onsemi NCP1117DT25G

Overview

NCP1117DT25G from onsemi is a 2.5 V fixed-output, low-dropout linear voltage regulator in DPAK package, delivering up to 1.0 A output current with 1.2 V max dropout at 800 mA and ±1.0% output voltage accuracy over temperature. It operates from 3.9 V to 10 V input, requires no minimum load, and integrates thermal shutdown, current limiting, and safe operating area protection - used in hard drive controllers and switching power supply post-regulation.

For engineers reviewing the NCP1117DT25G datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage at full load, thermal performance in DPAK layout, line/load regulation specs (≤0.5% / ≤4.3 mV), and compatibility with 10 µF ceramic output capacitance for stability.

Technical Context

The NCP1117DT25G implements a bandgap-referenced series pass architecture with internal trimming for ±1.0% initial output accuracy and 0.5% temperature stability. Its dropout behavior is characterized across −40°C to +125°C ambient, maintaining regulation down to Vin = Vout + 1.2 V at 800 mA.

Protection circuitry includes foldback current limiting activated above ~1.5 A, thermal shutdown triggered at ~175°C junction temperature, and safe operating area compensation to prevent secondary breakdown during transient overload. Input voltage range is specified up to 20 V, but for 2.5 V output, valid operating input is 3.9 V to 10 V per electrical characteristics table.

Key Specifications

Pinout & Package

DPAK (Case 369C) surface-mount package with exposed metal tab thermally connected to Pin 2 (Output). Tab serves as primary heatsink path to PCB copper.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MIC29302WU-2.5 and TLV1117-25IDCYR, the NCP1117DT25G offers optimal balance of 1.0 A capability, 1.2 V dropout, and DPAK thermal performance for 2.5 V point-of-load regulation - especially where input is 3.9–10 V and board-level heatsinking is implemented via the exposed tab.

Availability

NCP1117DT25G is available at Aetrix Electronics and suitable for hard drive controllers, switching power supply post-regulation, and consumer equipment point-of-load applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for NCP1117DT25G 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 focused on energy-efficient electronics, with leadership in power management, analog, and sensor technologies.

The NCP1117 series was designed for high-reliability, low-dropout linear regulation in industrial and computing applications - emphasizing thermal robustness, precision output, and seamless replacement of legacy LM317-based designs.

FAQ

What is the maximum input voltage for NCP1117DT25G?

The absolute maximum input voltage for NCP1117DT25G is 20 V, but its specified operating input range for 2.5 V output is 3.9 V to 10 V. Exceeding 10 V may cause excessive power dissipation and thermal stress unless heatsinking is significantly enhanced. The device's internal protection prevents damage, but sustained operation above 10 V is not recommended for reliability.

Does NCP1117DT25G require an output capacitor, and what type is recommended?

Yes, NCP1117DT25G requires a minimum 4.7 µF output capacitor with ESR between 33 mΩ and 2.2 Ω for stability. A 10 µF ceramic capacitor is recommended and widely used. Tantalum or aluminum electrolytic types are acceptable if they meet the ESR and capacitance specifications across the full operating temperature range.

Is NCP1117DT25G pin-compatible with the LM317?

No - NCP1117DT25G is a fixed-output 2.5 V regulator in DPAK-3 package with pinout (1=GND, 2=OUT, 3=IN), whereas the LM317 is adjustable and uses a different pin assignment (1=ADJ, 2=OUT, 3=IN). However, the NCP1117 series is functionally and footprint-compatible with LM317-based designs only when using the adjustable variant (NCP1117DTAG) in SOT-223 or DPAK packages.

What thermal performance can be expected from NCP1117DT25G in DPAK package?

In DPAK (Case 369C), NCP1117DT25G has R_θJA ≈ 67°C/W (minimum pad) and R_θJC = 6.0°C/W. With 2 oz. copper and 25 mm² thermal pad, typical R_θJA is ~40°C/W. At 1.0 A and 1.2 V dropout (1.2 W dissipation), junction-to-ambient rise is ~48°C - well below the 150°C max rating when ambient is ≤85°C.

Does NCP1117DT25G have built-in reverse-voltage or reverse-current protection?

No, NCP1117DT25G does not include reverse-voltage or reverse-current protection. It contains two internal diode paths (V_OUT→V_IN and C_ADJ→V_OUT) rated for 15 A and 150 mA surge respectively, but these are not intended as protection features. External diodes (e.g., 1N4001) are required if V_IN may be shorted to ground while output capacitors remain charged.