Diodes Incorporated APX803S05-40SR-7

Overview

APX803S05-40SR-7 from Diodes Incorporated is a 3-pin SOT23 open-drain microprocessor reset supervisor IC designed for 4.0V supply monitoring in embedded systems. It asserts an active-low RESET signal during power-up, brownout, or VCC drop below 4.00V threshold and holds it for 50ms (typical) after VCC recovers. Key specs: 4.00V reset threshold, 50ms timeout, 10µA supply current, guaranteed operation down to VCC = 1V, and −40°C to +85°C operating range - used in portable controllers and battery-powered µP systems.

For engineers reviewing the APX803S05-40SR-7 datasheet, APX803S05-40SR-7 pinout, APX803S05-40SR-7 application, or APX803S05-40SR-7 equivalent, this page delivers verified functional identity, exact SOT23-SR pin mapping, confirmed 4.00V/50ms timing behavior, and validated alternatives for 4V-supervised reset design.

Technical Context

The APX803S05-40SR-7 implements a precision voltage comparator with hysteresis and a fixed 50ms monostable timeout circuit. Its reset assertion logic is triggered when VCC falls below 4.00V (±60mV), and the internal timer restarts on every threshold crossing, ensuring robust immunity to supply transients up to 100V/µs dVCC/dt.

It features an open-drain RESET output capable of sinking ≥1.2mA at 0.3V low-level voltage while operating from VCC as low as 1.0V. The device ignores fast VCC glitches and maintains valid logic state across full industrial temperature range without external components.

Key Specifications

Pinout & Package

APX803S05-40SR-7 is housed in a RoHS-compliant SOT23-3 (SR package) with gull-wing leads, 2.9mm × 1.3mm footprint, and 0.95mm height - optimized for high-density PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor reset supervision applications.

Compared with APX803S05-40SR-7, the APX809S variant offers integrated drive but sacrifices bus-sharing capability, while the MAX809 provides longer timing margin at the cost of higher current and inflexible output structure - making the APX803S05-40SR-7 optimal for compact, low-power, multi-device reset networks.

Availability

APX803S05-40SR-7 is available at Aetrix Electronics and suitable for industrial controllers, portable medical devices, automotive body electronics, and smart energy meters requiring stable component supply with guaranteed long-term availability.

Supply support for APX803S05-40SR-7 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and protection solutions for industrial, computing, and automotive markets.

The APX803S series belongs to Diodes' µP supervisor product line, engineered specifically for cost-sensitive, space-constrained embedded systems requiring precise, low-quiescent-current reset functionality across multiple supply voltages.

FAQ

What is the exact reset threshold voltage and tolerance for APX803S05-40SR-7?

The APX803S05-40SR-7 has a nominal reset threshold of 4.00V, with a guaranteed range of 3.94V to 4.06V at +25°C. Over the full −40°C to +85°C operating temperature range, the threshold variation is limited to ±30ppm/°C, resulting in total deviation under ±12mV - sufficient for stable 4.0V rail supervision without recalibration.

Can APX803S05-40SR-7 drive a reset line shared among multiple microcontrollers?

Yes - its open-drain RESET output supports wired-OR configuration. When multiple APX803S05-40SR-7 devices (or other open-drain reset sources) share a common RESET net with a single pull-up resistor, any device asserting low will hold the entire bus in reset. This enables coordinated system-level reset across distributed subsystems without additional logic.

Does APX803S05-40SR-7 require external components to function?

No external components are required. The device integrates the voltage reference, comparator, timer, and output driver in a single SOT23-3 package. Only a pull-up resistor on the RESET pin is needed for proper logic-level translation - no capacitors, resistors, or trimming networks are necessary for basic 4.0V supervision with 50ms timeout.

How does APX803S05-40SR-7 behave when VCC drops below 1.0V?

Below VCC = 1.0V, the internal circuitry ceases operation and the RESET pin transitions to high-impedance (open-circuit). It no longer actively drives low or sources leakage current. In most systems, this is acceptable because µPs and supporting logic are non-functional below 1.0V, and external pull-up ensures defined logic-high state during deep undervoltage or complete power loss.