Diodes Incorporated AP7353D-36FS4-7

Overview

AP7353D-36FS4-7 from Diodes Incorporated is a 250mA low-dropout linear regulator with fixed 3.6V output, high PSRR (90dB at 1kHz), ultra-low output noise (10µV_rms), and 18µA typical quiescent current. Packaged in the X2-DFN1010-4 (Type B) footprint, it delivers stable power to noise-sensitive RF and analog circuits in space-constrained portable electronics.

For engineers reviewing the AP7353D-36FS4-7 datasheet, AP7353D-36FS4-7 pinout, AP7353D-36FS4-7 application, or AP7353D-36FS4-7 equivalent, key selection criteria include dropout voltage at 250mA (max 119mV @ V_OUT=3.6V), EN pin logic thresholds (V_IL ≤ 0.4V, V_IH ≥ 1.2V), thermal resistance (θ_JA = 237°C/W), and discharge functionality for fast output discharge during shutdown.

Technical Context

The AP7353D integrates a CMOS-based error amplifier, precision voltage reference, current-limit circuit, and thermal shutdown protection. Its built-in auto-discharge path (35Ω N-channel MOSFET) actively pulls the output to ground when disabled, eliminating external discharge components.

It operates across 2.0V–5.5V input range with ±1% output voltage accuracy over load (1–250mA), temperature (−40°C to +85°C), and line variations. Fast load transient response (<20µs settling time) and 70dB PSRR at 10kHz support dynamic RF supply rails requiring minimal ripple coupling.

Key Specifications

Pinout & Package

Packaged in the X2-DFN1010-4 (Type B) 1.0mm × 1.0mm, 0.4mm pitch, thermally enhanced leadless package with exposed pad (EP) for improved heat dissipation. Requires PCB copper area connected to GND under EP for optimal thermal performance (θ_JA = 237°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1703T-3602E/MB and XC6210B362MR-G, AP7353D-36FS4-7 uniquely combines 250mA output, 10µV_rms noise, 35Ω discharge FET, and 1.0mm² DFN1010 packaging - making it optimal for miniaturized RF and audio systems demanding both performance and board-area efficiency.

Availability

AP7353D-36FS4-7 is available at Aetrix Electronics and suitable for smartphone RF supplies, wearable sensor nodes, and digital camera image sensor biasing requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for AP7353D-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 semiconductor company specializing in discrete, analog, and mixed-signal devices, with design, manufacturing, and distribution operations across Asia, Europe, and the Americas.

The AP7353 series targets portable and battery-powered applications requiring high PSRR, low noise, and ultra-low IQ - specifically engineered for RF, imaging, and wearables where power integrity directly impacts signal fidelity and runtime.

FAQ

What is the function of the exposed pad (EP) on AP7353D-36FS4-7?

The exposed pad is a thermal enhancement feature, not an electrical terminal. It must be soldered to a PCB copper area connected to GND to reduce thermal resistance (θ_JA = 237°C/W). It should never serve as the sole GND connection - dedicated GND pin (Pin 2) remains the primary current return path.

Does AP7353D-36FS4-7 require an external discharge resistor?

No. The "D" suffix denotes integrated discharge functionality: a 35Ω internal NMOS transistor actively pulls the OUT pin to GND when EN is low. This eliminates the need for external resistors, reduces BOM count, and ensures consistent discharge timing (<100µs) across temperature and process variation.

Can AP7353D-36FS4-7 operate with input voltage below 3.6V?

Yes - minimum input is 2.0V, but dropout voltage must be satisfied. At 250mA load, dropout is up to 119mV; thus, VIN ≥ 3.719V is required to maintain regulated 3.6V output. For lower VIN, output voltage drops linearly (e.g., VIN = 3.5V yields ~3.38V output at full load).

How does the AP7353D-36FS4-7 respond to short-circuit conditions?

Under short-circuit (OUT-to-GND), the device limits output current to ~350mA and activates thermal shutdown if junction temperature exceeds +125°C. Recovery is automatic once fault clears and temperature falls below thermal hysteresis threshold - no latch-up or manual reset required.