Diodes Incorporated AP2111H-3.3TRG1

Overview

AP2111H-3.3TRG1 from BCD Semiconductor is a fixed-output 3.3V, 600mA CMOS low-dropout linear regulator in SOT-223 package with enable control, ±1.5% output accuracy, 250mV typical dropout at 600mA, and built-in auto-discharge function-designed for stable local regulation in portable computing power rails.

For engineers reviewing the AP2111H-3.3TRG1 datasheet, AP2111H-3.3TRG1 pinout, AP2111H-3.3TRG1 application, or AP2111H-3.3TRG1 equivalent, key selection criteria include dropout voltage under full load, PSRR at 1kHz, standby current, thermal shutdown threshold, and compatibility with 1.0μF ceramic output capacitors.

Technical Context

The AP2111H-3.3TRG1 implements a CMOS-based LDO architecture with internal voltage reference (0.8V), error amplifier, and PMOS pass transistor, enabling fast transient response and stable operation with minimal external components. Its enable logic (VIH ≥1.5V, VIL ≤0.4V) directly controls internal UVLO and shutdown circuitry.

Thermal protection activates at 160°C with 30°C hysteresis, and foldback short-circuit limiting caps fault current at 50mA. The device maintains regulation across -40°C to +85°C ambient and supports input voltages from 4.3V to 6.0V for 3.3V output.

Key Specifications

Pinout & Package

SOT-223 (H package) thermally enhanced 4-pin surface-mount package with exposed thermal pad; pin 1 = VIN, pin 2 = VOUT, pin 3 = GND, pin 4 = EN (active-high enable).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-3302E/TT and XC6206P332MR-G, the AP2111H-3.3TRG1 uniquely delivers 600mA output with enable control, auto-discharge, and 250mV dropout at full load-making it suitable for higher-power portable systems requiring precise power sequencing and fast fault recovery.

Availability

AP2111H-3.3TRG1 is available at Aetrix Electronics and suitable for laptop computer power management, portable DVD player subsystems, LCD monitor logic supplies, and industrial HMI panels requiring stable component supply across production lifecycles.

Supply support for AP2111H-3.3TRG1 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

BCD Semiconductor Manufacturing Limited is a China-based fabless analog IC designer specializing in power management, LED drivers, and interface solutions for consumer, industrial, and computing markets.

The AP2111 series targets cost-effective, high-reliability LDO applications in portable electronics, emphasizing low quiescent current, fast transient response, and broad capacitor compatibility without external compensation.

FAQ

What is the minimum input voltage required for AP2111H-3.3TRG1 to maintain regulation?

The AP2111H-3.3TRG1 requires a minimum input voltage of 4.3V to sustain 3.3V output at full 600mA load, based on its 250mV typical dropout specification. At lighter loads, regulation holds down to ~3.35V input, but design margin should preserve ≥4.3V under worst-case conditions including line and load regulation.

Does AP2111H-3.3TRG1 require an external capacitor on the ADJ pin?

No. The AP2111H-3.3TRG1 is a fixed-output variant; the ADJ pin is not present in this version. Only adjustable versions (e.g., AP2111K-ADJTRG1) use the ADJ pin for external feedback. This part uses internal resistor networks to set 3.3V output and has no ADJ terminal.

Can AP2111H-3.3TRG1 operate with a 10μF aluminum electrolytic output capacitor?

Yes. The datasheet explicitly confirms stability with 1.0μF ceramic, tantalum, and aluminum electrolytic capacitors. A 10μF aluminum electrolytic is acceptable and may improve low-frequency ripple rejection, provided ESR remains within 10–100mΩ per manufacturer guidance for LDO stability.

What happens to VOUT when EN is pulled low?

When EN is driven below 0.4V, the AP2111H-3.3TRG1 disables the pass transistor and activates an internal 60Ω discharge path from VOUT to GND. This actively pulls down the output capacitor voltage, achieving rapid discharge-critical for preventing back-powering or violating reset timing in multi-rail systems.