Diodes Incorporated AP7343D-16FS4-7B

Overview

AP7343D-16FS4-7B from Diodes Incorporated is a 300mA, 1.6V 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), and 35µA quiescent current - optimized for RF supply rails in compact portable electronics.

For engineers reviewing the AP7343D-16FS4-7B datasheet, AP7343D-16FS4-7B pinout, AP7343D-16FS4-7B application, or AP7343D-16FS4-7B equivalent, key selection criteria include dropout voltage at 300mA (0.35V typ. for 1.6V V_OUT), enable-controlled shutdown with <0.5V logic-low threshold, thermal shutdown at +150°C, and compatibility with 1µF ceramic input/output capacitors.

Technical Context

The AP7343D-16FS4-7B implements a CMOS-based LDO architecture with integrated voltage reference, error amplifier, current-limit circuit, and active discharge path (enabled by "D" suffix). Its EN pin controls regulator state with defined logic thresholds (V_IL ≤ 0.5V, V_IH ≥ 1.3V), and it includes thermal shutdown (+150°C) with 20°C hysteresis.

Designed for high-PSRR, low-noise operation, it achieves 75dB ripple rejection at 1kHz and maintains stability with minimal 1µF ceramic output capacitance. The device supports wide input range (1.7V–5.25V), delivers guaranteed 300mA output, and exhibits ±30ppm/°C output voltage temperature coefficient over –40°C to +85°C.

Key Specifications

Pinout & Package

X2-DFN1010-4 (Type B) package: 1.0mm × 1.0mm, 0.4mm pitch, exposed thermal pad (EP) - requires PCB copper area connected to GND for optimal thermal performance (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 MCP1804T-1602I/OT and XC6210B162MR-G, the AP7343D-16FS4-7B uniquely combines 300mA drive, 35µA I_Q, integrated discharge, and industry-leading 75dB PSRR in a 1.0mm² DFN - making it optimal for space-constrained, noise-critical RF and imaging applications requiring fast enable/disable control.

Availability

AP7343D-16FS4-7B is available at Aetrix Electronics and suitable for RF power amplifier biasing, camera ISP supplies, wireless communication module cores, and portable media player audio codecs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AP7343D-16FS4-7B 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 manufacturer of discrete semiconductors and analog ICs, specializing in high-performance power management, signal integrity, and connectivity solutions for consumer, industrial, and automotive markets.

The AP7343 series belongs to Diodes' high-PSRR, low-noise LDO product line, engineered specifically for noise-sensitive applications in portable communications equipment where small size, low power, and robust transient response are mandatory.

FAQ

What is the purpose of the "D" suffix in AP7343D-16FS4-7B?

The "D" denotes integrated active discharge functionality: when the EN pin is pulled low, an internal NMOS transistor pulls VOUT to GND, rapidly discharging output capacitance. This eliminates need for external bleed resistors and prevents unintended back-powering of upstream circuits during shutdown - confirmed in datasheet Section 1.1 and Pin Descriptions table.

Can AP7343D-16FS4-7B operate with only 1µF input and output capacitors?

Yes - the device is explicitly characterized and guaranteed stable with 1µF ceramic capacitors on both VIN and VOUT (per Application Information Section 12 and Typical Characteristics). Layout best practices require placing CIN within 2mm of PIN4 (VIN) and COUT adjacent to PIN1 (VOUT) and PIN2 (GND) to minimize parasitic inductance.

What is the maximum allowable input voltage for continuous operation?

The absolute maximum VIN is 6.0V (per Absolute Maximum Ratings Table), but recommended continuous operating range is 1.7V to 5.25V (per Recommended Operating Conditions). Exceeding 5.25V risks permanent damage even briefly; operation above 5.25V violates specification and voids reliability guarantees.

How does thermal performance differ between X2-DFN1010-4 (Type B) and SOT25 packages?

X2-DFN1010-4 (Type B) has R_θJA = 237°C/W vs. SOT25's 179°C/W (per Package Thermal Information Table), meaning the DFN runs hotter at same power dissipation. However, its exposed pad enables superior board-level thermal conduction (R_θJB = 85.7°C/W vs. 79.2°C/W), making it preferable for dense layouts where airflow is limited and PCB copper area can be allocated for heat spreading.