onsemi NCP139AFCTC06ADJT2G

Overview

NCP139AFCTC06ADJT2G from onsemi is a 1 A very low dropout (VLDO) linear regulator with NMOS pass transistor and separate VBIAS rail, delivering 0.6 V fixed output voltage with ±1% accuracy over temperature. It achieves 50 mV typical dropout at 1 A load and supports stable operation with 10 µF ceramic output capacitance. Designed for space-constrained, noise-sensitive portable applications including smartphone core logic rails.

For engineers reviewing the NCP139AFCTC06ADJT2G datasheet, pinout, applications, or equivalent options, key selection criteria include its dual-rail architecture (VIN/VBIAS), ultra-low bias current (35 µA typ), active discharge capability, and WLCSP6 package compatibility with high-density mobile PCB layouts.

Technical Context

The NCP139AFCTC06ADJT2G implements a dual-input NMOS-based VLDO architecture where VIN supplies the power path and VBIAS (3.0–5.5 V) powers internal control circuitry independently. This separation enables optimized PSRR-85 dB from VBIAS and 70 dB from VIN at 1 kHz-and eliminates VBIAS dependency on output voltage regulation.

It features an integrated thermal shutdown (160°C trip), current limiting (1.5–2.6 A), and logic-level enable input with hysteresis. The device supports monotonic startup and includes active output discharge (NCP139A variant), critical for sequencing in multi-rail systems like application processors.

Key Specifications

Pinout & Package

WLCSP6 (Case 567MV) package: 1.2 mm × 0.8 mm body, 0.4 mm pitch, 6 solder balls, bottom-side coated for enhanced reliability in fine-pitch assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar very-low-dropout linear regulator applications.

Compared with TPS7A1601DRBR and BD750L5FP-E2, the NCP139AFCTC06ADJT2G uniquely delivers 1 A at 50 mV dropout with independent VBIAS control and active discharge-enabling higher efficiency, better noise immunity, and tighter sequencing control in modern mobile SoC power trees.

Availability

NCP139AFCTC06ADJT2G is available at Aetrix Electronics and suitable for smartphone processor core rails, tablet I/O domains, wearable sensor hubs, and ultra-low-power IoT MCU supplies requiring stable component supply with full lifecycle support.

Supply support for NCP139AFCTC06ADJT2G 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 sensor solutions for automotive, industrial, and portable electronics.

The NCP139AFCTC06ADJT2G belongs to onsemi's high-performance VLDO family designed specifically for noise-sensitive, space-constrained mobile applications requiring dual-rail operation and sub-100 mV dropout.

FAQ

What is the exact output voltage tolerance of the NCP139AFCTC06ADJT2G over temperature?

The NCP139AFCTC06ADJT2G provides ±1.0% output voltage accuracy across the full operating junction temperature range of −40°C to +85°C, with tighter ±0.5% accuracy at +25°C. This specification applies under defined test conditions: VBIAS ≥ 3.0 V or (VOUT + 1.6 V), VIN = VOUT(NOM) + 0.3 V, and 1 mA ≤ IOUT ≤ 1.0 A. The NCP139AFCTC06ADJT2G uses a precision bandgap reference and trimmed feedback network to maintain this stability.

Does the NCP139AFCTC06ADJT2G require external resistors for output voltage setting?

No, the NCP139AFCTC06ADJT2G is a fixed-output variant delivering 0.6 V without external resistors. Its marking code "A6" confirms the 0.6 V nominal output. Unlike adjustable versions (e.g., NCP139AFCT06ADJT2G), the NCP139AFCTC06ADJT2G uses internal resistor networks tied to the SNS pin, eliminating component count and layout complexity for dedicated 0.6 V applications.

What is the purpose of the VBIAS pin on the NCP139AFCTC06ADJT2G, and what voltage range must it be supplied with?

The VBIAS pin on the NCP139AFCTC06ADJT2G supplies power exclusively to internal control circuitry-including the reference, error amplifier, and enable logic-decoupling it from the main VIN rail. It must be supplied within 3.0 V to 5.5 V. This architecture enables high PSRR (85 dB) from VBIAS and allows operation even when VIN sags below VOUT + dropout, a key advantage in battery-powered systems where main rails fluctuate.

Can the NCP139AFCTC06ADJT2G be used with ceramic output capacitors smaller than 10 µF?

The NCP139AFCTC06ADJT2G is characterized and guaranteed stable with 10 µF to 22 µF effective ceramic output capacitance. Using capacitors below 10 µF may compromise phase margin and cause instability or oscillation, especially under transient load conditions. The datasheet explicitly recommends maintaining ≥10 µF effective capacitance-accounting for DC bias derating-and direct PCB copper connections to ensure reliable operation of the NCP139AFCTC06ADJT2G.

Is active output discharge enabled by default on the NCP139AFCTC06ADJT2G, and how is it implemented?

Yes, active output discharge is enabled by default on the NCP139AFCTC06ADJT2G, as indicated by the "A" suffix in the part number (NCP139AFCTC06ADJT2G). When the EN pin is driven low, an internal 150 Ω pull-down switch connects VOUT to GND, discharging the output capacitor rapidly. This feature prevents floating voltages during power-down sequencing and is critical for meeting strict reset timing requirements in multi-rail SoC platforms using the NCP139AFCTC06ADJT2G.