Diodes Incorporated AP7353-31FS4-7

Overview

AP7353-31FS4-7 from Diodes Incorporated is a 250mA low-dropout linear regulator with fixed 3.1V output, ±1% accuracy, 90dB PSRR at 1kHz, 10µV_rms output noise (10Hz–100kHz), and 18µA typical quiescent current. It uses a CMOS process, features enable control, thermal shutdown, and short-circuit protection, and is optimized for RF supply rails in portable communication devices.

For engineers reviewing the AP7353-31FS4-7 datasheet, AP7353-31FS4-7 pinout, AP7353-31FS4-7 application, or AP7353-31FS4-7 equivalent, key selection criteria include dropout voltage at 250mA (68–147mV), load transient response stability with 1µF ceramic output capacitance, EN logic thresholds (0.4V_IL/1.2V_IH), and thermal resistance (237°C/W) in the X2-DFN1010-4 package.

Technical Context

The AP7353-31FS4-7 integrates a precision voltage reference, error amplifier, current-limit circuit, and CMOS pass transistor - enabling high PSRR and low-noise regulation without external compensation. Its non-discharge architecture avoids automatic output discharge during shutdown, preserving downstream capacitor charge.

It operates across 2.0V–5.5V input range with 3.1V fixed output, supports fast load transients (20µs response to 1mA→250mA step), and maintains ±1% output accuracy over –40°C to +85°C ambient temperature and full 0–250mA load range.

Key Specifications

Pinout & Package

AP7353-31FS4-7 is packaged in the X2-DFN1010-4 (Type B) - a 1.0mm × 1.0mm, 0.4mm pitch, 4-terminal leadless package with exposed thermal pad (EP). The package supports high-density PCB layouts and provides 237°C/W junction-to-ambient thermal resistance under JEDEC High-K board conditions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B312MR-G and RT9080A-31PU5, AP7353-31FS4-7 delivers superior PSRR and lower noise in the same 1.0mm × 1.0mm footprint - making it optimal for space-constrained, high-frequency-sensitive designs where supply integrity directly impacts RF performance metrics.

Availability

AP7353-31FS4-7 is available at Aetrix Electronics and suitable for smartphone baseband power, RF front-end bias, and wearable sensor hub applications requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant green packaging.

Supply support for AP7353-31FS4-7 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 power management, signal integrity, and connectivity solutions for consumer, industrial, and automotive markets.

The AP7353 series belongs to Diodes' high-PSRR, low-noise LDO product line - engineered specifically for noise-sensitive portable electronics where battery efficiency, small form factor, and RF supply cleanliness are critical design requirements.

FAQ

What is the minimum input voltage required for AP7353-31FS4-7 to maintain 3.1V output at 250mA?

The dropout voltage is specified as 68–147mV at 250mA and 3.1V output. Therefore, the minimum input voltage is 3.1V + 0.147V = 3.247V under worst-case conditions. For reliable operation across temperature and process variation, a minimum VIN of 3.3V is recommended.

Can AP7353-31FS4-7 be used with ceramic capacitors smaller than 1µF?

The datasheet specifies a minimum effective capacitance of 0.7µF to maintain stability, accounting for DC bias, temperature, and tolerance derating. A 1µF X7R ceramic capacitor is recommended; using a 0.82µF part may be acceptable if its actual capacitance remains ≥0.7µF under operating bias and temperature, verified by vendor SPICE models or bench testing.

Does AP7353-31FS4-7 include reverse-current protection?

No. The AP7353-31FS4-7 does not integrate reverse-current blocking. When the output voltage exceeds the input (e.g., during hot-swap or backup battery scenarios), current can flow from OUT to IN through the internal pass transistor's body diode. An external Schottky diode in series with IN is required for reverse-current isolation.

Is the exposed thermal pad (EP) electrically connected to GND internally?

No. The EP is not internally connected to any pin; it serves only as a thermal conduction path. Per the datasheet, it should be connected to PCB ground plane for thermal performance - but must not be used as the sole GND electrode. The dedicated Pin 2 (GND) remains the primary signal ground reference.