Diodes Incorporated AP7315D-11FS4-7B

Overview

AP7315D-11FS4-7B from Diodes Incorporated is a 150mA low-dropout linear regulator with fixed 1.1V output, ±1% accuracy, 75dB PSRR at 1kHz, 60µVrms output noise (10Hz–100kHz), and 35µA quiescent current - designed for RF supply rails in compact portable electronics.

For engineers reviewing the AP7315D-11FS4-7B datasheet, AP7315D-11FS4-7B pinout, AP7315D-11FS4-7B application, or AP7315D-11FS4-7B equivalent, this device delivers high PSRR and ultra-low noise in a 1.0mm × 1.0mm X2-DFN1010-4 package with integrated enable control and auto-discharge functionality.

Technical Context

The AP7315D-11FS4-7B uses a CMOS-based LDO architecture with internal voltage reference, error amplifier, current limit circuit, and NMOS pass transistor. Its auto-discharge feature actively pulls VOUT to GND when EN is low, eliminating residual voltage on downstream loads.

It operates across 1.7V–5.25V input range, supports 150mA continuous output, and maintains regulation down to 210mV dropout (at 2.8V–3.3V VOUT); for its 1.1V variant, dropout is 500mV typical at 150mA. Thermal shutdown and short-circuit protection are embedded.

Key Specifications

Pinout & Package

AP7315D-11FS4-7B is housed in a 1.0mm × 1.0mm, 0.4mm pitch X2-DFN1010-4 package with wettable flank leads and an exposed thermal pad (not electrically connected). PCB layout requires thermal copper area under the pad, connected to GND for optimal junction temperature control.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP7315-11FS4-7B, the D-suffix variant adds essential auto-discharge for audio and RF systems requiring clean power-down; versus XC6210B112MR-G, it offers tighter accuracy, lower noise, and 40% smaller footprint - critical for space-constrained portable designs.

Availability

AP7315D-11FS4-7B is available at Aetrix Electronics and suitable for RF power amplifier bias, low-power microcontroller core supply, camera module analog front-end, and wireless Bluetooth audio codec supply requiring stable component supply across high-mix, low-volume production runs.

Supply support for AP7315D-11FS4-7B 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, with design, manufacturing, and distribution capabilities spanning Asia, Europe, and the Americas.

The AP7315 series belongs to Diodes' high-performance LDO portfolio, engineered specifically for noise-sensitive portable electronics - emphasizing PSRR, output accuracy, and miniaturized packaging for space-constrained RF and battery-powered applications.

FAQ

What is the purpose of the thermal pad on the AP7315D-11FS4-7B package?

The thermal pad is a non-electrical copper surface on the underside of the X2-DFN1010-4 package, designed solely for heat dissipation. It must be soldered to a large PCB copper area connected to GND to maintain junction temperature below 125°C at 150mA load. It is not a functional ground terminal and must not be used as the sole GND connection point.

Does the AP7315D-11FS4-7B 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 as close as possible to their respective pins. Larger capacitance (e.g., 2.2µF) improves transient response for pulsed loads, but ESR must remain below 100mΩ to ensure stability per the datasheet's ESR vs. IOUT graph.

How does the auto-discharge function operate, and when is it active?

The auto-discharge NMOS turns on only when EN is driven low (≤0.5V), creating a 30Ω path from VOUT to GND. It remains inactive during normal operation (EN ≥1.3V) and does not affect regulation or efficiency. Discharge time depends on C_OUT; with 0.47µF, VOUT falls from 1.1V to 0.1V in <100µs - critical for eliminating pop noise in audio paths and preventing unintended wake-up in RF receivers.

Can the AP7315D-11FS4-7B be used with input voltages below 1.7V?

No - the absolute minimum input voltage is 1.7V per the Absolute Maximum Ratings table. Operation below this threshold risks failure to regulate or unpredictable enable behavior. For sub-1.7V applications (e.g., coin-cell powered sensors), consider Diodes' AP2204K-11 or alternative ultra-low-VIN LDOs with verified 0.9V start-up capability.