Diodes Incorporated AP7343D-10FS4-7B

Overview

AP7343D-10FS4-7B from Diodes Incorporated is a 300mA, 1.0V fixed-output low-dropout linear regulator (LDO) in X2-DFN1010-4 (Type B) package, featuring ±1% output voltage accuracy, 75dB PSRR at 1kHz, 60µV_rms output noise (10Hz–100kHz), 35µA quiescent current, and integrated enable control. It delivers stable power to RF supplies and portable media subsystems where low noise and high PSRR are critical.

For engineers reviewing the AP7343D-10FS4-7B datasheet, AP7343D-10FS4-7B pinout, AP7343D-10FS4-7B application, or AP7343D-10FS4-7B equivalent, key selection criteria include dropout voltage at 300mA (0.46V typ. for 1.0V output), thermal shutdown threshold (+150°C), EN input logic thresholds (0.5V low / 1.3V high), and compatibility with 1µF ceramic input/output capacitors.

Technical Context

The AP7343D-10FS4-7B employs a CMOS-based architecture with integrated voltage reference, error amplifier, current limit circuit, and thermal shutdown protection. Its enable-controlled operation supports system-level power sequencing, while the built-in discharge function (indicated by "D" suffix) actively pulls VOUT to GND during shutdown to prevent back-powering of downstream circuitry.

This LDO operates across a 1.7V–5.25V input range and maintains regulation down to a 0.46V typical dropout at 300mA load for 1.0V output. The X2-DFN1010-4 (Type B) package provides 237°C/W junction-to-ambient thermal resistance and includes an exposed pad optimized for thermal dissipation when connected to PCB ground plane.

Key Specifications

Pinout & Package

X2-DFN1010-4 (Type B) package: 1.0mm × 1.0mm, 0.4mm pitch, 4 active terminals + exposed thermal pad (EP). EP must be connected to PCB ground plane for optimal thermal performance (R_θJB = 85.7°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP7343D-10FS4-7B, AP7361D-10SAG-7 trades discharge capability for higher current and slightly lower noise, while MCP1826-1002E/DB offers wider temperature tolerance and better regulation accuracy but lacks active discharge and has higher output noise-making AP7343D-10FS4-7B optimal for compact, battery-powered RF/audio systems requiring fast shutdown discharge.

Availability

AP7343D-10FS4-7B is available at Aetrix Electronics and suitable for RF power amplifiers, mobile camera sensor cores, wearable biometric hubs, and Bluetooth LE audio codecs requiring stable component supply, automotive-grade traceability, and long-term lifecycle support.

Supply support for AP7343D-10FS4-7B 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 for power management, signal integrity, and connectivity applications.

The AP7343 series belongs to Diodes' high-PSRR, low-noise LDO product line, designed specifically for power-sensitive portable and wireless communication devices demanding precision regulation, minimal footprint, and robust enable/discharge control.

FAQ

What is the purpose of the "D" suffix in AP7343D-10FS4-7B?

The "D" denotes integrated output discharge functionality: when the EN pin is driven low, an internal 30Ω N-channel MOSFET actively discharges the VOUT pin to GND. This prevents back-powering of downstream circuits, eliminates residual voltage-induced glitches during power sequencing, and is essential for systems with multiple independent power domains.

Can AP7343D-10FS4-7B operate from a 1.8V input while delivering 1.0V at 300mA?

Yes. With a 1.8V input, the typical dropout voltage is 0.46V, leaving 1.34V headroom-well above the 0.46V required to sustain 300mA at 1.0V output. The device remains in regulation across the full 1.7V–5.25V input range, and its CMOS architecture ensures stable operation even near the minimum VIN specification.

How does the X2-DFN1010-4 (Type B) package affect thermal performance compared to SOT25?

The X2-DFN1010-4 (Type B) has higher junction-to-ambient thermal resistance (237°C/W vs. 179°C/W for SOT25), but its exposed pad enables superior board-level thermal conduction when soldered to a large GND copper area. With proper layout, its junction-to-board resistance (85.7°C/W) supports continuous 300mA operation at +85°C ambient-matching SOT25's real-world thermal capability in dense PCBs.

Is an external resistor network required to set the 1.0V output?

No. AP7343D-10FS4-7B uses an internally trimmed resistor network to fix the output at 1.0V ±1%. No external components are needed for voltage setting-only 1µF ceramic input and output capacitors are required for stability and transient response, simplifying design and reducing BOM count.