onsemi NCP139AFCT180T2G

Overview

NCP139AFCT180T2G from onsemi is a 1 A very low dropout (VLDO) linear regulator with NMOS pass transistor and separate bias rail (VBIAS), delivering ±1% output voltage accuracy over temperature and ultra-low 50 mV dropout at 1 A load. It features logic-level enable control, active output discharge, and stable operation with 10 µF ceramic output capacitors - designed for noise-sensitive, space-constrained portable applications such as smartphone core voltage rails.

For engineers reviewing the NCP139AFCT180T2G datasheet, pinout, applications, or equivalent options, key selection criteria include its fixed 1.8 V output, dual-rail architecture (VIN + VBIAS), thermal shutdown threshold (160°C), PSRR of 75 dB (VIN) and 85 dB (VBIAS) at 1 kHz, and WLCSP6 package compatibility with high-density PCB layouts.

Technical Context

The NCP139AFCT180T2G implements a dual-supply NMOS-based VLDO architecture where VIN supplies the power path and VBIAS (3.0–5.5 V) powers internal control circuitry independently - enabling optimized efficiency and stability in battery-powered systems. Its bias-input current is typ. 35 µA under load and drops to 0.5 µA in shutdown, supporting ultra-low quiescent power design.

Unlike PMOS LDOs, the NMOS topology decouples loop stability from output capacitor ESR, allowing robust performance with small 10 µF ceramic capacitors. The device integrates undervoltage lockout (UVLO) on VBIAS with 1.6 V threshold and 0.2 V hysteresis, plus monotonic startup and thermal shutdown (160°C activation / 140°C recovery) for system reliability.

Key Specifications

Pinout & Package

Package: WLCSP6 (1.2 mm × 0.8 mm, 0.4 mm pitch, Case 567MV) - ultra-compact chip-scale package optimized for high-density mobile PCBs with minimal board area and thermal resistance (R_JA = 69°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A2018PDQNR and BD3985FVM-TR, the NCP139AFCT180T2G uniquely combines 1 A capability, 50 mV dropout, dual-rail bias isolation, and 85 dB VBIAS PSRR - making it the only option capable of maintaining 1.8 V regulation under tight input headroom while rejecting noise from both power and bias domains.

Availability

NCP139AFCT180T2G is available at Aetrix Electronics and suitable for smartphone processor core rails, tablet memory I/O supplies, wireless camera module power, and DVR ISP rails requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for NCP139AFCT180T2G 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, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The NCP139AFCT180T2G belongs to onsemi's high-performance VLDO regulator product line, engineered specifically for noise-sensitive, space-constrained portable electronics requiring dual-rail operation and ultra-low dropout under 1 A loads.

FAQ

What is the output voltage of the NCP139AFCT180T2G?

The NCP139AFCT180T2G delivers a fixed 1.8 V output voltage with ±1.0% accuracy over −40°C to +85°C. This value is factory-trimmed and does not require external feedback components, simplifying design for dedicated 1.8 V rails in mobile processors and memory interfaces.

Does the NCP139AFCT180T2G require an external bias supply?

Yes, the NCP139AFCT180T2G requires a separate VBIAS supply between 3.0 V and 5.5 V to power its internal control circuitry. This bias rail is independent of VIN and enables superior PSRR (85 dB at 1 kHz) and stable operation even when VIN sags near VOUT.

What package type is used for the NCP139AFCT180T2G?

The NCP139AFCT180T2G uses the WLCSP6 package (1.2 mm × 0.8 mm, 0.4 mm pitch, Case 567MV), a wafer-level chip-scale package optimized for ultra-dense PCB layouts in smartphones and wearables, with R_JA = 69°C/W under JEDEC-standard test conditions.

Does the NCP139AFCT180T2G include active output discharge?

Yes, the NCP139AFCT180T2G includes integrated active output discharge (a feature of the "A" variant), providing a 150 Ω pull-down path from VOUT to GND when EN is low - ensuring rapid discharge of output capacitance for safe power sequencing in multi-rail systems.

What is the minimum input voltage required for full 1 A operation of the NCP139AFCT180T2G?

For full 1 A output at 1.8 V, the NCP139AFCT180T2G requires VIN ≥ 1.85 V (VOUT + 50 mV typ. dropout). At lower VIN, current capability degrades per the dropout curve in Figure 3 of the datasheet; operation below 1.85 V is possible but limited to reduced load currents.