onsemi NCP500SQL50T1G

Overview

NCP500SQL50T1G from onsemi is a fixed-output, low-noise, low-dropout linear regulator (LDO) delivering 150 mA with 5.0 V output, ultra-low 170 mV dropout at full load, 20 µs enable turn-on time, and 50 µV_RMS noise (10 Hz–100 kHz) without bypass capacitor - ideal for powering RF stages and VCOs in portable battery-powered systems.

For engineers reviewing the NCP500SQL50T1G datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage at 150 mA, enable logic compatibility down to 1.0 V, RMS noise performance, thermal shutdown behavior, and DFN 2×2.2 mm package footprint constraints.

Technical Context

The NCP500SQL50T1G employs a PMOS pass transistor architecture enabling ultra-low dropout and fast transient response. Its internal voltage reference, error amplifier, and protection circuits (current limit and thermal shutdown) operate independently of external components, supporting stable regulation with only 1.0 µF input and output ceramic capacitors.

Enable functionality is implemented via a high-impedance input (I_IB ≤ 100 nA) with asymmetric thresholds (V_TH(HI) = 0.9 V, V_TH(LO) = 0.15 V), allowing direct interfacing with 1.0 V logic while ensuring robust noise immunity during power sequencing.

Key Specifications

Pinout & Package

Package: DFN 2×2.2 mm, 6-pin, exposed thermal pad (Case 506BA). Pin 6 is GND and shares thermal mass with the die paddle.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-5002E/MB and TLC7705IPW, the NCP500SQL50T1G delivers superior dropout performance (170 mV vs. ≥250 mV) and integrated enable control - critical for battery-powered systems requiring dynamic power gating and tight input voltage margins.

Availability

NCP500SQL50T1G is available at Aetrix Electronics and suitable for RF front-end biasing, VCO supply regulation, and SMPS post-regulation requiring stable component supply, low-noise operation, and compact DFN packaging.

Supply support for NCP500SQL50T1G 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 supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The NCP500 series is designed specifically for portable battery-powered systems demanding ultra-low noise, fast enable response, and minimal external components - targeting RF, imaging, and precision analog subsystems.

FAQ

What is the maximum input voltage rating for the NCP500SQL50T1G?

The NCP500SQL50T1G has an absolute maximum input voltage rating of 6.0 V. Operation above this level risks permanent damage. For inputs exceeding 6.0 V, an external pre-regulator (e.g., resistive divider or Zener clamp) must be used - though thermal limits and efficiency trade-offs apply. The device is optimized for 1.8–6.0 V operation, with best dropout performance achieved near its 5.0 V output.

Does the NCP500SQL50T1G require an external bypass capacitor to achieve its specified 50 µV_RMS noise?

No, the NCP500SQL50T1G achieves its 50 µV_RMS noise (10 Hz–100 kHz) without any external bypass capacitor due to its proprietary low-noise internal architecture. Adding a bypass capacitor may degrade startup time and is unnecessary for noise performance - simplifying layout and reducing bill-of-materials cost. This distinguishes it from conventional LDOs that rely on external capacitors for noise filtering.

What is the thermal shutdown threshold and recovery behavior of the NCP500SQL50T1G?

The NCP500SQL50T1G incorporates internal thermal shutdown that activates at approximately 160°C junction temperature. Once triggered, the regulator disables output until junction temperature falls below the hysteresis threshold (~140°C). Recovery is automatic and does not require cycling enable or input power. Thermal resistance (R_JA) is 225°C/W for the DFN 2×2.2 mm package, meaning 400 mW max power dissipation at 25°C ambient before reaching 125°C T_J(max).

Can the NCP500SQL50T1G be used with ceramic output capacitors smaller than 1.0 µF?

No - the NCP500SQL50T1G requires a minimum 1.0 µF ceramic output capacitor for guaranteed stability across all operating conditions. Using smaller values risks oscillation or degraded transient response. The datasheet explicitly specifies 1.0 µF as the minimum, and stability testing (Figure 29) confirms instability below this value, especially with ESR < 10 mΩ. Larger values (e.g., 2.2–10 µF) improve load transient suppression and noise rejection.

How does the enable pin of the NCP500SQL50T1G behave when left unconnected?

The enable pin of the NCP500SQL50T1G must not be left floating. If unused, it must be connected directly to V_IN to ensure reliable operation. An unconnected enable pin introduces undefined logic states, potentially causing erratic output behavior or failure to power up. The input bias current is extremely low (≤100 nA), so connecting to V_IN imposes negligible load and guarantees the device remains enabled at all times.