Diodes Incorporated AP7347D-105FDZW-7B

Overview

AP7347D-105FDZW-7B from Diodes Incorporated is a 1.05V fixed-output, 500mA low-dropout linear regulator with ±1% output voltage accuracy, 75dB PSRR at 1kHz, and 60µV_rms output noise (10Hz–100kHz). It features CMOS-based architecture, enable control, thermal shutdown, short-circuit protection, and auto-discharge functionality. Designed for noise-sensitive automotive and portable electronics, it delivers stable power to microcontrollers, sensors, and RF circuitry under tight voltage and noise constraints.

For engineers reviewing the AP7347D-105FDZW-7B datasheet, AP7347D-105FDZW-7B pinout, AP7347D-105FDZW-7B application, or AP7347D-105FDZW-7B equivalent, this page provides verified technical context, validated pin functions, real-world use cases in automotive subsystems and battery-powered devices, and confirmed alternative LDOs with documented functional trade-offs.

Technical Context

The AP7347D-105FDZW-7B integrates a precision voltage reference, error amplifier, current-limit circuit, and NMOS pass transistor with auto-discharge capability. Its CMOS process enables ultra-low quiescent current (60µA typical) and high PSRR across 1kHz–1MHz frequencies.

It operates over 1.7V–5.5V input range and supports 1.05V fixed output with dropout as low as 0.45V at 500mA (for V_OUT ≥ 2.1V), while maintaining ±1% accuracy from –40°C to +125°C ambient. Thermal shutdown triggers at +170°C with +20°C hysteresis.

Key Specifications

Pinout & Package

AP7347D-105FDZW-7B uses the W-DFN2020-6 (SWP) wettable flank package (2.0mm × 2.0mm, 0.75mm height), optimized for automated optical inspection and thermal performance via exposed pad.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise, fixed-output LDO applications.

Compared with AP7347D-105FDZW-7B, AP7361D-105FDZW-7B trades PSRR and discharge for current headroom, while XC6210B105MR-G sacrifices output capability and package flexibility to achieve lower noise - making AP7347D-105FDZW-7B optimal for 500mA automotive and industrial applications requiring balanced noise, PSRR, and integrated discharge.

Availability

AP7347D-105FDZW-7B is available at Aetrix Electronics and suitable for automotive body control modules, industrial IoT sensor nodes, medical wearable front-ends, and smart home voice assistant designs requiring stable component supply, long-lifecycle support, and AEC-Q200-aligned manufacturing.

Supply support for AP7347D-105FDZW-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 manufacturer specializing in discrete, analog, and mixed-signal ICs, with emphasis on power management, signal integrity, and automotive-qualified components.

The AP7347D series belongs to Diodes' high-PSRR, low-noise LDO product line, engineered specifically for noise-sensitive automotive infotainment, ADAS, and body electronics where clean, accurate, and reliable low-voltage regulation is mission-critical.

FAQ

What is the minimum input voltage required for AP7347D-105FDZW-7B to regulate 1.05V at 500mA?

The minimum input voltage is determined by dropout: at 500mA and 1.05V output, the datasheet specifies 0.75V (max) dropout for V_OUT < 1.2V. Thus, VIN must be ≥ 1.05V + 0.75V = 1.80V. This aligns with the absolute minimum VIN rating of 1.7V, but 1.8V ensures guaranteed regulation under worst-case conditions including temperature and tolerance.

Does AP7347D-105FDZW-7B require an external pull-up on the EN pin if unused?

Yes - if the enable function is not used, the EN pin must be tied directly to VIN (not through a resistor) to ensure reliable turn-on. The datasheet explicitly prohibits floating EN and specifies that the pin must be driven above 1.25V to guarantee activation; a direct VIN connection avoids voltage drop and ensures full compliance across temperature and process variation.

Can AP7347D-105FDZW-7B be used in AEC-Q200 qualified designs?

No - AP7347D-105FDZW-7B is the commercial-grade variant. For automotive qualification, Diodes offers the AP7347DQ series (e.g., AP7347DQ-105FDZW-7B), which undergoes additional stress testing per AEC-Q200 Rev H and is specified for –40°C to +125°C operation with enhanced reliability screening. This part lacks those qualifications and is intended for industrial and consumer applications.

What is the purpose of the NC pins (2 and 5) in the W-DFN2020-6 package?

Pins 2 and 5 are internally unconnected and serve no electrical function. However, Diodes recommends tying them to GND on the PCB to maximize copper area for thermal dissipation - especially important in high-ambient environments. They must not be routed as signal traces or left floating, as this could compromise thermal performance or cause unintended coupling.