Diodes Incorporated AP7354D-18W5-7

Overview

AP7354D-18W5-7 from Diodes Incorporated is a 1.8V fixed-output, 150mA ultra-low quiescent current LDO regulator in SOT25 package with integrated enable control and active output discharge. It operates from 2.0V to 5.5V input, delivers ±1% output accuracy at +25°C, and draws only 0.25µA quiescent current-enabling multi-year battery life in wearable sensors and IoT edge nodes.

For engineers reviewing the AP7354D-18W5-7 datasheet, AP7354D-18W5-7 pinout, AP7354D-18W5-7 application, or AP7354D-18W5-7 equivalent, key selection criteria include dropout voltage at 150mA (0.33V typ), EN logic thresholds (0.4V low / 1.0V high), active discharge resistance (35Ω), thermal resistance (162°C/W), and compatibility with 0.1µF ceramic input/output capacitors.

Technical Context

The AP7354D-18W5-7 integrates a precision voltage reference, error amplifier, current-limit circuit, and enable-controlled pass transistor in a single monolithic IC. Its feedback loop maintains regulation across load steps (1mA–150mA) and line variations (2.0V–5.5V), with built-in short-circuit protection limiting output current to 60mA under fault conditions.

Unlike non-discharge variants, this D-suffix version includes an internal NMOS discharge switch between VOUT and GND, activated when EN is pulled low. This ensures rapid VOUT decay (<1ms typical) to prevent back-powering downstream circuitry-a critical requirement in power-sequenced systems and battery-powered devices with multiple rail domains.

Key Specifications

Pinout & Package

SOT25 package: 5-pin surface-mount plastic package with exposed pad (not electrically connected); dimensions 2.80mm × 2.90mm × 1.10mm; RoHS-compliant matte tin plating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-1802E/TO and XC6210B182MR-G, AP7354D-18W5-7 uniquely combines sub-µA quiescent current, integrated discharge, and low dropout in a standard SOT25 footprint-making it optimal for space-constrained, battery-sensitive, and power-sequenced designs where reliability and minimal external components are essential.

Availability

AP7354D-18W5-7 is available at Aetrix Electronics and suitable for wearable electronics, IoT sensor modules, and wireless communication devices requiring stable component supply with long-term manufacturability and consistent parametric performance.

Supply support for AP7354D-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 semiconductor company specializing in discrete, analog, and mixed-signal solutions for power management, signal integrity, and connectivity applications.

The AP7354 series belongs to Diodes' ultra-low-I_Q LDO portfolio, engineered specifically for energy-harvesting and battery-powered edge devices where runtime, size, and power sequencing reliability are primary design constraints.

FAQ

What is the minimum input voltage required to maintain 1.8V output at 150mA?

The AP7354D-18W5-7 requires VIN ≥ 2.13V to sustain 1.8V output at 150mA, based on its typical 0.33V dropout voltage. At worst-case 0.60V dropout (per datasheet max), VIN must be ≥ 2.4V. Operation below 2.0V input is outside specified limits and may cause regulation loss or instability.

Can the EN pin be left floating?

No. The EN pin must never be left floating-it must be actively driven high (≥1.0V) to enable regulation or low (≤0.4V) to enter shutdown. Floating EN causes undefined output behavior and potential shoot-through current. If unused, tie EN directly to VIN using a low-impedance connection.

Is an output capacitor mandatory, and what type is recommended?

Yes, a minimum 0.1µF ceramic capacitor (X5R or X7R dielectric) is mandatory on VOUT for stability and transient response. Tantalum or aluminum electrolytic capacitors are not recommended due to higher ESR, which can induce oscillation. Place the capacitor within 2mm of VOUT and GND pins with short, wide traces.

How does the active output discharge function interact with external loads?

When EN is pulled low, the internal 35Ω NMOS switch connects VOUT to GND, discharging any attached capacitance. This prevents back-powering of upstream regulators or leakage into disabled circuit blocks. Loads drawing current during discharge (e.g., pull-up resistors) will experience faster VOUT decay but must not exceed 60mA sink current to avoid damage.