onsemi NCP500SQL18T1

Overview

NCP500SQL18T1 from onsemi is a fixed-output, low-noise, low-dropout linear regulator delivering 1.8 V at up to 150 mA. It features ultra-low dropout (170 mV at 150 mA), 50 µV_RMS output noise without bypass capacitor, and fast 20 µs enable turn-on time. Designed for noise-sensitive RF and portable battery-powered systems, it operates from 1.8 V to 6.0 V input and supports ceramic output capacitors as low as 1.0 µF.

For engineers reviewing the NCP500SQL18T1 datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage under load, RMS noise performance in 10 Hz–100 kHz bandwidth, enable logic compatibility down to 1.0 V, thermal shutdown behavior, and DFN 2×2.2 mm package footprint constraints.

Technical Context

The NCP500SQL18T1 uses a PMOS pass transistor architecture enabling ultra-low dropout and eliminating the need for external noise-bypass capacitance. Its internal voltage reference, error amplifier, and protection circuits (current limit and thermal shutdown) are integrated into a single die optimized for stable operation with low-ESR ceramic capacitors.

It achieves high accuracy (±2.5% over −40°C to +85°C) and excellent line/load regulation (≤10 mV and ≤45 mV respectively) while maintaining quiescent current as low as 175 µA at 150 mA load - critical for extended battery life in handheld instrumentation and camera modules.

Key Specifications

Pinout & Package

Package: DFN 2×2.2 mm, 6-pin with exposed thermal pad (Case 506BA). Pin numbering follows top-view orientation per datasheet Figure on page 2.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-1802E/MB and XC6206P182MR-G, the NCP500SQL18T1 delivers superior noise performance, lower dropout, integrated enable functionality, and full protection suite - making it optimal for compact, battery-constrained, and RF-sensitive designs where reliability and signal integrity are prioritized.

Availability

NCP500SQL18T1 is available at Aetrix Electronics and suitable for RF front-end biasing, precision sensor powering, and portable medical instrumentation requiring stable component supply, long-term lifecycle support, and AEC-Q100-aligned manufacturing traceability.

Supply support for NCP500SQL18T1 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 is a global semiconductor manufacturer specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and medical markets.

The NCP500 series was designed specifically for portable battery-powered systems demanding ultra-low noise, fast enable response, and minimal external components - targeting RF, imaging, and instrumentation applications where supply integrity directly impacts system performance.

FAQ

What is the maximum input voltage rating for the NCP500SQL18T1?

The NCP500SQL18T1 has an absolute maximum input voltage of 6.0 V. Operation above this level risks permanent damage. For reliable long-term use, the recommended maximum continuous input is 5.5 V, especially at elevated ambient temperatures where thermal derating applies. The device's dropout voltage increases with load, so maintaining sufficient Vin–Vout margin (≥200 mV) ensures regulation stability across temperature and process variation.

Does the NCP500SQL18T1 require an external bypass capacitor for noise reduction?

No, the NCP500SQL18T1 does not require an external bypass capacitor. Its internal architecture achieves 50 µV_RMS output noise (10 Hz–100 kHz) without any additional capacitor - a key differentiator from conventional LDOs. This simplifies layout, reduces BOM count, and avoids startup delay issues associated with bypass cap charging. External capacitors are still required: ≥1.0 µF ceramic at input and output for stability and transient response.

Can the NCP500SQL18T1 be used with a 1.0 V logic enable signal?

Yes, the NCP500SQL18T1 is explicitly designed for 1.0 V logic compatibility. Its enable input threshold is specified as 0.9 V (typical turn-on) and 0.15 V (typical turn-off), allowing direct connection to 1.0 V GPIO outputs without level-shifting. The enable pin draws only 3.0 nA typical bias current, minimizing loading on low-drive-strength controllers. If unused, Enable must be tied to Vin to ensure default operation.

What is the thermal resistance (R_JA) of the NCP500SQL18T1 in its DFN package?

The NCP500SQL18T1 in the DFN 2×2.2 mm package (Case 506BA) has a junction-to-ambient thermal resistance (R_JA) of 225°C/W under standard JEDEC test conditions. This value assumes a 1-inch² copper pad with two vias. Actual R_JA improves significantly with enhanced PCB copper area and thermal vias beneath the exposed pad - enabling up to 400 mW power dissipation at 25°C ambient if properly implemented.

Is the NCP500SQL18T1 suitable for automotive applications?

The NCP500SQL18T1 is not automotive-qualified. While onsemi offers the pin-compatible NCV500SQL18T1 variant (with NCV prefix) that is AEC-Q100 qualified and PPAP capable, the NCP500SQL18T1 is intended for industrial and consumer applications. It operates across −40°C to +85°C but lacks the extended temperature range (−40°C to +125°C), stress testing, and documentation rigor required for automotive deployment.