Diodes Incorporated AP1118D50L-13

Overview

AP1118D50L-13 from Anachip Corp. is a 1A positive low-dropout linear regulator with fixed 5.0V output, TTL/CMOS-compatible enable function, and 1.4V maximum dropout at full load. It delivers stable voltage for low-voltage ICs in high-speed bus termination and 3.3V logic supply systems, and is packaged in lead-free TO252-5L.

For engineers reviewing the AP1118D50L-13 datasheet, AP1118D50L-13 pinout, AP1118D50L-13 application, or AP1118D50L-13 equivalent, key selection criteria include dropout voltage under 1.4V at 1A, thermal shutdown protection, ±2% output voltage tolerance at 10mA, EN pin logic compatibility, and TO252-5L thermal resistance of 102°C/W (junction-to-ambient, no heatsink).

Technical Context

The AP1118D50L-13 employs a PNP pass transistor architecture with internal current limiting and thermal shutdown circuitry. Its enable input features an internal ~100kΩ pull-down resistor, ensuring default-on operation when left floating.

Designed for low-noise, low-transient applications, it achieves 70dB ripple rejection at 120Hz with 25µF tantalum output capacitance and maintains regulation with input as low as VOUT + 1.3V - enabling use with 6.5V–15V input supplies for 5.0V output.

Key Specifications

Pinout & Package

AP1118D50L-13 uses the TO252-5L (DPAK-5) surface-mount package with exposed thermal pad. The tab is electrically connected to VOUT and serves as primary heat path.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LD1117S50TR and MIC29302WU, AP1118D50L-13 uniquely balances 1A capability, 1.4V dropout, EN control, and compact TO252-5L thermal performance - making it optimal for cost- and space-constrained 5V peripheral rails where precise sequencing and moderate input range are required.

Availability

AP1118D50L-13 is available at Aetrix Electronics and suitable for PC peripheral power, communication interface supply, and optical drive controller applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AP1118D50L-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

Anachip Corp. is a Taiwan-based semiconductor company specializing in analog and mixed-signal power management ICs since 1997, with focus on LDOs, DC/DC converters, and LED drivers.

The AP1118 product line targets cost-sensitive, high-volume embedded systems requiring reliable fixed-output regulation with enable control and robust thermal protection - especially in PC, optical storage, and industrial interface applications.

FAQ

What is the minimum input voltage required for AP1118D50L-13 to regulate 5.0V output?

The device requires Vin ≥ VOUT + 1.3V to maintain regulation, so minimum valid input is 6.3V. At 1A load, dropout is guaranteed ≤1.4V, meaning 6.5V is the practical minimum for full-load operation across temperature. Input below this causes output to track input (dropout mode).

Can the NC pin on AP1118D50L-13 be grounded or left floating?

The NC pin is not internally bonded and must remain unconnected. Grounding or routing it to any net risks parasitic coupling or instability due to proximity to sensitive control nodes. Datasheet explicitly states "Not Recommended" for any connection - floating is the only compliant configuration.

Does AP1118D50L-13 require an input capacitor, and if so, what value?

Yes - a minimum 100µF low-ESR electrolytic or tantalum capacitor is required between Vin and GND. This prevents input voltage sag during 1A load transients and ensures stable loop response. Smaller ceramics (<10µF) alone are insufficient; bulk capacitance is mandatory per typical application circuit.

How does the EN pin behave when left unconnected?

With internal ~100kΩ pull-down resistor, an open EN pin defaults to logic low (~0V), enabling the output. This allows simple on/off control: tie to MCU GPIO for active-low enable, or leave floating for always-on operation - no external pull-down needed unless noise immunity is critical.