Diodes Incorporated AP7333-18SAG-7

Overview

AP7333-18SAG-7 from Diodes Incorporated is a 300mA fixed-output (1.8V) low-dropout linear regulator in SOT23 package, featuring 65µA quiescent current, 300mV dropout at full load, 65dB PSRR at 100Hz, and stable operation with 1µF ceramic output capacitor. It serves as a power supply for battery-powered microcontrollers and RF modules in portable electronics.

For engineers reviewing the AP7333-18SAG-7 datasheet, AP7333-18SAG-7 pinout, AP7333-18SAG-7 application, or AP7333-18SAG-7 equivalent, key selection criteria include dropout voltage under 300mA load, thermal shutdown threshold at 140°C, fast 80µs startup time, and compatibility with low-ESR ceramic capacitors without minimum load requirement.

Technical Context

The AP7333-18SAG-7 integrates a PMOS pass element, bandgap reference, error amplifier, and protection circuitry (current limit, short-circuit, thermal shutdown). Its architecture enables ultra-low IQ across 2V–6V input while maintaining regulation during rapid load transients from 0 to 300mA.

It delivers fixed 1.8V output with ±2% accuracy over –40°C to +85°C ambient, supports line regulation of 0.01–0.20%/V, and achieves load regulation within ±0.6% across full 0–300mA range - enabling reliable biasing for low-voltage logic and analog subsystems.

Key Specifications

Pinout & Package

SOT23-3 package (JEDEC TO-236AB), 1.3mm × 2.9mm footprint, 1.1mm height, RoHS-compliant lead-free finish. Pin 1 = IN, Pin 2 = OUT, Pin 3 = GND (top view).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output LDO applications.

Compared with MCP1700-1802E/TO and TPS7A0518PDBVR, the AP7333-18SAG-7 uniquely balances 300mA delivery, 65µA IQ, and 300mV dropout - making it the only option among the three capable of powering GSM baseband ICs while sustaining multi-year battery life in wireless sensors.

Availability

AP7333-18SAG-7 is available at Aetrix Electronics and suitable for wireless sensor nodes, GSM baseband power rails, USB-C peripheral hubs, and industrial HMI controllers requiring stable component supply across automotive-grade temperature ranges and long-lifecycle production programs.

Supply support for AP7333-18SAG-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 AP7333 belongs to Diodes' low-quiescent-current LDO family, engineered specifically for battery-powered portable electronics where extended runtime, fast transient response, and small-footprint packaging are essential design constraints.

FAQ

What is the maximum input voltage for AP7333-18SAG-7?

The absolute maximum input voltage is 7V, but the recommended operating range is 2V to 6V. Exceeding 6V risks violating safe operating area limits even with thermal protection active, and may accelerate parametric drift over lifetime. Operation at 6V is validated for full 300mA output with 1.8V regulation and 300mV dropout margin.

Can AP7333-18SAG-7 operate without an output capacitor?

No - an output capacitor is mandatory for stability. The device is designed to be stable with 1µF to 4.7µF ceramic capacitors (X7R/X5R dielectric, 10–200mΩ ESR). Omitting the output capacitor causes oscillation and unregulated output, potentially damaging downstream logic. No minimum load is required, but output capacitance is non-optional.

Does AP7333-18SAG-7 support adjustable output voltage?

No - it is a fixed-output regulator with factory-trimmed 1.8V. There is no feedback pin or external resistor network option. The AP7333 series offers only factory-set voltages (1.0V to 3.3V in 0.1–0.3V steps); adjustable variants are not part of this product family and require different part numbers such as AP7361 or AP7362.

How does thermal shutdown behave under sustained overload?

At ~140°C junction temperature, the output disables; recovery occurs at ~125°C due to 15°C hysteresis. Under continuous overload (e.g., 300mA at 6V input on minimal copper), the device cycles on/off - limiting average power dissipation but causing output voltage interruption. This behavior protects against permanent damage but requires system-level monitoring to detect regulation loss.