Diodes Incorporated AP7340-36FS4-7

Overview

AP7340-36FS4-7 from Diodes Incorporated is a 3.6V fixed-output, 150mA low-dropout linear regulator with ±1% output voltage accuracy, 75dB PSRR at 1kHz, and 60µV_RMS output noise (10Hz–100kHz). Built on a CMOS process, it features enable control, low 35µA quiescent current, and operates from 1.7V to 5.25V input. It powers RF supply rails in compact portable devices where stable, low-noise biasing is critical.

For engineers reviewing the AP7340-36FS4-7 datasheet, AP7340-36FS4-7 pinout, AP7340-36FS4-7 application, or AP7340-36FS4-7 equivalent, key selection criteria include dropout voltage at 150mA (0.21–0.27V for 3.6V output), EN logic thresholds (0.5V_IL/1.3V_IH), thermal performance in X2-DFN1010-4, and compatibility with 0.47µF ceramic input/output capacitors.

Technical Context

The AP7340-36FS4-7 integrates a precision voltage reference, error amplifier, and NMOS pass transistor with low R_DS(ON) to achieve high PSRR and tight load/line regulation (0.1%/V line, 1.0%/A load). Its CMOS architecture enables ultra-low quiescent current (35µA typ.) while maintaining fast transient response under dynamic loads up to 150mA.

Enable functionality is implemented via a dedicated EN pin with defined logic thresholds (V_IL ≤ 0.5V, V_IH ≥ 1.3V) and sub-1µA standby leakage. The device lacks auto-discharge (non-D variant), requiring external discharge paths when rapid V_OUT decay is needed after shutdown.

Key Specifications

Pinout & Package

The AP7340-36FS4-7 is housed in a 1.0mm × 1.0mm X2-DFN1010-4 package with exposed thermal pad (not electrically connected to GND by default); recommended PCB layout uses large copper area tied to GND for thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-3602E/TO and XC6219B362MR-G, the AP7340-36FS4-7 delivers superior RF-grade noise suppression (60µV_RMS, 75dB PSRR) and tighter voltage accuracy (±1%), making it uniquely suited for sensitive analog and RF supply domains where signal integrity is non-negotiable.

Availability

AP7340-36FS4-7 is available at Aetrix Electronics and suitable for RF power amplifier bias, camera ISP analog supplies, wireless adapter core logic, and portable media player audio codecs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AP7340-36FS4-7 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-performance, energy-efficient components for consumer, computing, industrial, and communications markets.

The AP7340 belongs to Diodes' high-PSRR, low-noise LDO family designed specifically for noise-sensitive analog and RF subsystems in portable electronics where battery life, board space, and signal purity are critical constraints.

FAQ

What is the maximum allowable input voltage for AP7340-36FS4-7?

The absolute maximum input voltage is 6.0V. Operation above 5.25V violates recommended conditions and risks permanent damage. For reliable long-term use, VIN must remain between 1.7V and 5.25V, with sufficient margin to accommodate ripple and transients-especially when sourced from a DC-DC converter with ±5% tolerance.

Does AP7340-36FS4-7 include an output discharge function?

No. The AP7340-36FS4-7 is the non-discharge variant (standard AP7340, not AP7340D). When disabled via EN, the output remains floating and does not actively pull VOUT to GND. If rapid output discharge is required, an external resistor or MOSFET-based bleed circuit must be added between VOUT and GND.

Can AP7340-36FS4-7 operate with ceramic capacitors smaller than 0.47µF?

No. The datasheet specifies 0.47µF ceramic capacitors for both CIN and COUT to ensure stability and meet transient response requirements. Using smaller values may cause oscillation or excessive overshoot/undershoot during load steps, especially at 150mA. The device is optimized for this value-not minimum-capacitance.

How is thermal performance affected by the X2-DFN1010-4 thermal pad connection?

Thermal resistance θ_JA drops significantly when the exposed thermal pad is soldered to a large GND-connected copper pour (e.g., ≥25mm²). Leaving the pad unconnected or floating increases junction-to-ambient resistance by ~30°C/W, risking thermal shutdown at 150mA in still-air conditions. PCB layout must follow Diodes' AP02001 pad recommendations.