onsemi MC78LC28NTRG

Overview

MC78LC28NTRG from onsemi is a fixed-output, micropower low-dropout linear voltage regulator delivering 2.8 V at up to 80 mA with 1.1 µA typical quiescent current and 30 mV dropout (at 1 mA). It uses a PMOS pass transistor, operates from 2.8 V to 12 V input, and maintains ±2.5% output accuracy across −40°C to +85°C for battery-powered instrumentation.

For engineers reviewing the MC78LC28NTRG datasheet, pinout, applications, or equivalent options, key selection criteria include ultra-low IQ for multi-year battery life, ceramic capacitor compatibility (≥0.1 µF), SOT-23-5 footprint constraints, and thermal derating in compact portable enclosures.

Technical Context

The MC78LC28NTRG implements a PMOS-based LDO architecture with internal voltage reference, error amplifier, and feedback resistors trimmed for 2.8 V nominal output. Its ultra-low quiescent current stems from bias circuit optimization rather than sleep modes, enabling continuous regulation without wake-up latency.

It achieves stable operation with 0.1 µF ceramic output capacitors due to inherent phase margin design - no ESR requirements - and exhibits 40 mV load regulation (1–10 mA) and 0.05%/V line regulation, making it suitable for dynamically varying supply rails in handheld devices.

Key Specifications

Pinout & Package

MC78LC28NTRG is housed in a Pb-free Thin SOT-23-5 (Case 483) surface-mount package measuring 3.0 mm × 1.5 mm × 0.95 mm, with exposed thermal pad connected to Pin 2 (Vin).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-2802E/TT and TPS78028DRVR, the MC78LC28NTRG offers optimal balance of ultra-low IQ, minimal footprint (SOT-23-5), and zero-configuration operation - no enable pin or external components required - making it ideal for cost-sensitive, space-constrained, long-life portable designs.

Availability

MC78LC28NTRG is available at Aetrix Electronics and suitable for portable medical sensors, wireless remotes, handheld test meters, and smart home motion detectors requiring stable component supply with guaranteed long-term sourcing.

Supply support for MC78LC28NTRG 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 MC78LC00 series was designed specifically for micropower, battery-critical applications such as handheld instruments and portable communications equipment where ultra-low IQ and small footprint are essential.

FAQ

What is the maximum output current capability of the MC78LC28NTRG?

The MC78LC28NTRG delivers up to 80 mA continuous output current when Vin ≥ 5.0 V, as specified in the Electrical Characteristics table. At lower input voltages (e.g., Vin = 3.2 V), output current is limited by thermal dissipation - the 280 °C/W junction-to-ambient rating requires careful PCB copper area design to sustain >50 mA without exceeding 125°C junction temperature.

Does the MC78LC28NTRG require an external output capacitor, and what type is recommended?

Yes, the MC78LC28NTRG requires a minimum 0.1 µF ceramic output capacitor placed within 2 mm of the Vout and GND pins. The device is stable with ceramic capacitors ranging from 0.1 µF to 10 µF and does not require specific ESR - unlike many older LDOs, it imposes no minimum ESR constraint, simplifying design and reducing BOM cost.

Can the MC78LC28NTRG be used with a single-cell lithium battery?

Yes, the MC78LC28NTRG is explicitly suited for single-cell Li-ion (3.0–4.2 V) and Li-polymer batteries. Its 2.8 V output and 30 mV dropout at 1 mA allow regulation down to Vin = 2.83 V, capturing nearly the full discharge curve - including the flat 3.6–3.0 V region - before cutoff, maximizing usable battery energy.

What is the thermal performance limitation of the MC78LC28NTRG in SOT-23-5 package?

In the Thin SOT-23-5 (NTR) package, the MC78LC28NTRG has a junction-to-ambient thermal resistance of 280 °C/W. At ambient 25°C and 80 mA load with 5.0 V input, power dissipation is (5.0 − 2.8) V × 0.08 A = 176 mW, resulting in ~49°C junction rise - well within the 125°C limit. However, at 85°C ambient, max continuous current drops to ~50 mA to maintain TJ ≤ 125°C.

Is the MC78LC28NTRG pin-compatible with other devices in the MC78LC00 series?

Yes, all MC78LC00 series variants - including MC78LC18NTRG, MC78LC25NTRG, MC78LC30NTRG, and MC78LC33NTRG - share identical SOT-23-5 pinout (GND, Vin, Vout, N/C, N/C) and package dimensions. This allows direct substitution across output voltages without PCB layout changes, provided input voltage and load requirements remain compatible.