Diodes Incorporated AP7343D-12FS4-7

Overview

AP7343D-12FS4-7 from Diodes Incorporated is a 300mA, 1.2V fixed-output low-dropout linear regulator (LDO) with enable control, ±1% output voltage accuracy, 75dB PSRR at 1kHz, and 60µV_rms output noise (10Hz–100kHz). Fabricated on a CMOS process, it delivers high PSRR and low quiescent current (35µA typical) for RF supply rails in space-constrained portable devices.

For engineers reviewing the AP7343D-12FS4-7 datasheet, AP7343D-12FS4-7 pinout, AP7343D-12FS4-7 application, or AP7343D-12FS4-7 equivalent, key selection criteria include its 1.7V–5.25V input range, 0.26V typical dropout at 300mA (V_OUT = 2.1V), thermal shutdown at +150°C, and compatibility with 1µF ceramic input/output capacitors in ultra-small X2-DFN1010-4 (Type B) packaging.

Technical Context

The AP7343D-12FS4-7 integrates a precision voltage reference, error amplifier, current-limit circuit, and thermal shutdown protection. Its CMOS-based architecture enables low quiescent current and fast load transient response-critical for powering sensitive analog/RF blocks where supply noise and stability directly impact signal integrity.

This variant includes an active discharge function (denoted by "D" suffix), which pulls V_OUT to GND via a 30Ω internal N-channel MOSFET when EN is low, preventing floating outputs and enabling controlled power sequencing in multi-rail systems.

Key Specifications

Pinout & Package

AP7343D-12FS4-7 uses the X2-DFN1010-4 (Type B) package-a 1.0mm × 1.0mm, 0.4mm pitch, 4-terminal surface-mount package with an exposed thermal pad (EP). The EP must be connected to a large copper area tied to GND for optimal thermal dissipation (R_θJA = 237°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP7343D-12FS4-7, AP7361D-12YG-7 trades footprint and discharge capability for higher current, while MCP1700T-1202E/TT sacrifices control features and accuracy for minimal quiescent draw-making AP7343D-12FS4-7 the balanced choice for compact, sequenced, noise-sensitive 300mA loads.

Availability

AP7343D-12FS4-7 is available at Aetrix Electronics and suitable for RF power amplifier biasing, camera sensor core supply, Bluetooth LE SoC core rails, and wearable MCU subsystems requiring stable component supply, tight voltage tolerance, and ultra-small packaging.

Supply support for AP7343D-12FS4-7 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 AP7343 series targets portable and battery-powered electronics, delivering high PSRR, low noise, and miniature packaging to meet stringent size and efficiency demands in smartphones, wearables, and IoT edge devices.

FAQ

What is the purpose of the exposed pad (EP) on the X2-DFN1010-4 package?

The exposed pad (EP) serves exclusively as a thermal conduction path-not an electrical terminal. It must be soldered to a large GND-connected copper area using ≥4 thermal vias to achieve R_θJA = 237°C/W. Using it as a standalone GND electrode risks thermal runaway and violates JEDEC layout guidelines.

Does AP7343D-12FS4-7 require an external discharge resistor?

No. The "D" suffix indicates integrated active discharge via a 30Ω N-channel MOSFET between VOUT and GND when EN is low. This eliminates the need for external components and ensures VOUT decays to <0.1V within 100µs under 1µF load-critical for avoiding back-powering in multi-rail systems.

Can AP7343D-12FS4-7 operate with only a 0.47µF input capacitor?

Yes-the datasheet specifies a minimum 0.47µF ceramic capacitor on VIN. However, for loads with >100mA step changes or noisy input sources (e.g., buck converter outputs), a 1µF capacitor is recommended to maintain stability and reduce input ripple coupling into VOUT.

How does the 75dB PSRR at 1kHz translate to real-world noise suppression?

A 75dB PSRR means input ripple at 1kHz is attenuated by ~5,600×-so a 100mV_p-p ripple on VIN results in only ~18µV_p-p on VOUT. This level of suppression prevents audible buzz in audio codecs and maintains <0.1° RMS jitter in 1.2V PLL supply rails.