Diodes Incorporated AP7340D-33FS4-7

Overview

AP7340D-33FS4-7 from Diodes Incorporated is a 3.3V fixed-output, 150mA 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 bias under fast load transients.

For engineers reviewing the AP7340D-33FS4-7 datasheet, AP7340D-33FS4-7 pinout, AP7340D-33FS4-7 application, or AP7340D-33FS4-7 equivalent, key selection criteria include dropout voltage at 150mA (0.21–0.27V), EN logic thresholds (0.5V low / 1.3V high), thermal performance in X2-DFN1010-4, and discharge capability for rapid VOUT decay during shutdown.

Technical Context

The AP7340D variant integrates an active discharge MOSFET between VOUT and GND, enabling controlled output voltage decay when disabled-critical for sequencing-sensitive systems. Its CMOS-based error amplifier and reference achieve ±1% initial accuracy and ±30ppm/°C temperature coefficient.

Designed for high-PSRR noise suppression in RF signal chains, it maintains 75dB rejection at 1kHz while delivering 150mA with only 35µA quiescent current in active mode and 0.01µA in shutdown. The X2-DFN1010-4 package's thermal pad supports efficient heat dissipation in space-constrained layouts.

Key Specifications

Pinout & Package

X2-DFN1010-4 (1.0mm × 1.0mm, 0.4mm height) with exposed thermal pad - optimized for minimal PCB footprint and high-density portable designs; thermal pad must be connected to GND plane for optimal junction-to-board thermal resistance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-3302E/TT and XC6210B332MR-G, AP7340D-33FS4-7 uniquely balances ultra-small X2-DFN1010-4 size, integrated discharge, and best-in-class 75dB PSRR - making it optimal for space-constrained RF and imaging subsystems requiring precise sequencing and noise immunity.

Availability

AP7340D-33FS4-7 is available at Aetrix Electronics and suitable for smartphone baseband power, RF transceiver bias, camera sensor analog rails, and wireless audio codec supply requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for AP7340D-33FS4-7 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 consumer, industrial, and communications markets.

The AP7340 series belongs to Diodes' high-performance LDO portfolio, engineered specifically for noise-sensitive portable electronics requiring ultra-low I_Q, fast transient response, and compact packaging.

FAQ

What is the purpose of the thermal pad on the AP7340D-33FS4-7 package?

The exposed thermal pad on the X2-DFN1010-4 package is a non-electrical mechanical feature designed solely for thermal conduction. It must be soldered to a GND-connected copper pour on the PCB to reduce junction-to-board thermal resistance by up to 30°C/W. Leaving it unconnected or floating degrades thermal performance and risks thermal shutdown under sustained 150mA load.

Does AP7340D-33FS4-7 require external capacitors, and what values are recommended?

Yes - AP7340D-33FS4-7 requires both input (CIN) and output (COUT) ceramic capacitors. A minimum 0.47µF X5R/X7R capacitor is specified for both pins, placed within 2mm of the device. For high-dynamic-load applications like RF PA biasing, adding a 4.7µF bulk capacitor in parallel with COUT improves transient response and reduces output voltage undershoot during 100mA step changes.

How does the "D" suffix in AP7340D differ from standard AP7340?

The "D" suffix denotes integrated active discharge functionality: when EN is pulled low, an internal 30Ω NMOS switch connects VOUT to GND, discharging the output capacitor rapidly (<100µs to <0.1V). Standard AP7340 lacks this feature, leaving VOUT floating or slowly decaying via load leakage - critical for power sequencing in multi-rail SoC systems where reverse current or voltage hold-up must be avoided.

Can AP7340D-33FS4-7 operate with a 1.8V input supply?

No - AP7340D-33FS4-7 requires a minimum input voltage of 1.7V, but its dropout voltage at 150mA is 0.21–0.27V for 3.3V output. At 1.8V input, maximum sustainable output current drops to <10mA before regulation fails. For reliable 150mA operation at 3.3V, VIN must be ≥3.51V. Use only within validated 1.7–5.25V input range per datasheet Section 6.