onsemi NCP4632DDT28T5G

Overview

NCP4632DDT28T5G from onsemi is a 3 A, low-dropout linear voltage regulator with fixed 2.8 V output, reverse current protection, and active discharge functionality. It operates from 1.6 V to 5.25 V input, delivers ±1% output accuracy, maintains 510 mV typical dropout at 3 A load, and draws only 350 µA quiescent current-ideal for battery-powered portable equipment requiring stable low-voltage rail generation.

For engineers reviewing the NCP4632DDT28T5G datasheet, pinout, applications, or equivalent options, key selection criteria include its DPAK-5 package thermal performance (R_JA = 53 °C/W), 2.8 V fixed output with 0.1 V step granularity, active discharge capability for fast V_OUT ramp-down, and compatibility with ceramic output capacitors down to 10 µF.

Technical Context

The NCP4632DDT28T5G integrates a CMOS pass element with reverse current detection logic that disables the output when V_OUT exceeds VIN by >30 mV, limiting reverse leakage to <10 µA. Its internal reference is trimmed to ±1% over −40°C to +85°C, and line regulation is specified at 0.15%/V typical.

It features soft-start via internal current limiting during turn-on, thermal shutdown protection, and current fold-back limiting (220 mA typical) under short-circuit conditions. The CE pin enables logic-level control with 1.0 V high-threshold and 0.4 V low-threshold, and the D-version includes an integrated N-channel discharge transistor tied between V_OUT and GND.

Key Specifications

Pinout & Package

DPAK-5 (TO-252-5) package with exposed thermal pad internally connected to Pin 3 (GND). Standard 4-layer PCB layout requires ≥600 mm² copper pour under the tab for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A2028PDQNR and MCP1826-2802E/DB, the NCP4632DDT28T5G uniquely combines reverse current blocking, active discharge, and 350 µA operating IQ in a single DPAK-5 package - making it optimal for space-constrained, battery-operated systems demanding both efficiency and fault resilience.

Availability

NCP4632DDT28T5G is available at Aetrix Electronics and suitable for smartphone power management, wearable sensor hubs, industrial handheld terminals, and automotive infotainment displays requiring stable component supply with guaranteed long-term availability.

Supply support for NCP4632DDT28T5G 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, serving automotive, industrial, cloud, and medical markets with power, analog, sensor, and connectivity solutions.

The NCP4632DDT28T5G belongs to onsemi's high-current, low-dropout LDO family designed specifically for battery-powered portable electronics needing precision voltage regulation, ultra-low IQ, and robust fault protection in compact surface-mount packages.

FAQ

What is the maximum input voltage rating for the NCP4632DDT28T5G?

The absolute maximum input voltage for the NCP4632DDT28T5G is 6.0 V. However, per the datasheet, sustained operation above 5.25 V is limited to ≤500 hours total lifetime, even if junction temperature remains within limits. For reliable long-term use, the recommended maximum operating input voltage is 5.25 V - consistent with its specified operating input range of 1.6 V to 5.25 V.

Does the NCP4632DDT28T5G require external compensation components?

No, the NCP4632DDT28T5G is internally compensated and stable with 10 µF ceramic output capacitors - no external resistors or capacitors are needed for loop stability. The datasheet explicitly confirms stability with ceramic capacitors and provides layout guidance (short traces, close placement) rather than compensation networks, distinguishing it from older LDO architectures requiring external ESR tuning.

How does the active discharge function operate in the NCP4632DDT28T5G?

When the CE pin is driven low, the NCP4632DDT28T5G disables its main pass transistor and simultaneously turns on an internal N-channel MOSFET between VOUT and GND. This provides a low-resistance path (R_LOW = 30 Ω typical) to discharge the output capacitor rapidly - reducing VOUT to near-zero in under 2 ms for a 100 µF load, enabling fast system power-state transitions without residual voltage hold-up.

Can the NCP4632DDT28T5G be used with input voltages below 2.8 V?

Yes - the NCP4632DDT28T5G can operate with input voltages as low as 1.6 V, but output regulation is only maintained while VIN ≥ VOUT + V_DO. At 3 A load, V_DO is 510 mV typical, so minimum functional VIN is ~3.31 V. Below that, the device enters dropout mode and VOUT tracks VIN minus V_DO, remaining useful for undervoltage detection or pre-regulation stages despite losing regulation.

What thermal performance can be expected from the NCP4632DDT28T5G on a standard PCB?

On a JEDEC-standard 4-layer FR4 board (76.2 mm × 114.3 mm), the NCP4632DDT28T5G has a junction-to-air thermal resistance (R_JA) of 53 °C/W. At 3 A load with 2.8 V output and 3.3 V input (0.5 V dropout), power dissipation is 1.5 W - resulting in ~80°C junction rise above ambient. With adequate copper pour under the thermal tab, it sustains full load continuously at +25°C ambient without thermal shutdown.