onsemi NCP1086D2T-ADJR4

Overview

NCP1086D2T-ADJR4 from onsemi is an adjustable-output linear voltage regulator delivering up to 1.5 A with ±1% output accuracy over temperature, 1.05 V typical dropout at full load, fast transient response, and integrated overcurrent and thermal shutdown protection. It serves as a post-regulator or microprocessor supply in low-voltage, high-transient-demand systems such as embedded controllers and industrial power rails.

For engineers reviewing the NCP1086D2T-ADJR4 datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage at 1.5 A, reference voltage stability (1.254 V typ), thermal regulation (0.002 %/W), minimum load current (0.6 mA), and compatibility with tantalum output capacitors for stability.

Technical Context

The NCP1086D2T-ADJR4 uses a composite PNP–NPN pass transistor architecture optimized for low dropout and fast loop response. Its internal bandgap reference maintains 1.254 V between VOUT and ADJ pins, enabling precise external resistor-divider programming of output voltage from 1.25 V to 5.5 V.

Protection circuitry includes foldback current limiting (1.6–3.1 A) and thermal shutdown triggered at 150–210 °C with 25 °C hysteresis. The device operates with input-to-output differential up to 7.0 V and requires ≥22 µF tantalum output capacitance for stable operation under 1.5 A load transients.

Key Specifications

Pinout & Package

The NCP1086D2T-ADJR4 is housed in a D2PAK−3 (TO−263) surface-mount package with exposed thermal pad (Case 418AB), rated for R_JC = 3.5 °C/W. Pin 1 is Adj, Pin 2 is VOUT (connected to tab), and Pin 3 is VIN.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LT1086CM-3.3#PBF and TLV1117-33CDCYR, the NCP1086D2T-ADJR4 delivers superior dropout performance (1.05 V vs. 1.3 V/1.2 V), tighter output accuracy (±1% vs. ±1.5%/±2%), and D2PAK thermal capability (R_JC = 3.5 °C/W) essential for sustained 1.5 A operation in industrial enclosures.

Availability

NCP1086D2T-ADJR4 is available at Aetrix Electronics and suitable for industrial PLC I/O power, embedded controller core supply, and medical diagnostic sensor bias requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for NCP1086D2T-ADJR4 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, sensors, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The NCP1086 series was designed specifically for high-current, low-dropout post-regulation in microprocessor and FPGA power domains where fast transient response and thermal robustness are critical.

FAQ

What output voltage range does the NCP1086D2T-ADJR4 support?

The NCP1086D2T-ADJR4 supports an adjustable output voltage range of 1.25 V to 5.5 V, set externally using two resistors (R1 and R2) per the formula V_OUT = 1.25 × (1 + R1/R2) + I_Adj × R2. Its internal 1.254 V reference ensures ±1% accuracy over temperature, making it suitable for precision applications like sensor biasing and reference rails where fixed-output variants lack flexibility.

Does the NCP1086D2T-ADJR4 require an external capacitor for stability?

Yes, the NCP1086D2T-ADJR4 requires a minimum 22 µF tantalum output capacitor for guaranteed stability under full 1.5 A load conditions. Aluminum electrolytic capacitors are also acceptable, but ceramic or film capacitors with near-zero ESR may cause oscillation. The capacitor must be placed close to the VOUT and GND pins, and for microprocessor applications, a parallel network of tantalum and ceramic capacitors is recommended to reduce effective ESR and improve transient response.

What thermal considerations apply to the NCP1086D2T-ADJR4 in continuous 1.5 A operation?

In continuous 1.5 A operation, the NCP1086D2T-ADJR4's D2PAK−3 package has a junction-to-case thermal resistance (R_JC) of 3.5 °C/W. With a typical 1.05 V dropout, power dissipation reaches ~1.58 W. To maintain TJ ≤ 150 °C at 70 °C ambient, total R_JA must be ≤ 50.6 °C/W - achievable with a modest heatsink and thermal compound. Without heatsinking, R_JA ≈ 10–50 °C/W depending on PCB copper area, so derating or forced airflow may be necessary for sustained full-load operation.

How does the NCP1086D2T-ADJR4 handle short-circuit conditions?

The NCP1086D2T-ADJR4 incorporates foldback current limiting (1.6–3.1 A) and thermal shutdown (150–210 °C) to protect against short circuits. However, during high-VIN short circuits (e.g., VIN > VOUT + 7.0 V), the pass transistor can exceed safe operating area before protection activates. For fail-safe operation, external clamping circuitry - such as a Zener diode between VIN and VOUT - is recommended to limit the VIN–VOUT differential to ≤7.0 V, preventing destructive failure.

Is the NCP1086D2T-ADJR4 pin-compatible with other regulators?

Yes, the NCP1086D2T-ADJR4 is explicitly pin-compatible with the LT1086 family of adjustable linear regulators in D2PAK−3, TO−220−3, and SOT−223 packages. This allows drop-in replacement in existing designs, though its lower 1.05 V typical dropout and tighter ±1% output accuracy provide measurable performance improvements over LT1086 variants in thermally constrained or low-margin applications.