Diodes Incorporated AP7375-18W5-7

Overview

AP7375-18W5-7 from Diodes Incorporated is a 1.8V fixed-output, wide-input (3–45V), 300mA ultra-low-dropout linear regulator in SOT25 package with 2.1μA quiescent current, 35mV dropout at 10mA, and integrated enable pin rated to 45V. It delivers stable power to microcontrollers and sensors in battery-powered smoke detectors and industrial monitoring systems.

For engineers reviewing the AP7375-18W5-7 datasheet, AP7375-18W5-7 pinout, AP7375-18W5-7 application, or AP7375-18W5-7 equivalent, key selection criteria include input voltage range up to 45V, EN pin tolerance to full VIN, ±2% output accuracy, fast transient response without overshoot, and thermal/short-circuit protection for unregulated supply environments.

Technical Context

The AP7375-18W5-7 employs a PMOS pass transistor architecture enabling true low-dropout operation and high PSRR (85dB @ 1kHz) across its 3–45V input range. Its EN pin accepts up to 45V directly-eliminating external level-shifting circuitry when interfacing with high-voltage rails.

Internal protection includes thermal shutdown at +150°C with +20°C hysteresis and current limiting at 500mA. The device maintains regulation during line transients (e.g., 4.3–12V step) and load steps (10–300mA) with <50mV undershoot/overshoot and no startup overshoot.

Key Specifications

Pinout & Package

SOT25 package (3.0mm × 2.8mm × 1.3mm body, 5-pin, exposed thermal pad). Optimized for thermal dissipation via large PCB copper area connected to EP.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-IQ, wide-input LDO applications.

Compared with AP7375-18W5-7, AP7361-18W5-7 trades current capacity for identical low-power performance in space-constrained designs, while TPS7B8133QDGNRQ1 adds automotive reliability at the cost of reduced input voltage margin and added external component count for EN control.

Availability

AP7375-18W5-7 is available at Aetrix Electronics and suitable for battery-powered equipment, smoke detectors and sensors, microcontroller applications, and home appliances requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for AP7375-18W5-7 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, automotive, and consumer markets.

The AP7375 series belongs to Diodes' ultra-low-IQ LDO portfolio, designed specifically for energy-sensitive applications where wide input range, minimal quiescent consumption, and robust fault protection are mandatory - not optional.

FAQ

What is the minimum input voltage required for regulation at 1.8V output?

The AP7375-18W5-7 requires VIN ≥ VOUT + VDROP(MAX). With a maximum dropout of 360mV at 100mA (per datasheet), regulation is guaranteed above 2.16V. However, the absolute minimum specified VIN is 3.0V per Recommended Operating Conditions - below which internal biasing may fail.

Can the EN pin be left floating?

No. The EN pin has no internal pull-up or pull-down. Leaving it floating risks undefined operation and potential unintended shutdown. It must be actively driven high (≥1V) to enable or low (≤0.4V) to disable - or tied to VIN via a resistor if always-on operation is required.

Is the exposed pad (EP) electrically connected internally?

No. The exposed pad is thermally conductive only and not bonded to any internal die node. It must be soldered to a PCB copper area connected to GND for optimal thermal performance, but should never serve as the sole GND connection path for the device.

Does AP7375-18W5-7 require an input capacitor?

Yes. A minimum 1μF ceramic capacitor (X7R/X5R) is required between VIN and GND, placed as close as possible to the pins. This stabilizes the input rail against switching noise and prevents oscillation - especially critical when sourced from high-impedance or long-trace supplies.