Diodes Incorporated AP431AQG-7

Overview

AP431AQG-7 from Diodes Incorporated is a 3-terminal adjustable precision shunt regulator with 2.495V ±0.5% reference voltage, 0.2Ω dynamic output impedance, and 200mA sink current capability. It operates from 2.495V to 36V output via external resistor divider and is used in feedback loops of isolated DC-DC converters, voltage monitors, and current sources.

For engineers reviewing the AP431AQG-7 datasheet, AP431AQG-7 pinout, AP431AQG-7 application, or AP431AQG-7 equivalent, key selection criteria include reference tolerance (±0.5%), cathode current range (0.19–250mA), temperature coefficient (30ppm/°C), and SOT25 package compatibility with space-constrained power supply designs.

Technical Context

The AP431AQG-7 implements a bandgap-based precision reference with active error amplifier and output stage, enabling sharp turn-on response and low-output-impedance regulation across its full 2.495–36V programmable range. Its internal architecture supports stable operation with load capacitances up to 100µF when properly compensated per Figure 8 stability boundary curves.

It functions as a 3-terminal programmable shunt element where cathode voltage is regulated by feedback through REF and ANODE terminals; the device draws only 1.4–3.5µA reference input current and maintains regulation down to 0.19mA minimum cathode current - critical for low-power bias networks and precision current sinks.

Key Specifications

Pinout & Package

SOT25 package: 5-pin, surface-mount, RoHS-compliant, green molding compound; footprint compatible with standard SOT-23-5 land patterns (Z=3.20mm, X=0.55mm, Y=0.80mm per AP02001).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar adjustable shunt regulator applications.

Compared with TL431BIDBZR and AS431AT-E1, AP431AQG-7 offers lower dynamic impedance (0.2Ω vs. 0.35Ω/0.25Ω) and wider cathode voltage range (down to 2.495V), enabling tighter regulation in low-headroom 3.3V or 5V systems without sacrificing transient response.

Availability

AP431AQG-7 is available at Aetrix Electronics and suitable for isolated DC-DC converter feedback, precision current sinking, and overvoltage protection circuits requiring stable component supply across industrial, telecom, and consumer power applications.

Supply support for AP431AQG-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 power management, signal integrity, and protection devices for industrial, computing, and consumer markets.

The AP431/AP431A product line delivers precision shunt regulation for cost-sensitive, space-constrained power supply feedback and monitoring applications - designed to replace Zener diodes with superior stability and programmability.

FAQ

What is the minimum cathode current required for regulation in AP431AQG-7?

The AP431AQG-7 requires a minimum cathode current of 0.19mA (190µA) to maintain regulation, as specified in the Electrical Characteristics table under IKA(MIN). This value is measured at V_KA = V_REF and ensures stable reference operation even in ultra-low-power bias networks.

Can AP431AQG-7 be used in place of TL431 in existing designs?

Yes, AP431AQG-7 is pin-compatible with TL431 in SOT25 packages and shares identical functional pinout (Cathode, Anode, REF). However, its lower 2.495V reference and 0.2Ω output impedance may require minor resistor-divider recalibration and reduced compensation capacitance for optimal stability.

Does AP431AQG-7 support operation above 85°C ambient temperature?

No - the AP431AQG-7 is rated for −20°C to +85°C operating temperature per Absolute Maximum Ratings. Exceeding +85°C ambient risks exceeding the 150°C maximum junction temperature, especially at high cathode currents; thermal derating must be applied per power dissipation limits in SO-8 or SOT89 packages.

How does the 30ppm/°C temperature coefficient impact long-term voltage accuracy?

Over the full −20°C to +85°C range (105°C delta), the 30ppm/°C coefficient contributes ≤±3.15mV (0.00315 × 105 × 2.495V) reference drift. Combined with initial ±0.5% tolerance, total worst-case error remains within ±1.5% - sufficient for most industrial power supply specifications without trimming.