Diodes Incorporated AP7361C-33SP-13

Overview

AP7361C-33SP-13 from Diodes Incorporated is a 1A fixed-output (3.3V), ultra-low dropout linear regulator with enable pin, designed for power rail regulation in space-constrained applications. It delivers ±1% output voltage accuracy, 360mV dropout at 1A (3.3V output), 60µA typical quiescent current, and integrates thermal shutdown, fold-back short-circuit protection (400mA), and 1.5A current limiting. It is used in LCD-TV power supplies where stable 3.3V biasing is required for display controllers.

For engineers reviewing the AP7361C-33SP-13 datasheet, AP7361C-33SP-13 pinout, AP7361C-33SP-13 application, or AP7361C-33SP-13 equivalent, key selection criteria include dropout performance at full load, EN logic thresholds (VIH = 1.0V min, VIL = 0.3V max), SO-8EP thermal resistance (100°C/W), stability with ≥2.2µF MLCC output capacitors, and compatibility with 2.2–6.0V input rails.

Technical Context

The AP7361C-33SP-13 implements a PMOS pass transistor architecture enabling ultra-low dropout operation and high PSRR (75dB @ 1kHz). Its internal 0.8V bandgap reference feeds an error amplifier that regulates output via feedback from the fixed 3.3V divider network embedded in the die.

Enable control is implemented as a logic-high active input (EN) with 3.0MΩ internal pull-down; the SO-8EP package supports full ON/OFF functionality. Protection circuitry includes fold-back current limiting triggered at ~400mA during short-circuit events and thermal shutdown activation at 150°C with 20°C hysteresis.

Key Specifications

Pinout & Package

AP7361C-33SP-13 is packaged in SO-8EP (exposed pad), a thermally enhanced 8-pin surface-mount package with GND-connected thermal pad on underside. Pin 1 is IN; Pin 2 is GND; Pin 3 is OUT; Pin 4 is GND; Pin 5 is EN; Pin 6 is NC; Pin 7 is NC; Pin 8 is GND.

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 TLS850F3TAV50, AP7361C-33SP-13 uniquely balances 1A output, SO-8EP thermal performance, and enable functionality at consumer-grade cost-making it optimal for mid-power industrial and consumer displays requiring precise 3.3V regulation with power gating.

Availability

AP7361C-33SP-13 is available at Aetrix Electronics and suitable for LCD-TV mainboards, set-top box power trees, and home appliance control panels requiring stable component supply, long-term manufacturability, and RoHS-compliant packaging.

Supply support for AP7361C-33SP-13 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 manufacturing certified to IATF16949:2016 and environmental compliance to RoHS 3 and halogen-free standards.

The AP7361C belongs to Diodes' high-performance LDO portfolio targeting consumer, industrial, and computing applications where low dropout, low IQ, and robust protection are essential for reliable power delivery.

FAQ

What is the minimum input voltage required for AP7361C-33SP-13 to maintain regulation at 1A load?

The minimum input voltage is calculated as VOUT + VDROPOUT = 3.3V + 0.36V = 3.66V under typical conditions. At worst-case (max dropout), 3.3V + 0.44V = 3.74V applies per datasheet Table 2 for 3.3V output at 1A. Input must remain ≥3.74V to guarantee regulation across temperature and process variation.

Can AP7361C-33SP-13 operate without an output capacitor?

No. The device requires a minimum 2.2µF ceramic capacitor between OUT and GND for stability, as confirmed in Section 10 of the datasheet. Omitting it causes oscillation and potential damage. Larger values improve transient response but are not mandatory beyond 2.2µF.

Is the EN pin internally pulled down on AP7361C-33SP-13?

Yes. The EN pin has a 3.0MΩ internal pull-down resistor (RENPD), ensuring the regulator remains disabled by default if left floating. This eliminates need for external pull-down in most designs, though tying EN directly to IN is recommended if enable control is unused.

Does AP7361C-33SP-13 require a minimum load current to maintain regulation?

No. The datasheet explicitly states "no minimum load is required to keep the device stable" (Section 11). It remains regulated and stable from zero load up to 1A, making it suitable for systems with highly variable or intermittent current draw.