onsemi NCP500SN185T1

Overview

NCP500SN185T1 from onsemi is a fixed-output, low-noise, low-dropout linear regulator delivering 1.85 V at up to 150 mA. It features ultra-low dropout (170 mV at 150 mA), 2.5% output voltage accuracy, and operates without an external noise bypass capacitor-ideal for powering RF stages and VCOs in portable battery-powered systems.

For engineers reviewing the NCP500SN185T1 datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage under load, enable logic compatibility (1.0 V–0.15 V thresholds), RMS noise performance (50 µV, 10 Hz–100 kHz), thermal shutdown behavior, and DFN 2×2.2 mm package footprint constraints.

Technical Context

The NCP500SN185T1 uses a PMOS pass transistor architecture enabling ultra-low dropout and fast 20 µs enable turn-on response. Its internal voltage reference, error amplifier, and protection circuits (current limit, thermal shutdown) operate across a 1.8 V–6.0 V input range while maintaining regulation down to 1.85 V output.

No external bypass capacitor is required due to integrated low-noise design; RMS noise remains at 50 µV (10 Hz–100 kHz) with only 1.0 µF ceramic output capacitance. Enable functionality supports direct drive from 1.0 V logic, with threshold voltages of 0.9 V (turn-on) and 0.15 V (turn-off).

Key Specifications

Pinout & Package

The NCP500SN185T1 is housed in a Pb-free DFN 2×2.2 mm package (Case 506BA) with wettable flanks, optimized for space-constrained PCB layouts and automated optical inspection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-1802E/TT, NCP500SN185T1 offers precise 1.85 V output and enable control, while TNIV500S185T1G provides identical performance with automotive compliance-making NCP500SN185T1 optimal for industrial and consumer portable designs requiring flexibility and low-noise integrity.

Availability

NCP500SN185T1 is available at Aetrix Electronics and suitable for portable medical devices, RF front-end modules, battery-powered instrumentation, and SMPS post-regulation applications requiring stable component supply and long-term manufacturability.

Supply support for NCP500SN185T1 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 silicon solutions for automotive, industrial, cloud, medical, and IoT applications.

The NCP500 series was designed specifically for portable battery-powered systems demanding low noise, fast enable response, and ultra-low dropout-enabling longer runtime and cleaner signal integrity in space- and power-constrained designs.

FAQ

What is the maximum input voltage rating for the NCP500SN185T1?

The NCP500SN185T1 has an absolute maximum input voltage of 6.0 V. Exceeding this rating may cause permanent damage. For reliable operation, the input should remain within 1.8 V to 6.0 V, with recommended headroom of ≥170 mV above 1.85 V output to maintain regulation at full 150 mA load. The NCP500SN185T1 datasheet specifies thermal shutdown activation at ~160 °C to protect against overvoltage-induced overheating.

Does the NCP500SN185T1 require an external bypass capacitor for low-noise operation?

No, the NCP500SN185T1 does not require an external bypass capacitor. Its integrated low-noise architecture achieves 50 µV RMS noise (10 Hz–100 kHz) with only a 1.0 µF ceramic output capacitor. This eliminates the need for additional capacitors, simplifies layout, reduces BOM count, and avoids startup delays associated with traditional LDO bypass networks-key advantages confirmed in the NCP500SN185T1 datasheet Figure 19 and Applications Information section.

What is the enable pin behavior and threshold voltage for the NCP500SN185T1?

The NCP500SN185T1 enable pin is active-high with a typical turn-on threshold of 0.9 V and turn-off threshold of 0.15 V. When enabled, quiescent current rises to 175 µA at 150 mA load; when disabled, it drops to 0.01 µA. The pin accepts direct drive from 1.0 V logic families. If unused, the enable pin must be tied to Vin per the NCP500SN185T1 datasheet Pin Function Description to ensure normal operation.

Can the NCP500SN185T1 be used with ceramic output capacitors?

Yes, the NCP500SN185T1 is fully stable with ceramic output capacitors. The datasheet explicitly states it requires only a minimum 1.0 µF ceramic capacitor and does not depend on ESR for stability. Stability testing (Figure 29) confirms robust operation across 1–10 µF ceramic values and ESR down to 10 mΩ. This eliminates reliance on tantalum or aluminum electrolytic capacitors, improving reliability and temperature performance in the NCP500SN185T1 application.

What thermal considerations apply to the NCP500SN185T1 in a DFN 2×2.2 mm package?

The NCP500SN185T1 in its DFN 2×2.2 mm package has a junction-to-ambient thermal resistance (R_JA) of 225 °C/W. At 150 mA load with 2.02 V input (170 mV dropout), power dissipation is ~25.5 mW, resulting in ~5.7 °C junction rise above ambient. To maintain T_J ≤125 °C, ensure adequate copper pour on GND pins (Pins 2 and 6), avoid thermal isolation, and follow onsemi's layout guidelines in the NCP500SN185T1 datasheet Section 12.