Diodes Incorporated AP7343D-20FS4-7B

Overview

AP7343D-20FS4-7B from Diodes Incorporated is a 300mA, 2.0V fixed-output low-dropout regulator with ±1% output accuracy, 75dB PSRR at 1kHz, 60µVrms output noise (10Hz–100kHz), and 35µA quiescent current. Packaged in X2-DFN1010-4 (Type B), it delivers high PSRR and low-noise regulation for RF supply rails in portable wireless devices.

For engineers reviewing the AP7343D-20FS4-7B datasheet, AP7343D-20FS4-7B pinout, AP7343D-20FS4-7B application, or AP7343D-20FS4-7B equivalent, key selection criteria include dropout voltage (≤390mV @ 300mA, VOUT=2.0V), enable logic thresholds (EN low ≤0.5V, high ≥1.3V), thermal shutdown (150°C), and discharge functionality enabled by the "D" suffix.

Technical Context

The AP7343D integrates a CMOS-based LDO architecture with internal voltage reference, error amplifier, current limit, and thermal shutdown circuitry. Its enable-controlled operation supports system-level power sequencing, while the built-in auto-discharge path (enabled by "D") actively pulls VOUT to GND during shutdown to prevent floating bias in downstream circuitry.

This device operates across 1.7V–5.25V input range and maintains stable 2.0V output under load transients up to 300mA. It achieves 75dB ripple rejection at 1kHz and sustains <±30ppm/°C output voltage drift over –40°C to +85°C ambient, making it suitable for precision analog and RF supply domains.

Key Specifications

Pinout & Package

Packaged in X2-DFN1010-4 (Type B) - a 1.0mm × 1.0mm, 0.4mm pitch, 4-pin DFN with exposed thermal pad (EP). The EP must be connected to GND via large copper area for optimal thermal dissipation (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 MCP1700T-2002E/MB and XC6210B202MR-G, the AP7343D-20FS4-7B uniquely combines 300mA drive, enable-controlled auto-discharge, and 75dB PSRR-making it the only option among the three qualified for RF PA bias and fast-wake sensor hubs requiring controlled VOUT collapse.

Availability

AP7343D-20FS4-7B is available at Aetrix Electronics and suitable for RF power amplifier bias, camera ISP supply, Bluetooth LE audio codec regulation, and wearable sensor hub core rail applications requiring stable component supply, automotive-grade traceability, and long-term lifecycle support.

Supply support for AP7343D-20FS4-7B 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 noise-sensitive portable electronics including smartphones, tablets, and wireless communication modules.

FAQ

What is the purpose of the "D" suffix in AP7343D-20FS4-7B?

The "D" denotes built-in auto-discharge functionality: when the EN pin is pulled low, an internal 30Ω NMOS switch connects VOUT to GND, actively discharging output capacitance. This prevents residual voltage from interfering with downstream circuit reset timing or causing latch-up in powered-down sections.

Can AP7343D-20FS4-7B operate from a 2.4V lithium coin cell?

Yes-it supports input voltages as low as 1.7V and has a maximum dropout of 390mV at 300mA. With a 2.0V output, it remains functional down to ~2.39V input, covering the full discharge curve of common CR2032 cells (2.0V–3.0V), provided load current stays ≤300mA.

Is the exposed pad (EP) electrically connected to GND?

No-the EP is a thermal pad only, not an electrical terminal. It must be soldered to a PCB copper area connected to GND for thermal conduction, but it must not serve as the sole GND connection. Pin 2 (GND) remains the mandatory signal ground reference.

How does the AP7343D-20FS4-7B handle short-circuit conditions?

It features fold-back current limiting that clamps output current to ~55mA when VOUT is shorted to GND. Combined with thermal shutdown at +150°C (with +20°C hysteresis), this protects the device from damage during sustained fault conditions without requiring external current-sense circuitry.