Diodes Incorporated AP432SAG-7

Overview

AP432SAG-7 from Diodes Incorporated is a 3-terminal adjustable precision shunt regulator with ±1% reference voltage tolerance (1.24 V), 200 mA sink current capability, and 0.2 Ω dynamic output impedance. It operates over −20°C to +85°C and sets programmable output voltages from 1.24 V to 20 V using two external resistors-replacing Zener diodes in feedback loops of AC/DC adapters, LED drivers, and voltage monitors.

For engineers reviewing the AP432SAG-7 datasheet, AP432SAG-7 pinout, AP432SAG-7 application, or AP432SAG-7 equivalent, key selection criteria include reference accuracy, cathode current headroom, temperature coefficient (30 ppm/°C), minimum regulation current (150 µA), and SOT23 package thermal performance in space-constrained power supplies.

Technical Context

The AP432SAG-7 implements an internal bandgap reference and high-gain error amplifier driving an active NPN output stage, enabling sharp turn-on and low-output-impedance regulation. Its architecture supports stable operation with capacitive loads up to 100 µF when properly biased via external resistor divider networks.

It functions as a 2-terminal programmable voltage reference in parallel with load, where cathode current varies inversely with input voltage changes-enabling precise overvoltage protection, current limiting, and delay timing circuits without external op-amps or comparators.

Key Specifications

Pinout & Package

AP432SAG-7 is housed in a RoHS-compliant, lead-free SOT23-3 package (JEDEC TO-236AB), with 1.3 mm × 2.9 mm footprint and 1.1 mm max height. Thermal resistance θ_JA is 270°C/W, supporting 400 mW power dissipation at +25°C ambient.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AZ431L and TL431BIDBZR, AP432SAG-7 delivers higher sink current (200 mA vs. ≤100 mA) and lower output impedance (0.2 Ω vs. ≥0.35 Ω) in a thermally efficient SOT23 package-making it optimal for space-constrained, medium-power regulation where dynamic stability and thermal headroom are critical.

Availability

AP432SAG-7 is available at Aetrix Electronics and suitable for AC/DC adapters, LED drivers, and overvoltage protection circuits requiring stable component supply, consistent parametric performance, and long-term manufacturing continuity.

Supply support for AP432SAG-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 consumer markets.

The AP432 series belongs to Diodes' precision shunt regulator product line, engineered for cost-effective replacement of Zener diodes in feedback, protection, and current-setting applications across commercial and extended-temperature environments.

FAQ

What is the minimum cathode current required for regulation in AP432SAG-7?

The AP432SAG-7 requires a minimum cathode current of 150 µA to maintain regulation, verified across −20°C to +85°C. This low threshold enables stable operation in ultra-low-power standby modes and battery-backed monitoring circuits where total system current must remain below 200 µA.

Can AP432SAG-7 replace a standard Zener diode directly in existing designs?

Yes-AP432SAG-7 can directly replace Zener diodes rated 1.24 V to 20 V when used with two external resistors forming a voltage divider. Unlike Zeners, it provides ±1% initial tolerance, 30 ppm/°C tempco, and active turn-on, eliminating voltage drift and soft knee behavior seen in passive Zener devices.

What is the maximum capacitive load the AP432SAG-7 can drive without oscillation?

Stability testing shows AP432SAG-7 remains stable with up to 100 µF capacitive load when biased at 10 mA cathode current and operating at 25°C. For loads >10 µF, a series resistor (≤10 Ω) between cathode and capacitor is recommended to damp high-frequency peaking per Figure 5 in DS31003 Rev. 19.

Does AP432SAG-7 support operation above 85°C ambient temperature?

No-the AP432SAG-7 is specified for −20°C to +85°C operating ambient temperature. At 85°C, its maximum allowable power dissipation drops to ~240 mW due to thermal derating. For higher-temperature environments, Diodes recommends the AP432Y (SOT89-3) variant with improved thermal resistance (θ_JA = 180°C/W).