Diodes Incorporated APX809-23SRG-7

Overview

APX809-23SRG-7 from Diodes Incorporated is a 3-pin SOT23 microprocessor supervisory IC that monitors 2.3V power supplies and asserts an active-low reset signal during brownout or power-up conditions. It provides a guaranteed 200ms minimum reset timeout, operates down to VCC = 1V, draws only 30µA typical supply current, and features push-pull output for direct µP reset pin drive in embedded controllers and portable equipment.

For engineers reviewing the APX809-23SRG-7 datasheet, APX809-23SRG-7 pinout, APX809-23SRG-7 application, or APX809-23SRG-7 equivalent, key selection criteria include reset threshold accuracy (2.25V ±0.05V), temperature-stable timeout (140–280ms), low-VCC validity (1V), push-pull drive capability, and SOT23 footprint compatibility with space-constrained PCB layouts.

Technical Context

The APX809-23SRG-7 implements a precision voltage comparator with internal reference and fixed delay timer to generate a clean, glitch-immune reset pulse. Its reset assertion is triggered when VCC falls below 2.25V (±0.05V over −40°C to +85°C), and the reset remains active for ≥240ms after VCC rises above threshold.

Designed for single-function supervision, it requires no external components, ignores fast VCC transients, and guarantees correct logic state on RESET even as VCC drops to 1V - enabling reliable boot sequencing in battery-powered systems where supply collapse is gradual.

Key Specifications

Pinout & Package

SOT23-3 (SR package) surface-mount package with 2.4mm × 1.3mm footprint, 0.95mm height, and standard JEDEC-compliant pad layout for reflow compatibility.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD2T and TPS3808G125DBVR, the APX809-23SRG-7 delivers optimal balance of threshold accuracy, guaranteed 200ms timeout, push-pull drive, and zero-component simplicity - making it ideal for cost-sensitive, space-constrained industrial and portable designs where fixed supervision suffices.

Availability

APX809-23SRG-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 support, and RoHS-compliant sourcing.

Supply support for APX809-23SRG-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, cost-optimized components for industrial, computing, and consumer markets.

The APX809/810 series was designed specifically for microprocessor power-supply supervision - delivering precision reset thresholds, minimal external dependencies, and robust operation across wide temperature and voltage ranges in embedded control systems.

FAQ

What is the exact reset threshold voltage for APX809-23SRG-7 and how does it vary with temperature?

The APX809-23SRG-7 has a nominal reset threshold of 2.25V, with a guaranteed range of 2.20V to 2.30V over −40°C to +85°C ambient temperature. Its tempco is ≤30ppm/°C, meaning threshold drift is bounded to ±0.01V across the full operating range - critical for deterministic reset behavior in thermally variable environments like factory automation enclosures.

Does APX809-23SRG-7 require an external pull-up resistor on the RESET pin?

No. The APX809-23SRG-7 features a push-pull output stage, so the RESET pin actively drives low during reset and high when inactive. No external pull-up is needed - simplifying layout, reducing component count, and eliminating resistor tolerance and temperature drift effects on reset timing.

Can APX809-23SRG-7 operate reliably with a 1.8V supply rail?

Yes. While its 2.25V threshold targets 2.3V/2.5V systems, the device functions correctly with VCC as low as 1.0V and up to 5.5V. However, it will not assert reset for a 1.8V rail unless that rail dips below 2.25V - so it is unsuitable for supervising 1.8V-only systems but fully compatible as a secondary supervisor in mixed-voltage designs.

Is APX809-23SRG-7 pin-compatible with other members of the APX809/810 family?

Yes - all APX809/810 variants share identical SOT23-3 (SR or SA) pinout: Pin 1 = VCC, Pin 2 = GND, Pin 3 = RESET. This allows drop-in replacement across threshold voltages (e.g., -23, -26, -29) and output polarity (APX809 vs. APX810), provided the application requires matching reset polarity and timing behavior.