Diodes Incorporated AP7343Q-18W5-7

Overview

AP7343Q-18W5-7 from Diodes Incorporated is an automotive-grade 300mA low-dropout regulator with fixed 1.8V output, ±1% accuracy, 75dB PSRR at 1kHz, 60µV_rms output noise (10Hz–100kHz), and 35µA quiescent current. It features enable control, thermal shutdown, and short-circuit protection, and is used in noise-sensitive automotive power domains including ADAS camera rails and infotainment SoC core supplies.

For engineers reviewing the AP7343Q-18W5-7 datasheet, AP7343Q-18W5-7 pinout, AP7343Q-18W5-7 application, or AP7343Q-18W5-7 equivalent, key selection criteria include AEC-Q100 Grade 1 qualification, SOT25 package thermal performance (θ_JA = 179°C/W), dropout voltage of 0.35V at 300mA (for V_OUT = 1.8V), and EN input logic thresholds (V_IL ≤ 0.5V, V_IH ≥ 1.3V).

Technical Context

The AP7343Q-18W5-7 implements a CMOS-based LDO architecture with integrated voltage reference, error amplifier, current limit circuit, and thermal shutdown. Its design targets automotive power integrity requirements: guaranteed operation from –40°C to +125°C ambient, input voltage range of 1.7V to 5.25V, and stable regulation under fast load transients (e.g., 1mA ↔ 300mA step with <100mV undershoot/overshoot using 1µF C_OUT).

It lacks internal discharge functionality (non-discharge variant), requires external 1µF input and output ceramic capacitors, and relies on the EN pin for precise sequencing control-pulling EN low disables the regulator with standby current ≤1.0µA, while EN high enables regulation with typical turn-on time <100µs at 300mA load.

Key Specifications

Pinout & Package

AP7343Q-18W5-7 is packaged in SOT25 (5-pin, 2.9mm × 2.8mm × 1.3mm), optimized for space-constrained automotive PCBs with exposed pad thermal enhancement. The package supports wettable flank inspection and meets IATF 16949 manufacturing controls.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP7343Q-18W5-7, AP7361Q-18W5-7 offers higher current headroom at the cost of slightly higher quiescent current and dropout, while TLD1114-18ES trades noise and accuracy for broader vendor availability-making AP7343Q-18W5-7 optimal for noise- and accuracy-critical automotive LDO roles.

Availability

AP7343Q-18W5-7 is available at Aetrix Electronics and suitable for automotive infotainment systems, ADAS camera modules, and vehicle telematics platforms requiring stable component supply with full AEC-Q100 compliance and PPAP documentation support.

Supply support for AP7343Q-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 manufacturer specializing in discrete, analog, and mixed-signal solutions for automotive, industrial, and consumer markets, with ISO/TS 16949 and IATF 16949 certified facilities.

The AP7343Q belongs to Diodes' automotive-qualified LDO portfolio, engineered specifically for noise-sensitive power domains in ADAS, infotainment, and body electronics where high PSRR, low noise, and AEC-Q100 reliability are mandatory.

FAQ

What is the maximum allowable input voltage for AP7343Q-18W5-7?

The absolute maximum input voltage is 6.0V, but the recommended operating range is 1.7V to 5.25V. Exceeding 5.25V may trigger overvoltage protection or degrade long-term reliability, especially at elevated temperatures. Operation above 5.25V is not characterized and violates AEC-Q100 stress limits.

Does AP7343Q-18W5-7 include an internal discharge path for VOUT?

No, AP7343Q-18W5-7 is the non-discharge variant (as indicated by "Q" suffix, not "DQ"). When disabled via EN pin, VOUT remains floating and does not actively discharge through an internal FET. An external bleed resistor or dedicated discharge circuit is required if rapid VOUT decay is needed for system sequencing.

Can AP7343Q-18W5-7 operate with ceramic output capacitors smaller than 1µF?

The datasheet specifies stability with ≥1µF ceramic output capacitance. Using smaller values (e.g., 0.47µF) may cause instability or excessive ringing under load transients, particularly at high output currents. Diodes validates performance only with 1µF or larger low-ESR ceramics meeting the ESR vs. I_OUT stability region shown in Figure 17.

How is thermal performance affected when mounting AP7343Q-18W5-7 on a 2-layer PCB?

On a standard 2-layer board without internal ground/power planes, θ_JA degrades significantly-measured data assumes a JEDEC High-K 4-layer test board. Real-world θ_JA may exceed 250°C/W, limiting continuous 300mA operation above +85°C ambient. Use generous copper pour on both layers connected to GND and the NC pin to mitigate this.