Diodes Incorporated AP7361C-33FGE-7

Overview

AP7361C-33FGE-7 from Diodes Incorporated is a 1A fixed-output (3.3V), ultra-low dropout linear regulator in U-DFN3030-8 (Type E) package with enable control, ±1% output accuracy, 360mV dropout at 1A, and 60µA quiescent current-designed for stable power delivery in space-constrained portable electronics such as USB-powered audio interfaces and battery-backed IoT sensor nodes.

For engineers reviewing the AP7361C-33FGE-7 datasheet, AP7361C-33FGE-7 pinout, AP7361C-33FGE-7 application, or AP7361C-33FGE-7 equivalent, key selection criteria include dropout voltage at full load, thermal resistance (θ_JA = 70°C/W), EN logic thresholds (V_IL ≤ 0.3V, V_IH ≥ 1.0V), and compatibility with 2.2µF MLCC output capacitors without external compensation.

Technical Context

The AP7361C-33FGE-7 integrates a PMOS pass element, precision 0.8V bandgap reference, and error amplifier to regulate output within ±1% across -40°C to +85°C ambient. Its fold-back short-circuit protection limits output current to 400mA during fault conditions, while thermal shutdown activates at ~150°C with 20°C hysteresis.

It operates from 2.2V to 6.0V input, supports fast start-up (~150µs), delivers 75dB PSRR at 1kHz, and remains stable with ≥2.2µF ceramic output capacitance-enabling direct replacement of legacy LDOs in noise-sensitive analog supply rails without redesigning compensation networks.

Key Specifications

Pinout & Package

U-DFN3030-8 (Type E) package with exposed thermal pad (pin 8 = GND); 0.5mm pitch, 3.0mm × 3.0mm footprint, moisture sensitivity level 1 per J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-3302E/TO and XC6210B332MR-G, the AP7361C-33FGE-7 delivers superior thermal performance (70°C/W vs. >200°C/W), tighter output accuracy (±1% vs. ±2%), and lower dropout-making it optimal for thermally constrained, high-precision 1A applications where reliability under sustained load is critical.

Availability

AP7361C-33FGE-7 is available at Aetrix Electronics and suitable for USB-powered audio interfaces, IoT sensor nodes, set-top box HDMI PHY supplies, and portable medical devices requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for AP7361C-33FGE-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 solutions for power management, signal integrity, and connectivity applications.

The AP7361C belongs to Diodes' high-performance LDO family designed for low-noise, low-dropout power delivery in portable, battery-operated, and space-constrained systems demanding precision regulation and robust fault protection.

FAQ

What is the minimum input voltage required for AP7361C-33FGE-7 to maintain regulation at 1A load?

The minimum input voltage is calculated as V_OUT + V_DROPOUT = 3.3V + 0.36V = 3.66V. At 1A load and +25°C, regulation is maintained down to 3.66V input; at higher temperatures or worst-case tolerance, 3.75V is recommended for margin. Below this, output voltage drops nonlinearly.

Can AP7361C-33FGE-7 operate without an external output capacitor?

No. The device requires ≥2.2µF ceramic output capacitance for stability, as confirmed in the datasheet's "Output Capacitor" section. Omitting C_OUT causes oscillation and potential damage. MLCC, solid polymer, or low-ESR electrolytic types are acceptable-no series resistor needed.

Is the EN pin internally pulled up, and what happens if left floating?

Yes-the EN pin has a 3.0MΩ internal pull-down resistor (R_ENPD). If left floating, it defaults to logic low, disabling the regulator. To enable, connect EN directly to IN or drive with a GPIO ≥1.0V. Floating EN is not a valid operating condition.

How does thermal performance differ between U-DFN3030-8 and SO-8EP packages for AP7361C-33?

U-DFN3030-8 achieves θ_JA = 70°C/W with proper thermal vias to ground plane, while SO-8EP is rated at 100°C/W. This 30°C/W difference means the U-DFN package dissipates the same 0.5W power with 15°C lower junction rise-critical for compact enclosures without forced airflow.