onsemi NCP5661MN15T2G

Overview

NCP5661MN15T2G from onsemi is a fixed-output, 1.5 V, 1.0 A ultra-low-dropout linear regulator in a thermally robust DFN6 3×3.3 mm package. It delivers ultra-fast transient response (1–3 µs settling), low ground current (≤3.0 mA at 1.0 A), and 26 µV_rms output noise without bypass capacitor-ideal for post-regulation in high-performance ASIC power supplies.

For engineers reviewing the NCP5661MN15T2G datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage ≤1.3 V at 1.0 A, ±1% output accuracy over −40°C to +125°C, Error Flag functionality for 1.5 V output, and compatibility with low-ESR ceramic output capacitors ≥10 µF.

Technical Context

The NCP5661MN15T2G integrates a 0.9 V internal reference and precision error amplifier to regulate its fixed 1.5 V output. Its architecture maintains low ground current independent of load and achieves >65 dB ripple rejection at 1 kHz-critical for noise-sensitive digital loads like FPGAs and SoCs.

It features integrated thermal shutdown (160°C) and current limiting (1.5 A peak), with an active-low Error Flag (Pin 5) that asserts logic low when output falls below 88% of nominal (1.32 V), requiring only a 100 kΩ external pullup resistor for system fault monitoring.

Key Specifications

Pinout & Package

Package: DFN6 3.0×3.3 mm, 0.95 mm pitch, exposed thermal pad (EPAD) connected to Pin 3 (GND) for enhanced thermal dissipation (R_θJA = 82°C/W with 1 in² copper).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A4700RGWR and BD3572FP-E2, the NCP5661MN15T2G uniquely combines fixed 1.5 V output, ±1% accuracy, ultra-fast transient response, and integrated Error Flag in a thermally optimized DFN6-making it optimal for high-reliability, space-constrained digital power rails requiring real-time fault visibility.

Availability

NCP5661MN15T2G is available at Aetrix Electronics and suitable for server power supplies, ASIC core regulation, and networking equipment requiring stable component supply, long-term lifecycle support, and Pb-free compliance.

Supply support for NCP5661MN15T2G 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 cloud infrastructure markets.

The NCP5661 series was designed specifically for high-current, low-noise point-of-load regulation in demanding digital systems-including servers, networking gear, and high-end consumer electronics-where thermal efficiency and transient immunity are critical.

FAQ

What is the maximum input voltage rating for the NCP5661MN15T2G?

The NCP5661MN15T2G has an absolute maximum input voltage (Vin) rating of 18 V. However, for reliable continuous operation, the recommended input voltage range is 2.0 V to 9.0 V per electrical characteristics. Exceeding 9.0 V may increase power dissipation and thermal stress without improving regulation performance.

Does the NCP5661MN15T2G require an external bypass capacitor for low-noise operation?

No, the NCP5661MN15T2G achieves 26 µV_rms output noise (10 Hz–100 kHz) without any external bypass capacitor. This eliminates a common BOM item and simplifies layout-though a 150 µF input capacitor and ≥10 µF low-ESR ceramic output capacitor are still required for stability and transient response.

How does the Error Flag function on the NCP5661MN15T2G?

The Error Flag (Pin 5) is an open-drain output that pulls low when the regulated 1.5 V output drops below 88% (1.32 V). It includes 50 µs blanking time to ignore brief transients. A 100 kΩ pullup resistor to Vin is required; the NCP5661MN15T2G does not drive high-only sinks current during fault conditions.

What thermal performance can be expected from the NCP5661MN15T2G in a standard PCB layout?

With 1 in² of 1 oz copper connected to the EPAD (Pin 3), the NCP5661MN15T2G achieves R_θJA = 82°C/W. At 1.0 A load and 1.0 V dropout, power dissipation is ~1.0 W, resulting in ~82°C junction-to-ambient rise-well within its −40°C to +150°C operating range when ambient is ≤68°C.

Is the NCP5661MN15T2G pin-compatible with other variants in the NCP5661 family?

Yes-the NCP5661MN15T2G shares identical DFN6 3×3.3 mm pinout and footprint with all NCP5661MNxT2G variants (e.g., 1.2 V, 1.8 V, 2.5 V). Only the output voltage and marking differ; no PCB redesign is needed when swapping fixed-output versions, provided input/output capacitor values meet each variant's stability requirements.