Diodes Incorporated AP7340D-15FS4-7

Overview

AP7340D-15FS4-7 from Diodes Incorporated is a 150mA, fixed 1.5V output low-dropout linear regulator with ±1% output voltage accuracy, 75dB PSRR at 1kHz, and 60µV_rms output noise (10Hz–100kHz). It features enable control, ultra-low 35µA quiescent current, and operates from 1.7V to 5.25V input. Designed for RF supply rails in portable wireless devices, it delivers stable low-noise bias under fast load transients.

For engineers reviewing the AP7340D-15FS4-7 datasheet, AP7340D-15FS4-7 pinout, AP7340D-15FS4-7 application, or AP7340D-15FS4-7 equivalent, key selection criteria include dropout voltage at 150mA (0.38V typ), EN logic thresholds (0.5V_IL/1.3V_IH), thermal performance in X2-DFN1010-4, and built-in auto-discharge functionality distinguishing it from non-D variants.

Technical Context

The AP7340D integrates a CMOS-based error amplifier, precision voltage reference, and current-limit circuitry to maintain regulation across line (1.7–5.25V) and load (0–150mA) variations. Its internal architecture includes an N-channel pass transistor with 30Ω on-resistance for auto-discharge during shutdown.

Unlike the standard AP7340, the "D" suffix denotes integrated output discharge via an internal NMOS switch (R_ON = 30Ω), enabling rapid VOUT decay when EN is pulled low-critical for sequencing-sensitive systems like multi-rail mobile SoCs.

Key Specifications

Pinout & Package

The AP7340D-15FS4-7 is housed in a 1.0mm × 1.0mm X2-DFN1010-4 package with exposed thermal pad. This ultra-compact leadless package supports high-density PCB layouts and requires thermal copper pour connected to GND for optimal power dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-1502E/TT and TPS7A0515PDBVR, the AP7340D-15FS4-7 uniquely combines 150mA capacity, EN control, and integrated auto-discharge in a 1.0mm² footprint - eliminating external components required by alternatives for safe power-down sequencing.

Availability

AP7340D-15FS4-7 is available at Aetrix Electronics and suitable for RF supply, mobile camera sensor bias, wireless adapter baseband power, and portable media player audio codec applications requiring stable component supply, full traceability, and long-term lifecycle support.

Supply support for AP7340D-15FS4-7 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-performance power management, signal integrity, and protection solutions for consumer, industrial, and communications markets.

The AP7340 series belongs to Diodes' precision low-noise LDO portfolio, engineered specifically for noise-sensitive analog and RF subsystems in battery-powered portable electronics where size, efficiency, and signal integrity are critical.

FAQ

What is the purpose of the thermal pad on the AP7340D-15FS4-7 package?

The exposed thermal pad on the X2-DFN1010-4 package serves as the primary heat dissipation path. Diodes Incorporated recommends connecting it to a large copper pour tied to GND on the PCB to reduce junction temperature rise during 150mA operation. Thermal resistance θ_JA drops significantly with proper pad layout - critical for maintaining reliability at +85°C ambient.

How does the auto-discharge feature work in the AP7340D variant?

When the EN pin is driven low, an internal 30Ω NMOS transistor connects VOUT to GND, actively discharging output capacitance. This ensures VOUT falls rapidly (<100µs for 1µF load), preventing unintended device wake-up or latch-up in multi-rail systems. The standard AP7340 lacks this switch and relies on load leakage for discharge.

Can the AP7340D-15FS4-7 operate with input voltage below 1.7V?

No. The absolute minimum input voltage is 1.7V per datasheet specifications. Below this threshold, regulation fails and output collapses. At 1.5V input, even with 1.5V nominal output, the device cannot sustain dropout margin - confirmed by the 0.38V typical dropout requirement at 150mA, demanding ≥1.88V input for stable 1.5V output.

Why is a 0.47µF ceramic capacitor specified for both input and output?

The 0.47µF value is optimized for stability and transient response across the AP7340D's operating range. Ceramic capacitors provide low ESR and ESL, essential for damping oscillations and supplying instantaneous current during load steps. Placement within 1mm of VIN/VOUT/GND pins minimizes parasitic inductance that could degrade PSRR or cause instability.