onsemi NCP502SQ28T2G

Overview

NCP502SQ28T2G from onsemi is a fixed-output, low-quiescent-current CMOS linear voltage regulator delivering 2.8 V at up to 80 mA with 40 µA typical quiescent current and ±2.0% output voltage accuracy over −40 °C to +85 °C. It uses a PMOS pass transistor for ultra-low dropout performance and is designed for battery-powered portable electronics requiring stable, low-power supply regulation.

For engineers reviewing the NCP502SQ28T2G datasheet, pinout, applications, or equivalent options, key selection criteria include its SC70-5 package footprint, 2.8 V fixed output, 850 mV max dropout at 80 mA (TA = −40 °C to +85 °C), enable threshold compatibility (1.3 V high / 0.3 V low), and ceramic-capacitor stability without ESR requirements.

Technical Context

The NCP502SQ28T2G implements a PMOS-based LDO architecture with internal voltage reference, error amplifier, thermal shutdown, and current-limit protection. Its enable input supports logic-level control with defined turn-on/turn-off thresholds, and it operates without minimum load or specific ESR output capacitors.

Designed for handheld and portable applications, it achieves stable regulation using only 1.0 µF ceramic input/output capacitors and maintains 2.0% output accuracy across line (Vin = Vout + 1.0 V to 12 V), load (1–80 mA), and temperature (−40 °C to +85 °C) variations.

Key Specifications

Pinout & Package

Package: SC70-5 (Case 419A), 1.25 mm × 2.1 mm × 0.95 mm, Pb-free, micro-miniature surface-mount.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-2802E/TT, NCP502SQ28T2G provides enable control and integrated protection at higher I_Q; compared with TNIV502SQ28T2G, it offers identical performance at lower cost and shorter lead time for non-automotive industrial use.

Availability

NCP502SQ28T2G is available at Aetrix Electronics and suitable for wearable health monitors, Bluetooth Low Energy modules, industrial handheld scanners, smart home sensor nodes, and other portable electronics requiring stable component supply with low quiescent current and small-footprint packaging.

Supply support for NCP502SQ28T2G 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.

The NCP502 series belongs to onsemi's precision low-I_Q LDO portfolio, engineered specifically for battery-powered portable equipment where extended runtime, small size, and ceramic-capacitor simplicity are critical design constraints.

FAQ

What is the maximum input voltage rating for the NCP502SQ28T2G?

The NCP502SQ28T2G has an absolute maximum input voltage of 12 V, as specified in the Maximum Ratings table. Operation above this level risks permanent damage. For reliable long-term use, input voltage should remain within 2.8 V + dropout (≤3.65 V at 80 mA) up to 12 V, with thermal derating applied at higher loads or ambient temperatures.

Does the NCP502SQ28T2G require an external pull-up resistor on the Enable pin?

No, the NCP502SQ28T2G does not require an external pull-up on the Enable pin. If enable functionality is unused, the datasheet explicitly states that the Enable pin should be connected directly to Vin to ensure continuous operation. Adding a pull-up resistor introduces unnecessary leakage and board complexity.

Can the NCP502SQ28T2G operate with a 1.0 µF ceramic output capacitor only?

Yes, the NCP502SQ28T2G is fully stable with a single 1.0 µF X5R or X7R ceramic capacitor on the output, as confirmed in the Applications Information section. Unlike many older LDOs, it imposes no minimum ESR requirement, eliminating the need for tantalum or aluminum electrolytic capacitors.

What is the dropout voltage of the NCP502SQ28T2G at 50 mA and 25 °C?

While the datasheet specifies 850 mV maximum dropout at 80 mA and full temperature range, Figure 10 shows dropout voltage versus temperature at multiple loads. At 50 mA and 25 °C, the dropout is approximately 650 mV - derived from interpolation of the 40 mA and 80 mA curves in the graph, consistent with the PMOS architecture's linear load dependence.

Is the NCP502SQ28T2G pin-compatible with other variants in the NCP502 family?

Yes, all SC70-5 packaged NCP502 variants - including NCP502SQ28T2G, NCP502SQ29T2G, and NCP502SQ30T2G - share identical pinout, package dimensions, and thermal characteristics. Only the output voltage and top-marking code differ; no PCB redesign is needed when substituting between these fixed-voltage versions.