onsemi NCP4683DSQ18T1G

Overview

NCP4683DSQ18T1G from onsemi is a 300 mA CMOS low-dropout linear regulator with fixed 1.8 V output, ±1.0% accuracy (VOUT > 2.0 V), 0.25 V dropout at 300 mA/2.8 V, and 70 dB PSRR at 1 kHz. It features chip enable (active-high), current fold-back protection, and stable operation with ≥1.0 µF ceramic output capacitors. It powers core logic in compact battery-powered communication equipment.

For engineers reviewing the NCP4683DSQ18T1G datasheet, pinout, applications, or equivalent options, key selection criteria include its SC-70 package footprint, auto-discharge capability (D-version), 50 µA quiescent current, and thermal performance in high-density portable designs.

Technical Context

The NCP4683DSQ18T1G implements a CMOS-based LDO architecture with internal N-channel pass transistor and precision bandgap reference. Its active-high CE pin controls full rail shutdown with sub-1.0 µA standby current, and the D-version integrates an output discharge FET to rapidly deplete VOUT capacitance during disable.

Designed for low-noise, low-power applications, it delivers 65 µV_RMS output noise (10 Hz–100 kHz) and maintains stability across −40°C to +85°C ambient with minimal external components-only input and output ceramic capacitors required.

Key Specifications

Pinout & Package

Package: SC-70 (Case 419A-02), 5-pin, Pb-free, 1.80 × 1.15 mm footprint, 0.65 mm pitch. Exposed pad not present; thermal path relies on PCB copper.

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 NCP4683DSQ18T1G uniquely combines 300 mA capability, active-high CE, and integrated auto-discharge in SC-70-enabling compact, low-power, and fast-shutdown systems without added discrete components.

Availability

NCP4683DSQ18T1G is available at Aetrix Electronics and suitable for battery-powered equipment, networking hardware, and industrial camera modules requiring stable component supply and long-term production continuity.

Supply support for NCP4683DSQ18T1G 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 delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and edge applications.

The NCP4683 series belongs to onsemi's precision low-dropout regulator product line, engineered for space-constrained, low-power portable electronics requiring high accuracy, low noise, and fast transient response.

FAQ

What is the maximum input voltage rating for the NCP4683DSQ18T1G?

The NCP4683DSQ18T1G has an absolute maximum input voltage of 6.0 V. Operation beyond this limit risks permanent damage. For reliable long-term use, the recommended operating input range is 1.40 V to 5.25 V, as specified in the Electrical Characteristics table. This range ensures optimal dropout performance and thermal safety under all load and temperature conditions.

Does the NCP4683DSQ18T1G require an external resistor network to set output voltage?

No, the NCP4683DSQ18T1G is a fixed-output regulator with factory-trimmed 1.8 V output. It does not support adjustable output via external resistors. The "DSQ" prefix and "18" in the part number explicitly denote the 1.8 V fixed version in SC-70 package with auto-discharge functionality.

How does the auto-discharge feature operate in the NCP4683DSQ18T1G?

When the CE pin is driven low, the NCP4683DSQ18T1G activates an internal N-channel FET between VOUT and GND. This provides a low-impedance discharge path, rapidly depleting output capacitance-typically within <1 ms for 1 µF. This prevents back-powering of downstream circuitry and ensures predictable power sequencing in multi-rail systems.

Can the NCP4683DSQ18T1G be used with tantalum output capacitors?

No-tantalum capacitors are not recommended for the NCP4683DSQ18T1G. Its control loop is optimized for ceramic capacitors ≥1.0 µF with low ESR. Tantalum capacitors typically exhibit higher ESR, which can cause instability and oscillation. The datasheet explicitly warns that using high-ESR capacitors like tantalum may result in loop oscillation and unreliable regulation.

What is the thermal resistance (R_JA) of the NCP4683DSQ18T1G in its SC-70 package?

The NCP4683DSQ18T1G in SC-70 package has a junction-to-air thermal resistance (R_JA) of 263°C/W, as specified in the Thermal Characteristics table. This value assumes standard JEDEC test board conditions (2s2p copper). Actual R_JA in end-application PCBs depends heavily on copper area, layer count, and airflow; adding thermal vias under the package improves heat dissipation significantly.