Diodes Incorporated AP7340D-22FS4-7

Overview

AP7340D-22FS4-7 from Diodes Incorporated is a 2.2V fixed-output, 150mA low-dropout linear regulator with ±1% output voltage accuracy, 75dB PSRR at 1kHz, 60µV_rms output noise (10Hz–100kHz), and 35µA quiescent current. It features enable control, thermal shutdown, short-circuit protection, and an integrated discharge FET - making it suitable for powering RF supply rails in portable wireless communication devices.

For engineers reviewing the AP7340D-22FS4-7 datasheet, AP7340D-22FS4-7 pinout, AP7340D-22FS4-7 application, or AP7340D-22FS4-7 equivalent, key selection criteria include dropout voltage at 150mA (0.21–0.27V), EN logic thresholds (0.5V_IL/1.3V_IH), thermal pad handling, and compatibility with 0.47µF ceramic input/output capacitors in space-constrained layouts.

Technical Context

The AP7340D-22FS4-7 uses a CMOS-based LDO architecture with internal voltage reference, error amplifier, and current-limit circuitry. Its built-in discharge FET actively pulls VOUT to GND when disabled, eliminating residual voltage on downstream circuits - critical for power sequencing in multi-rail systems.

It operates across 1.7V–5.25V input range and maintains regulation down to 2.2V output with ≤0.27V dropout at full 150mA load. The device achieves 75dB ripple rejection at 1kHz and delivers ultra-low 60µV_rms noise, enabling clean biasing of sensitive RF and analog circuitry.

Key Specifications

Pinout & Package

The AP7340D-22FS4-7 is housed in a 1.0mm × 1.0mm X2-DFN1010-4 package with exposed thermal pad. PCB layout requires direct connection of the thermal pad to GND plane for optimal thermal dissipation and EMI suppression.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP7340D-22FS4-7, AP7361D-22YG-13 offers +150mA current but sacrifices discharge functionality and adds 30µA quiescent current; MCP1826-2202E/DB trades 10dB PSRR and board area efficiency for broader vendor support and mature qualification history.

Availability

AP7340D-22FS4-7 is available at Aetrix Electronics and suitable for RF power amplifier bias, camera ISP supply, and portable media player audio codec applications requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for AP7340D-22FS4-7 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 manufacturer of discrete semiconductors and analog ICs, specializing in high-efficiency power management, signal integrity, and protection solutions for consumer, industrial, and communications markets.

The AP7340 series targets space-constrained, battery-powered portable electronics - designed specifically to deliver ultra-low noise, high PSRR, and fast transient response in sub-1mm² DFN packages for RF and imaging subsystems.

FAQ

What is the function of the thermal pad on the AP7340D-22FS4-7 package?

The exposed thermal pad on the X2-DFN1010-4 package serves as the primary heat dissipation path. It must be soldered to a large copper area connected to GND for optimal thermal performance and EMI reduction. Leaving it unconnected degrades thermal resistance by >50% and risks thermal shutdown under 150mA load.

Does AP7340D-22FS4-7 require external capacitors, and what values are recommended?

Yes - a minimum 0.47µF ceramic capacitor is required between VIN and GND, and another 0.47µF ceramic capacitor between VOUT and GND. Both must be placed within 1mm of their respective pins. Larger bulk capacitance may be added in parallel for high-dV/dt loads, but the 0.47µF ceramics are mandatory for stability and transient response.

How does the discharge FET operate during shutdown?

When EN is pulled low (<0.5V), the internal N-channel FET turns on and actively discharges the VOUT node to GND through a typical 30Ω on-resistance. This ensures rapid VOUT decay (<100µs for 1µF load), preventing unintended operation of downstream logic or analog circuits during power-down sequences.

Can AP7340D-22FS4-7 be used with input voltages below 2.2V?

No - the minimum input voltage is 1.7V, but dropout voltage increases sharply below VOUT + 0.27V. At 2.2V output, operation below ~2.47V input results in loss of regulation. For 2.2V output, maintain VIN ≥2.5V to ensure full 150mA capability and ±1% accuracy across temperature.