onsemi NCP145AMX100TCG

Overview

NCP145AMX100TCG from onsemi is a 500 mA very low dropout (VLDO) linear voltage regulator with NMOS pass transistor and separate bias rail (VBIAS), delivering stable 1.00 V output for noise-sensitive, space-constrained portable electronics. It features ±1.5% output accuracy over temperature, 140 mV typical dropout at 500 mA, and ultra-low 80 µA bias supply current - enabling high-efficiency operation in battery-powered systems such as smartphone core logic rails.

For engineers reviewing the NCP145AMX100TCG datasheet, pinout, applications, or equivalent options, key selection criteria include dual-rail input architecture (VIN/VBIAS), active output discharge capability, XDFN4 1.2 mm × 1.2 mm package constraints, and compatibility with 2.2 µF ceramic output capacitors.

Technical Context

The NCP145AMX100TCG uses an NMOS pass transistor powered by a dedicated VBIAS rail (2.4–5.5 V), decoupling control circuitry from VIN to enable stable regulation even when VIN drops near VOUT. This architecture achieves ultra-low dropout while maintaining PSRR of 80 dB from VBIAS and 70 dB from VIN at 1 kHz.

It integrates undervoltage lockout (UVLO) on the BIAS pin with 1.6 V threshold and 0.2 V hysteresis, logic-level EN input with 0.9 V turn-on threshold, and thermal shutdown at 160°C. The 'A' option variant includes active output discharge via a 150 Ω internal pull-down when disabled.

Key Specifications

Pinout & Package

XDFN4 package: 1.2 mm × 1.2 mm × 0.4 mm, 5-pin, exposed thermal pad (Case 711BC). Optimized for high-density portable PCBs with minimal thermal resistance (R_JA = 170°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A0510PDBVR and MCP1826T-1002E/DB, the NCP145AMX100TCG uniquely supports dual-rail operation and active output discharge in a 1.2 mm × 1.2 mm package - essential for battery-powered devices needing maximum efficiency, precise sequencing, and noise isolation.

Availability

NCP145AMX100TCG is available at Aetrix Electronics and suitable for smartphone core logic rails, tablet I/O domain power, digital camera sensor bias, STB memory interface regulation, and other applications requiring stable component supply with guaranteed long-term manufacturability.

Supply support for NCP145AMX100TCG 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 sensing technologies.

The NCP145AMX100TCG belongs to onsemi's VLDO regulator product line, designed specifically for space-constrained, battery-operated portable devices demanding ultra-low dropout, low IQ, and high PSRR in dual-rail configurations.

FAQ

What is the minimum input voltage required for NCP145AMX100TCG to regulate 1.00 V at 500 mA?

The NCP145AMX100TCG requires VIN ≥ VOUT + V_DO, where V_DO is 140 mV typical at 500 mA. Thus, minimum functional VIN is 1.14 V. However, stable operation also requires VBIAS ≥ 2.4 V - typically supplied from a higher-voltage system rail like 2.8 V or 3.3 V. The device will not regulate if either VIN or VBIAS falls below their respective minimums.

Does NCP145AMX100TCG support active output discharge, and how does it function?

Yes, the NCP145AMX100TCG includes active output discharge. When the EN pin is driven low (<0.4 V), an internal 150 Ω pull-down resistor connects OUT to GND, discharging the output capacitor rapidly. This feature is confirmed in the datasheet block diagram (Figure 2 footnote) and electrical characteristics table for 'A' option devices - ensuring safe, controlled power-down sequencing in systems with multiple voltage domains.

Can NCP145AMX100TCG operate with only VIN connected, leaving BIAS unconnected?

No. The NCP145AMX100TCG requires both VIN and VBIAS to be within specification for regulation. The BIAS pin powers all internal control circuitry including the reference, error amplifier, and gate driver. If VBIAS is unconnected or below 2.4 V, the internal UVLO disables the regulator regardless of VIN or EN state - as specified in the Absolute Maximum Ratings and Pin Function Description tables.

What ceramic capacitor value is required for stable operation of NCP145AMX100TCG?

The NCP145AMX100TCG is stable with a minimum effective output capacitance of 2.2 µF using X5R/X7R ceramic capacitors. The datasheet explicitly states stability across 2.2 µF to 10 µF and confirms operation with 2.2 µF in Figures 12 and 14. Lower values risk instability; larger values improve transient response but are not required for basic functionality.

Is NCP145AMX100TCG RoHS compliant and lead-free?

Yes, the NCP145AMX100TCG is RoHS compliant and Pb-free, as stated in the Features section and Ordering Information table. The "G" suffix in the part number denotes lead-free packaging, and the device meets halogen-free/BFR-free requirements per the datasheet revision notes and environmental compliance statements on page 1.