onsemi NCP1117DT285RKG

Overview

NCP1117DT285RKG from onsemi is a 2.85 V fixed-output, 1.0 A low-dropout linear voltage regulator in DPAK (TO-252) package, featuring 1.2 V max dropout at 800 mA, ±1.0% output voltage accuracy, and integrated thermal shutdown, current limiting, and safe operating area protection. It enables stable point-of-load regulation in SCSI termination and hard drive controller power rails.

For engineers reviewing the NCP1117DT285RKG datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage at 800 mA, load regulation ≤3.8 mV, ripple rejection ≥62 dB at 120 Hz, thermal resistance (R_JA = 67°C/W min pad), and compatibility with 4.7 µF–10 µF output capacitors with ESR 33 mΩ–2.2 Ω.

Technical Context

The NCP1117DT285RKG operates as a three-terminal fixed-output LDO with internal bandgap reference trimmed to ±1.0%, delivering regulated 2.85 V across 0–800 mA load current without minimum load requirement. Its architecture includes a PNP pass transistor, precision error amplifier, and thermal foldback circuitry that activates at ~175°C junction temperature.

It supports input voltages up to 20 V and maintains regulation over ambient temperatures from 0°C to +125°C. The device requires no external compensation and achieves stability with a single 10 µF output capacitor meeting ESR constraints-enabling robust transient response in post-regulation and battery-charger applications.

Key Specifications

Pinout & Package

DPAK (TO-252-3) package with exposed metal tab thermally and electrically connected to Pin 2 (Output). Standard 3-pin surface-mount outline measuring 6.10 × 6.54 × 2.28 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV1117-285CDR and LD1086DT285TR, the NCP1117DT285RKG delivers superior thermal performance (67°C/W vs. 160°C/W), tighter output accuracy (±1.0% vs. ±2%), and lower dropout (1.2 V vs. 1.5 V), making it optimal for high-reliability SCSI termination and HDD controller designs where thermal headroom and voltage precision are critical.

Availability

NCP1117DT285RKG is available at Aetrix Electronics and suitable for active SCSI termination, hard drive controller power, and switching power supply post-regulation requiring stable component supply, RoHS-compliant packaging, and automotive-grade traceability.

Supply support for NCP1117DT285RKG 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, and sensing solutions for automotive, industrial, and consumer markets.

The NCP1117 series was designed specifically for high-current, low-dropout point-of-load regulation in cost-sensitive industrial and computing applications-emphasizing thermal robustness, ±1.0% accuracy, and compatibility with legacy LM317 footprints.

FAQ

What is the maximum input voltage rating for the NCP1117DT285RKG?

The NCP1117DT285RKG has an absolute maximum input voltage rating of 20 V, as specified in the Absolute Maximum Ratings table. Operation beyond this voltage risks permanent damage. For reliable long-term use, the recommended maximum continuous input is 18 V, especially under high ambient temperature or high load conditions where power dissipation increases significantly.

Does the NCP1117DT285RKG require an external capacitor on the adjust pin?

No-the NCP1117DT285RKG is a fixed-output variant and does not have an adjustable pin; Pin 1 serves solely as ground. External capacitors are required only on the input (10 µF ceramic/tantalum) and output (≥4.7 µF with ESR 33 mΩ–2.2 Ω) to ensure stability and transient response. The adjust pin capacitor (C_adj) applies only to the adjustable NCP1117DTAG version.

What is the thermal shutdown threshold temperature for the NCP1117DT285RKG?

The NCP1117DT285RKG activates thermal shutdown at approximately 175°C junction temperature, as confirmed in the datasheet's "Thermal Considerations" section. Once triggered, the output disables until the die cools below the hysteresis threshold (~150°C), preventing catastrophic failure. This feature is not a substitute for proper PCB copper heatsinking-especially critical given its 67°C/W R_JA with minimum pad.

Can the NCP1117DT285RKG be used in automotive applications?

The NCP1117DT285RKG is rated for 0°C to +125°C ambient operation but is not AEC-Q100 qualified. For automotive applications requiring qualification, the functionally identical NCV1117DT285RKG (AEC-Q100 Grade 1, –40°C to +125°C) should be selected instead. Both share identical electrical specs and DPAK packaging, but only the NCV prefix guarantees automotive process controls and PPAP documentation.

What is the typical quiescent current of the NCP1117DT285RKG at 10 V input?

At 10 V input and 25°C ambient, the NCP1117DT285RKG draws a typical quiescent current of 5.5 mA, as listed in the Electrical Characteristics table under "Quiescent Current" for the 2.85 V fixed version. This value remains stable across load conditions and contributes minimally to total system power loss-making it suitable for always-on subsystems in storage and industrial controllers.