onsemi NCP105AMX120TCG

Overview

NCP105AMX120TCG from onsemi is a 150 mA, fixed 1.2 V output low-dropout linear regulator with high PSRR (70 dB at 1 kHz), ultra-low quiescent current (50 µA typ.), and active output discharge. It operates from 1.7 V to 5.5 V input, delivers ±1% output accuracy at room temperature, and is optimized for noise-sensitive, space-constrained battery-powered systems such as smartphone baseband processors and camera sensor power rails.

For engineers reviewing the NCP105AMX120TCG datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage at 150 mA (125 mV typ. @ 2.8 V IN), soft-start slew rate (normal mode, 190 mV/s), thermal shutdown threshold (160°C), and stability with only 1 µF ceramic output capacitor.

Technical Context

The NCP105AMX120TCG implements a PMOS pass transistor architecture with dynamic quiescent current adjustment to minimize IQ across load conditions. Its internal bandgap reference, active discharge circuit (enabled in A/C variants), and thermal shutdown with 20°C hysteresis ensure robust operation under transient overload and thermal stress.

This variant (NCP105A) features normal-slew-rate soft start (190 mV/s), supports 1.2 V fixed output with ±40 mV accuracy over −40°C to +85°C, and maintains stability without ESR requirements on the 1 µF X7R/X5R output capacitor-enabling compact, low-BOM-count designs in portable electronics.

Key Specifications

Pinout & Package

XDFN4 package (1.0 mm × 1.0 mm, 0.65 mm pitch), thermally enhanced with exposed pad tied to GND for efficient heat dissipation in high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A0512PDBVR and MCP1700T-1202E/TT, the NCP105AMX120TCG uniquely combines active discharge, thermal shutdown, and 70 dB PSRR in a 1.0×1.0 mm XDFN4 package-making it optimal for space-constrained, safety-critical portable electronics where rail integrity and sequencing reliability are non-negotiable.

Availability

NCP105AMX120TCG is available at Aetrix Electronics and suitable for smartphone baseband power, camera sensor bias rails, wearable health monitors, Bluetooth LE peripherals, and other battery-powered applications requiring stable component supply with guaranteed long-term availability.

Supply support for NCP105AMX120TCG 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 for automotive, industrial, and portable markets.

The NCP105AMX120TCG belongs to the NCP105 family of high-PSRR, low-IQ LDOs designed specifically for noise-sensitive, battery-operated portable devices requiring precision voltage regulation in minimal footprint.

FAQ

What is the output voltage tolerance of the NCP105AMX120TCG over temperature?

The NCP105AMX120TCG provides ±40 mV output voltage accuracy across the full operating junction temperature range of −40°C to +85°C. This corresponds to ±3.3% tolerance at 1.2 V and is specified independently of line/load regulation-ensuring stable core logic supply even in thermally demanding handheld enclosures where the NCP105AMX120TCG is commonly deployed.

Does the NCP105AMX120TCG support active output discharge, and how does it function?

Yes, the NCP105AMX120TCG (as an "A" variant) includes active output discharge. When the EN pin is pulled below 0.4 V, the device disables regulation and connects the OUT pin to GND via an internal 100 Ω resistor. This rapidly discharges the output capacitor, preventing unintended back-powering or latch-up in multi-rail systems-confirming its suitability for use alongside the NCP105AMX120TCG in sequenced power architectures.

What is the minimum output capacitance required for stability with the NCP105AMX120TCG?

The NCP105AMX120TCG is stable with a minimum 1 µF ceramic (X5R/X7R) output capacitor. The datasheet confirms stability down to 0.47 µF effective capacitance-accounting for DC bias and temperature derating-making 0402-size 1 µF capacitors fully viable. No ESR requirement exists, eliminating the need for tantalum or polymer alternatives when using the NCP105AMX120TCG in high-density portable PCBs.

How does the NCP105AMX120TCG achieve high PSRR despite its small package size?

The NCP105AMX120TCG achieves 70 dB PSRR at 1 kHz through a combination of high-gain error amplifier design, optimized internal compensation, and PMOS pass transistor topology that minimizes gate-drive sensitivity to input ripple. Its performance is validated with 1 µF COUT and no input capacitor-demonstrating inherent immunity to supply noise without external filtering, a key advantage of the NCP105AMX120TCG in compact, cost-sensitive designs.

Is the NCP105AMX120TCG pin-compatible with other variants in the NCP105 family?

Yes, all NCP105 variants-including NCP105AMX120TCG, NCP105AMX280TCG, and NCP105AMX330TCG-share identical XDFN4 (1.0×1.0 mm) pinout and footprint. This allows voltage-option flexibility within the same PCB layout, simplifying BOM management and enabling last-minute design revisions without re-spinning hardware-directly supporting scalable product families using the NCP105AMX120TCG and related parts.