Diodes Incorporated AP7361-33E-13

Overview

AP7361-33E-13 from Diodes Incorporated is a 1A fixed-output (3.3V) ultra-low dropout linear regulator in SOT223 package with enable control, 70µA typical quiescent current, 500mV dropout at 1A load, and thermal shutdown protection. It delivers stable power to FPGA I/O rails, laptop subsystems, and battery-powered audio devices requiring precise low-noise voltage regulation.

For engineers reviewing the AP7361-33E-13 datasheet, AP7361-33E-13 pinout, AP7361-33E-13 application, or AP7361-33E-13 equivalent, key selection criteria include dropout voltage at full load, EN pin logic thresholds, thermal resistance (θ_JA = 110°C/W), output accuracy (±2% over temperature), and ceramic capacitor compatibility (≥2.2µF).

Technical Context

The AP7361-33E-13 integrates a PMOS pass element, precision 0.8V bandgap reference, and error amplifier for fixed 3.3V output regulation. Its architecture supports fast transient response (<200µs start-up) and high PSRR (65dB @ 1kHz) without requiring external compensation.

Enable functionality is implemented via a TTL/CMOS-compatible EN pin (VIH = 1.0V, VIL = 0.3V), while built-in current limiting (1.1–1.5A) and thermal shutdown (150°C trip, 20°C hysteresis) provide fault protection independent of external circuitry.

Key Specifications

Pinout & Package

SOT223 package (3-pin variant, pin 1 = IN, pin 2 = GND, pin 3 = OUT) with exposed thermal pad (pin 3 connected internally to GND in this configuration per datasheet Figure 1). Requires minimum 2.2µF ceramic output capacitor and 1µF input capacitor for stability.

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 TPS7A2033PDBVR, the AP7361-33E-13 uniquely balances 1A capability, 500mV dropout, and 70µA IQ in a thermally robust SOT223 package - making it the only viable choice for mid-power digital subsystems needing both current headroom and battery longevity.

Availability

AP7361-33E-13 is available at Aetrix Electronics and suitable for FPGA I/O power, laptop subsystem rails, and battery-powered audio devices requiring stable component supply with guaranteed long-term manufacturability.

Supply support for AP7361-33E-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 manufacturer specializing in discrete, analog, and mixed-signal solutions for power management, signal integrity, and connectivity applications.

The AP7361 belongs to Diodes' high-performance LDO regulator product line, designed specifically for power-constrained digital systems requiring low dropout, fast transient response, and integrated fault protection.

FAQ

What is the maximum allowable input voltage for AP7361-33E-13?

The absolute maximum input voltage is 6.5V, but the recommended operating range is 2.2V to 6.0V. Exceeding 6.0V risks violating the device's safe operating area, especially under high ambient temperatures or heavy load conditions where power dissipation increases. Operation above 6.0V may trigger internal protection or cause premature failure.

Can AP7361-33E-13 be used without an enable signal?

Yes - the EN pin can be tied directly to the IN pin to maintain continuous operation. This configuration disables the enable function but preserves all regulation and protection features. Do not leave EN floating, as undefined logic levels may cause erratic turn-on behavior or increased leakage current.

Is a minimum load required for output stability?

No minimum load is required. The AP7361-33E-13 remains stable and fully regulated from zero load up to 1A, as confirmed in the datasheet's "No Load Stability" section. This eliminates the need for dummy loads in standby or sleep modes, improving system efficiency.

What thermal considerations apply to the SOT223 package?

The SOT223 package has θ_JA = 110°C/W. To avoid thermal shutdown at 1A load with 3.8V input (500mW dissipation), the PCB must provide ≥1.5cm² copper pour connected to the thermal pad. Ambient temperature must stay below +70°C for continuous 1A operation; derating is required above that threshold.