803S is available in two pin out variants of the 3-pin SOT23 package.
This article will introduce APX803S systematically from its features, pinout to its specifications, applications, also including APX803S datasheet and so much more.
APX803S Features
● Precision Monitoring of 2.5V, 3.0V, 3.3V, and 5.0V Power-Supply Voltages
● Fully Specified Over Temperature
● 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 VCC = 1V
● Totally Lead-Free & Fully RoHS Compliant
● Halogen and Antimony Free. “Green” Device
Specifications
- TypeParameter
- Factory Lead Time24 Weeks
- Mounting Type
The "Mounting Type" in electronic components refers to the method used to attach or connect a component to a circuit board or other substrate, such as through-hole, surface-mount, or panel mount.
Surface Mount - Package / Case
refers to the protective housing that encases an electronic component, providing mechanical support, electrical connections, and thermal management.
TO-236-3, SC-59, SOT-23-3 - Surface Mount
having leads that are designed to be soldered on the side of a circuit board that the body of the component is mounted on.
YES - Operating Temperature
The operating temperature is the range of ambient temperature within which a power supply, or any other electrical equipment, operate in. This ranges from a minimum operating temperature, to a peak or maximum operating temperature, outside which, the power supply may fail.
-40°C~85°C TA - Packaging
Semiconductor package is a carrier / shell used to contain and cover one or more semiconductor components or integrated circuits. The material of the shell can be metal, plastic, glass or ceramic.
Tape & Reel (TR) - Published2011
- JESD-609 Code
The "JESD-609 Code" in electronic components refers to a standardized marking code that indicates the lead-free solder composition and finish of electronic components for compliance with environmental regulations.
e3 - Pbfree Code
The "Pbfree Code" parameter in electronic components refers to the code or marking used to indicate that the component is lead-free. Lead (Pb) is a toxic substance that has been widely used in electronic components for many years, but due to environmental concerns, there has been a shift towards lead-free alternatives. The Pbfree Code helps manufacturers and users easily identify components that do not contain lead, ensuring compliance with regulations and promoting environmentally friendly practices. It is important to pay attention to the Pbfree Code when selecting electronic components to ensure they meet the necessary requirements for lead-free applications.
yes - Part Status
Parts can have many statuses as they progress through the configuration, analysis, review, and approval stages.
Active - Moisture Sensitivity Level (MSL)
Moisture Sensitivity Level (MSL) is a standardized rating that indicates the susceptibility of electronic components, particularly semiconductors, to moisture-induced damage during storage and the soldering process, defining the allowable exposure time to ambient conditions before they require special handling or baking to prevent failures
1 (Unlimited) - Number of Terminations3
- ECCN Code
An ECCN (Export Control Classification Number) is an alphanumeric code used by the U.S. Bureau of Industry and Security to identify and categorize electronic components and other dual-use items that may require an export license based on their technical characteristics and potential for military use.
EAR99 - TypeSimple Reset/Power-On Reset
- Terminal Finish
Terminal Finish refers to the surface treatment applied to the terminals or leads of electronic components to enhance their performance and longevity. It can improve solderability, corrosion resistance, and overall reliability of the connection in electronic assemblies. Common finishes include nickel, gold, and tin, each possessing distinct properties suitable for various applications. The choice of terminal finish can significantly impact the durability and effectiveness of electronic devices.
Matte Tin (Sn) - Terminal Position
In electronic components, the term "Terminal Position" refers to the physical location of the connection points on the component where external electrical connections can be made. These connection points, known as terminals, are typically used to attach wires, leads, or other components to the main body of the electronic component. The terminal position is important for ensuring proper connectivity and functionality of the component within a circuit. It is often specified in technical datasheets or component specifications to help designers and engineers understand how to properly integrate the component into their circuit designs.
DUAL - Terminal Form
Occurring at or forming the end of a series, succession, or the like; closing; concluding.
GULL WING - Peak Reflow Temperature (Cel)
Peak Reflow Temperature (Cel) is a parameter that specifies the maximum temperature at which an electronic component can be exposed during the reflow soldering process. Reflow soldering is a common method used to attach electronic components to a circuit board. The Peak Reflow Temperature is crucial because it ensures that the component is not damaged or degraded during the soldering process. Exceeding the specified Peak Reflow Temperature can lead to issues such as component failure, reduced performance, or even permanent damage to the component. It is important for manufacturers and assemblers to adhere to the recommended Peak Reflow Temperature to ensure the reliability and functionality of the electronic components.
NOT SPECIFIED - Number of Functions1
- Time@Peak Reflow Temperature-Max (s)
Time@Peak Reflow Temperature-Max (s) refers to the maximum duration that an electronic component can be exposed to the peak reflow temperature during the soldering process, which is crucial for ensuring reliable solder joint formation without damaging the component.
NOT SPECIFIED - Output
In electronic components, the parameter "Output" typically refers to the signal or data that is produced by the component and sent to another part of the circuit or system. The output can be in the form of voltage, current, frequency, or any other measurable quantity depending on the specific component. The output of a component is often crucial in determining its functionality and how it interacts with other components in the circuit. Understanding the output characteristics of electronic components is essential for designing and troubleshooting electronic circuits effectively.
Open Drain or Open Collector - JESD-30 Code
JESD-30 Code refers to a standardized descriptive designation system established by JEDEC for semiconductor-device packages. This system provides a systematic method for generating designators that convey essential information about the package's physical characteristics, such as size and shape, which aids in component identification and selection. By using JESD-30 codes, manufacturers and engineers can ensure consistency and clarity in the specification of semiconductor packages across various applications and industries.
R-PDSO-G3 - Supply Voltage-Max (Vsup)
The parameter "Supply Voltage-Max (Vsup)" in electronic components refers to the maximum voltage that can be safely applied to the component without causing damage. It is an important specification to consider when designing or using electronic circuits to ensure the component operates within its safe operating limits. Exceeding the maximum supply voltage can lead to overheating, component failure, or even permanent damage. It is crucial to adhere to the specified maximum supply voltage to ensure the reliable and safe operation of the electronic component.
5.5V - Supply Voltage-Min (Vsup)
The parameter "Supply Voltage-Min (Vsup)" in electronic components refers to the minimum voltage level required for the component to operate within its specified performance range. This parameter indicates the lowest voltage that can be safely applied to the component without risking damage or malfunction. It is crucial to ensure that the supply voltage provided to the component meets or exceeds this minimum value to ensure proper functionality and reliability. Failure to adhere to the specified minimum supply voltage may result in erratic behavior, reduced performance, or even permanent damage to the component.
1V - Number of Channels1
- Adjustable Threshold
The "Adjustable Threshold" parameter in electronic components refers to the ability to manually set or modify the threshold level at which a specific function or operation is triggered. This feature allows users to customize the sensitivity or activation point of the component according to their specific requirements or preferences. By adjusting the threshold, users can fine-tune the performance of the component to suit different applications or environmental conditions. This flexibility in threshold adjustment can be particularly useful in various electronic devices and systems where precise control over triggering levels is necessary for optimal functionality.
NO - Reset
The "Reset" parameter in electronic components refers to a function that initializes or sets a device to a predefined state. It is often used to clear any temporary data, errors, or configurations that may have been stored during operation. The reset process can ensure that the device starts from a known good state, allowing for reliable performance in subsequent tasks. This parameter is critical in digital circuits and systems where proper initialization is necessary for correct functioning.
Active Low - Voltage - Threshold
Voltage - Threshold is a parameter in electronic components that refers to the minimum voltage level required to trigger a specific function or operation within the component. It is the critical voltage level at which the component transitions from one state to another, such as turning on or off. This threshold voltage is essential for ensuring the proper functioning of the component and is often specified in the component's datasheet. Understanding the voltage threshold is crucial for designing and troubleshooting electronic circuits to ensure that the component operates within its specified voltage range.
3.08V - Number of Voltages Monitored
Voltage monitoring relays can detect not only under-voltages and over-voltages, but also voltage-related issues such as phase imbalances, phase loss, and phase sequence. Voltage monitoring relays are designed for either single-phase or three-phase systems.
1 - Reset Timeout
The "Reset Timeout" parameter in electronic components refers to the amount of time it takes for a device to reset or return to its default state after a specific event or condition. This parameter is crucial in ensuring the proper functioning and reliability of the component, as it determines how quickly the device can recover from a fault or error situation. A shorter reset timeout typically indicates a faster response time, while a longer reset timeout may allow for more thorough error recovery processes. Designers and engineers must carefully consider the reset timeout value to meet the requirements of the application and ensure optimal performance of the electronic component.
140ms Minimum - Length2.9mm
- RoHS Status
RoHS means “Restriction of Certain Hazardous Substances” in the “Hazardous Substances Directive” in electrical and electronic equipment.
ROHS3 Compliant
APX803S Functional Block Diagram
The following is the Functional Block Diagram of APX803S.

