onsemi NCP4682DMU18TCG

Overview

NCP4682DMU18TCG from onsemi is a 150 mA ultra-low-quiescent-current CMOS low-dropout linear regulator with 1.8 V fixed output, ±0.8% output voltage accuracy, 0.28 V dropout (at 150 mA), and integrated chip enable (CE) for power gating-designed for battery-powered portable electronics requiring stable low-noise supply under light-load conditions.

For engineers reviewing the NCP4682DMU18TCG datasheet, pinout, applications, or equivalent options, key selection criteria include its 1.0 µA quiescent current, auto-discharge function during shutdown, UDFN4 1.0 × 1.0 mm package, and compatibility with 0.1 µF ceramic output capacitors without external compensation.

Technical Context

The NCP4682DMU18TCG implements a PMOS pass transistor architecture enabling ultra-low IQ and fast load transient response. Its CE input operates with active-high logic (V_CEH = 1.5 V min), and internal pull-down ensures default disable state when unconnected.

It integrates fold-back current limiting (40 mA short-circuit current) and an internal output discharge transistor (NCP4682D variant only), which actively pulls VOUT to GND during disable-critical for sequencing-sensitive systems and reducing residual output voltage hold-up time.

Key Specifications

Pinout & Package

Package: UDFN4 1.0 × 1.0 mm, 0.65 mm pitch, exposed thermal pad (GND-connected). Pin 1 marked by microdot; tab is internally connected to GND and should be soldered to PCB ground plane for optimal thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-1802E/TT and XC6206P182MR-G, the NCP4682DMU18TCG uniquely combines ultra-low IQ, integrated CE, and auto-discharge in a 1.0 × 1.0 mm UDFN - delivering superior power sequencing control and smallest footprint for space-constrained battery systems.

Availability

NCP4682DMU18TCG is available at Aetrix Electronics and suitable for wearable health sensors, IoT edge nodes, smart home motion detectors, and portable medical diagnostic devices requiring stable component supply with guaranteed long-term manufacturability.

Supply support for NCP4682DMU18TCG 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, delivering high-performance silicon solutions for automotive, industrial, cloud, and intelligent power systems.

The NCP4682DMU18TCG belongs to onsemi's ultra-low-IQ LDO family, engineered specifically for battery-powered portable electronics where extended runtime, precise voltage regulation, and robust power sequencing are mandatory design requirements.

FAQ

What is the maximum input voltage rating for the NCP4682DMU18TCG?

The absolute maximum input voltage for the NCP4682DMU18TCG is 6.0 V per the Absolute Maximum Ratings table. However, the recommended operating input voltage range is 1.70 V to 5.25 V. Operation above 5.25 V is not advised for continuous use, as the datasheet specifies that exceeding 5.25 V requires strict time-limited operation (≤500 hours total) at ≤5.50 V to ensure reliability. The NCP4682DMU18TCG is designed for low-voltage battery and intermediate rail applications-not high-input industrial supplies.

Does the NCP4682DMU18TCG require an external resistor divider for output voltage setting?

No, the NCP4682DMU18TCG does not require an external resistor divider. It is a fixed-output LDO with factory-trimmed 1.8 V regulation. The device uses internal precision feedback resistors and bandgap reference to achieve ±0.8% output voltage accuracy across temperature and load. External resistors are neither supported nor necessary-this simplifies design, reduces component count, and improves long-term stability compared to adjustable LDOs.

How does the auto-discharge function operate in the NCP4682DMU18TCG?

The NCP4682DMU18TCG (D-series variant) includes an internal N-channel MOSFET between VOUT and GND that activates automatically when the CE pin is driven low. This transistor rapidly discharges the output capacitor, reducing VOUT to <100 mV within tens of microseconds. This behavior prevents residual voltage from powering downstream circuitry unintentionally and supports deterministic power-down sequences required in medical and safety-critical applications. The NCP4682DMU18TCG implements this feature without external components.

Can the NCP4682DMU18TCG be used with a 0.1 µF ceramic output capacitor?

Yes, the NCP4682DMU18TCG is explicitly characterized and guaranteed stable with a minimum 0.1 µF ceramic output capacitor-no ESR requirements or additional series resistance needed. This is confirmed in both the Features list ("Stable with Ceramic Capacitors: 0.1 µF or more") and the Application Information section. Using larger values (e.g., 1 µF) further improves load transient response, but 0.1 µF is sufficient for basic regulation stability in most portable designs using the NCP4682DMU18TCG.

What is the thermal performance of the NCP4682DMU18TCG in its UDFN4 package?

The NCP4682DMU18TCG in the UDFN4 1.0 × 1.0 mm package has a junction-to-air thermal resistance (R_JA) of 250 °C/W, as specified in the Thermal Characteristics table. At full 150 mA load with 2.08 V input (0.28 V dropout), power dissipation is 42 mW, resulting in a worst-case junction temperature rise of 10.5 °C above ambient-well within the −40°C to +150°C operating range. Effective thermal relief requires connecting the exposed thermal pad to a solid PCB ground plane; omitting this increases R_JA significantly and risks thermal shutdown under sustained load.