Diodes Incorporated AP7347D-18FDZW-7B

Overview

AP7347D-18FDZW-7B from Diodes Incorporated is a 500mA, 1.8V fixed-output low-dropout regulator with ±1% output accuracy, 75dB PSRR at 1kHz, 60µV_rms output noise (10Hz–100kHz), and 60µA quiescent current. It features enable control, thermal shutdown, short-circuit protection, and auto-discharge functionality. Designed for noise-sensitive automotive electronics, it operates across –40°C to +125°C ambient temperature with input voltage range 1.7V–5.5V.

For engineers reviewing the AP7347D-18FDZW-7B datasheet, AP7347D-18FDZW-7B pinout, AP7347D-18FDZW-7B application, or AP7347D-18FDZW-7B equivalent, key selection criteria include its W-DFN2020-6 (SWP) wettable flank package, 0.32V typical dropout at 500mA (for V_OUT = 1.8V), EN logic thresholds (V_IL ≤ 0.5V, V_IH ≥ 1.25V), and guaranteed automotive-grade reliability per AP7347DQ qualification.

Technical Context

The AP7347D-18FDZW-7B integrates a CMOS-based LDO architecture with internal voltage reference, error amplifier, current-limit circuit, and NMOS pass transistor featuring auto-discharge capability via integrated 30Ω on-resistance when disabled. Its feedback loop is internally compensated for stability with 1µF ceramic output capacitors.

It supports fast enable/disable transitions (typ. 40µs turn-off, 200µs turn-on), delivers regulated 1.8V output under load transients up to 500mA, and maintains regulation during line transients across its full 1.7V–5.5V input range - critical for battery-powered and start-stop automotive systems.

Key Specifications

Pinout & Package

AP7347D-18FDZW-7B uses the W-DFN2020-6 (SWP) Type A1 wettable flank package (2.0mm × 2.0mm × 0.75mm), optimized for automated optical inspection (AOI) and high-density PCB layouts. The exposed pad (EP) must be connected to GND or large copper area for thermal dissipation but not used as sole GND electrode.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1703T-1802E/MB and XC6210B182MR-G, the AP7347D-18FDZW-7B uniquely combines automotive-ready 500mA drive, wettable flank inspection capability, auto-discharge, and best-in-class 75dB/60µV_rms noise-PSRR tradeoff - making it the only qualified option for ASIL-B adjacent subsystems requiring robust 1.8V regulation.

Availability

AP7347D-18FDZW-7B is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor nodes, medical wearables, and consumer audio subsystems requiring stable component supply, long-term lifecycle support, and AEC-Q100-aligned reliability.

Supply support for AP7347D-18FDZW-7B 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, with design centers across Asia, Europe, and the U.S., serving automotive, industrial, and consumer markets.

The AP7347D series belongs to Diodes' high-PSRR, low-noise LDO product line, engineered specifically for noise-critical automotive infotainment, ADAS, and body electronics where clean, stable, and reliable low-voltage regulation is mandatory.

FAQ

What is the maximum allowable input voltage for AP7347D-18FDZW-7B?

The absolute maximum input voltage is 6.0V, but the recommended operating range is 1.7V to 5.5V. Exceeding 5.5V risks permanent damage even briefly, and operation above 5.5V voids parametric guarantees including dropout, PSRR, and thermal performance. For 12V automotive systems, a pre-regulator stage is required.

Does AP7347D-18FDZW-7B require an external pull-up resistor on the EN pin?

No external pull-up is required. When unused, EN should be tied directly to VIN to maintain regulation. The internal EN input structure accepts direct connection to 1.8V or 3.3V logic without external biasing; however, floating EN is strictly prohibited as it may cause erratic enable/disable behavior and increased leakage current.

Can AP7347D-18FDZW-7B be used without the exposed pad connected?

No. The exposed pad (EP) must be soldered to a ≥40mm² GND copper area on the PCB. Leaving it unconnected violates thermal design requirements: junction-to-ambient thermal resistance rises from 54°C/W to >120°C/W, causing premature thermal shutdown at <200mA load and violating JEDEC Std. 51 derating guidelines.

Is AP7347D-18FDZW-7B qualified to AEC-Q100 standards?

The AP7347D-18FDZW-7B itself is not AEC-Q100 certified; however, it shares identical die, process, and electrical specifications with the AP7347DQ-18FDZW-7B, which is fully qualified to AEC-Q100 Grade 1 (–40°C to +125°C). Customers requiring automotive qualification must order the Q-suffix variant.