Functional Block Diagram
APX803S Equivalent
| Model number | Manufacturer | Description |
| CAT803TSDI-G | On Semiconductor | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO3, GREEN, MO-203, SC-70, 3PIN |
| CAT803TSDI-GT10 | On Semiconductor | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO3, GREEN, MO-203, SC-70, 3 PIN |
| CAT803TSDI-T3 | On Semiconductor | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO3, GREEN, MO-203, SC-70, 3 PIN |
APX803S Applications
● Computers
● Controllers
● Intelligent Instruments
● Critical µP and µC Power Monitoring
● Portable/Battery Powered Equipment
APX803S Typical Applications Circuit
The following is the Typical Applications Circuit of APX803S.

Typical Applications Circuit
APX803S Package
The following diagrams show the APX803S package.

View A

View B

View C
APX803S Marking Information
The following is the Marking Information of APX803S.

Marking Information
APX803S Suggested Pad Layout
The following diagram shows the APX803S Suggested Pad Layout.

Suggested Pad Layout
APX803S Manufacturer
Diodes Incorporated delivers high-quality semiconductor products to the world's leading companies in the consumer electronics, computing, communications, industrial, and automotive markets. They leverage their expanded product portfolio of discrete, analog, and mixed-signal products and leading-edge packaging technology to meet customers' needs. Their broad range of application-specific solutions and solutions-focused sales, coupled with worldwide operations of 25 sites, including engineering, testing, manufacturing, and customer service, enables us to be a premier provider for high-volume, high-growth markets.
Trend Analysis
Datasheet PDF
- Environmental Information :
- Datasheets :
- PCN Assembly/Origin :
What’s the operating temperature of APX803S?
-40°C~85°C TA.
How many terminations of APX803S?
3 terminations.
What is the essential property of the APX803S?
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 external components and adjustments when used with 5.0V, 3.3V, 3.0V and 2.5V powered circuits.
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Diodes Incorporated
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