Diodes Incorporated APX803S00-44SR-7

Overview

APX803S00-44SR-7 from Diodes Incorporated is a 3-pin SOT23 open-drain microprocessor reset supervisor IC designed for 4.38 V ±0.07 V supply monitoring with 1.7 ms typical reset timeout, guaranteed reset validity down to VCC = 1 V, and 10 µA typical supply current. It provides power-on and brownout reset assertion in portable, battery-powered, and industrial embedded systems.

For engineers reviewing the APX803S00-44SR-7 datasheet, APX803S00-44SR-7 pinout, APX803S00-44SR-7 application, or APX803S00-44SR-7 equivalent, key selection criteria include precise 4.38 V threshold tolerance (±0.07 V), 1.7 ms fixed timeout, open-drain active-low output compatibility with bidirectional µP reset pins, and operation across –40°C to +85°C.

Technical Context

The APX803S00-44SR-7 integrates a precision voltage comparator with 30 ppm/°C tempco and an internal timer that initiates only after VCC rises above the 4.38 V threshold. Its open-drain RESET output requires an external pull-up and sinks up to 3.5 mA at 0.4 V while maintaining logic-low state down to VCC = 1 V.

It rejects fast transients on VCC via inherent hysteresis and dVCC/dt immunity up to 100 V/µs. The device asserts reset during power-up, brownout (VCC < 4.31 V), and power-down, holding RESET low for ≥1 ms after VCC exceeds 4.45 V - independent of supply ramp rate or load.

Key Specifications

Pinout & Package

APX803S00-44SR-7 is housed in a RoHS-compliant, halogen-free SOT23-3 (SR package) with gull-wing leads and 2.9 mm × 1.3 mm footprint. Thermal resistance is θJA = 232°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809SEUR+T and TPS3808G01DBVR, APX803S00-44SR-7 delivers the exact 4.38 V threshold with minimal 1.7 ms timeout and zero external components - making it optimal for space-constrained, low-power, fast-boot embedded designs where deterministic short-duration reset is critical.

Availability

APX803S00-44SR-7 is available at Aetrix Electronics and suitable for industrial PLC I/O modules, portable medical monitors, and smart energy meters requiring stable component supply, long-term lifecycle support, and guaranteed RoHS/Green compliance.

Supply support for APX803S00-44SR-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 devices for industrial, computing, and consumer markets.

The APX803S series belongs to Diodes' µP supervisor product line, engineered specifically for cost-sensitive, low-power embedded systems requiring precision voltage monitoring and deterministic reset timing without external components.

FAQ

What is the exact reset threshold voltage for APX803S00-44SR-7?

The APX803S00-44SR-7 has a guaranteed reset threshold range of 4.31 V (minimum) to 4.45 V (maximum) at +25°C, with a typical value of 4.38 V. This specification is fully characterized over –40°C to +85°C with a tempco of 30 ppm/°C, ensuring consistent performance across industrial temperature ranges.

Does APX803S00-44SR-7 require an external pull-up resistor on the RESET pin?

Yes - the RESET pin is open-drain active-low and requires an external pull-up resistor to a valid logic-high voltage rail (e.g., VCC or another supply). Typical values range from 10 kΩ to 100 kΩ depending on bus capacitance and sink current requirements; Diodes recommends ≤4.7 kΩ for 3.5 mA sink capability at 0.4 V.

Can APX803S00-44SR-7 operate reliably below 2.0 V supply voltage?

Yes - the device guarantees valid reset assertion down to VCC = 1.0 V. Below 1.0 V, the internal circuitry ceases to function and RESET becomes high-impedance. This behavior is intentional and documented in the absolute maximum ratings and functional description sections of DS39161 Rev. 2–2.

How does the 1.7 ms reset timeout differ from other APX803S variants?

The "00" suffix denotes the shortest timeout option: 1 ms (min), 1.7 ms (typ), 3.3 ms (max). In contrast, standard APX803S-XX variants offer 140–280 ms, and "05" variants provide 20–70 ms. This makes the 00 variant ideal for µPs with fast boot sequences (<5 ms) where extended reset hold would delay system readiness.