Diodes Incorporated APX803-40SAG-7

Overview

APX803-40SAG-7 from Diodes Incorporated is a 3-pin SOT23 microprocessor reset supervisor IC with 4.00 V ±0.06 V precision reset threshold, open-drain active-low RESET output, 200 ms typical reset timeout (≥140 ms over temperature), and guaranteed operation down to VCC = 1.0 V. It monitors 5 V supply rails in embedded controllers and portable systems, asserting reset during power-up, brownout, or supply glitches.

For engineers reviewing the APX803-40SAG-7 datasheet, APX803-40SAG-7 pinout, APX803-40SAG-7 application, or APX803-40SAG-7 equivalent, key selection criteria include reset threshold accuracy (±0.06 V), minimum timeout duration (140 ms), open-drain drive capability (3.5 mA sink at 0.4 V), ultra-low 30 µA supply current, and guaranteed reset validity down to 1.0 V VCC.

Technical Context

The APX803-40SAG-7 implements a precision bandgap-based voltage comparator with 40 mV hysteresis and internal oscillator-controlled delay timer. Its reset assertion logic responds to VCC falling below 4.00 V and holds RESET low for ≥140 ms after VCC rises above threshold - independent of VCC slew rate up to 100 V/µs.

Designed for single-supply monitoring, it features an open-drain N-channel output stage capable of sinking 3.5 mA at VOL ≤ 0.4 V (VCC = VTH − 0.2 V), with leakage <1 µA when high. The device operates across −40°C to +85°C ambient and maintains reset validity down to VCC = 1.0 V before entering high-impedance state.

Key Specifications

Pinout & Package

APX803-40SAG-7 is housed in a RoHS-compliant, halogen-free SOT23-3 (SA package) with 2.4 mm × 1.3 mm footprint and 0.95 mm height. Thermal resistance θJA = 201°C/W on standard FR-4 board.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809SEUR+T and TPS3808G33DBVR, the APX803-40SAG-7 provides optimal trade-off between 5 V rail compatibility, open-drain flexibility for multi-voltage systems, and proven industrial temperature stability - without requiring external components or configuration.

Availability

APX803-40SAG-7 is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical monitors, and smart energy meters requiring stable component supply, long-lifecycle assurance, and RoHS-compliant sourcing.

Supply support for APX803-40SAG-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 integrated circuits, specializing in high-reliability power management, signal integrity, and protection devices for industrial, computing, and consumer markets.

The APX803 series belongs to Diodes' precision voltage supervisor product line, engineered specifically for cost-sensitive, space-constrained microprocessor reset applications where accuracy, low power, and robust transient immunity are mandatory.

FAQ

What is the exact reset threshold voltage and tolerance for APX803-40SAG-7?

The APX803-40SAG-7 has a nominal reset threshold of 4.00 V, with a guaranteed range of 3.94 V to 4.06 V at +25°C. Over the full operating temperature range (−40°C to +85°C), the threshold remains within ±12 mV of nominal due to its 30 ppm/°C tempco, ensuring consistent 5 V rail monitoring performance.

Does APX803-40SAG-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 (typically the same VCC rail being monitored or another system rail). Recommended value is 10 kΩ to 100 kΩ; lower values improve noise immunity but increase static current draw.

Can APX803-40SAG-7 operate reliably below 1.1 V VCC?

No - the device guarantees correct reset assertion only down to VCC = 1.0 V. Below that, the internal circuitry ceases to function and RESET enters high-impedance state. For applications requiring reset validity below 1.0 V, a different supervisor family (e.g., APX811) must be selected.

Is APX803-40SAG-7 compatible with bidirectional microcontroller reset pins?

Yes - its open-drain RESET output allows direct connection to bidirectional reset pins (e.g., Motorola 68HC11, STM32L0x) using a single shared pull-up resistor. Either the APX803 or the µC can assert reset, enabling coordinated system-level recovery without additional logic.