onsemi NCP731ADN500R2G

Overview

NCP731ADN500R2G from onsemi is a fixed-output 5.0 V, 150 mA low-noise CMOS LDO regulator with 8 µV_RMS noise (10 Hz–100 kHz), 290 mV typical dropout at full load, and operation across 2.7 V to 38 V input. It integrates programmable soft-start, thermal shutdown, over-current protection, and stable operation with 1 µF ceramic output capacitors - ideal for powering precision analog circuitry such as op-amps, ADCs, and DACs in industrial instrumentation and battery-powered test equipment.

For engineers reviewing the NCP731ADN500R2G datasheet, pinout, applications, or equivalent options, key selection criteria include its 5.0 V fixed output accuracy (±0.6% at 25°C), ultra-low noise performance, wide VIN range, EN-controlled enable functionality, and Micro-8 EP package compatibility with high thermal efficiency (R_θJB = 19 °C/W).

Technical Context

The NCP731ADN500R2G implements a CMOS-based pass transistor architecture with internal voltage reference (1.2 V), UVLO (2.55 V typ.), and precision error amplifier. Its feedback loop is internally configured for fixed 5.0 V output, eliminating external resistor dividers while retaining ADJ/FF pin functionality for feed-forward capacitor connection to improve PSRR and transient response.

Startup sequencing is governed by dual comparators monitoring both IN voltage (UVLO) and EN pin level (0.9 V typ. threshold), with soft-start timing set by an internal 910 nA current charging an external CSS capacitor. Thermal protection activates at 170 °C with 10 °C hysteresis, and short-circuit current is internally limited to 365 mA typ.

Key Specifications

Pinout & Package

Package: Micro-8 EP (Case 846AT), 3 mm × 3 mm, exposed pad (EPAD) thermally connected to GND. Pin pitch: 0.5 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV7555PDBVR and MCP1703T-5002E/MB, the NCP731ADN500R2G uniquely combines 38 V input tolerance, 8 µV_RMS noise, integrated thermal/over-current protection, and soft-start programmability - making it the only option qualified for high-reliability industrial analog power domains.

Availability

NCP731ADN500R2G is available at Aetrix Electronics and suitable for industrial instrumentation, battery-powered test equipment, and precision analog signal chains requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for NCP731ADN500R2G 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 is a global semiconductor supplier delivering energy-efficient silicon solutions for automotive, industrial, cloud, medical, and IoT applications.

The NCP731ADN500R2G belongs to onsemi's precision low-noise LDO family, engineered specifically for powering high-resolution analog circuits where rail cleanliness, wide input range, and robust protection are mandatory.

FAQ

What is the output voltage tolerance of the NCP731ADN500R2G over temperature?

The NCP731ADN500R2G maintains ±1.0% output voltage accuracy from −40°C to +85°C and ±1.5% from −40°C to +125°C. This specification applies under standard test conditions (VIN = VOUT-NOM + 1 V, IOUT = 0.1–150 mA) and ensures reliable operation in industrial environments where ambient temperatures fluctuate widely. The 5.0 V output remains tightly regulated without external trimming components.

Can the NCP731ADN500R2G operate with a 3.3 V input supply?

No - the NCP731ADN500R2G requires a minimum input voltage of 2.7 V, but its dropout voltage is 230 mV typ. at 150 mA. To deliver regulated 5.0 V output, VIN must exceed 5.23 V. At 3.3 V input, the device enters dropout and cannot sustain 5.0 V output. It is designed for applications with VIN ≥ 5.5 V, such as 12 V or 24 V industrial rails stepped down via upstream DC-DC conversion.

Does the NCP731ADN500R2G require an external feed-forward capacitor (CFF)?

The NCP731ADN500R2G does not require CFF for basic operation - it is optional. Connecting a 10 nF capacitor between the ADJ/FF pin and OUT improves PSRR (especially at 10–100 kHz) and reduces output noise, but increases startup time. If fast turn-on or minimal component count is prioritized, CFF may be omitted without compromising stability or regulation.

How is thermal performance affected by the exposed pad (EPAD) connection on the NCP731ADN500R2G?

The EPAD on the NCP731ADN500R2G must be soldered to a dedicated GND copper pour to achieve the specified R_θJB = 19 °C/W. Without proper EPAD grounding, junction-to-board thermal resistance degrades significantly, increasing die temperature by up to 45°C at 150 mA load. This can trigger thermal shutdown prematurely or reduce long-term reliability. A minimum 2×2 mm GND pad with ≥4 thermal vias is recommended.

Is the NCP731ADN500R2G compatible with ceramic output capacitors below 1 µF?

No - the NCP731ADN500R2G is characterized and guaranteed stable only with output capacitance from 1 µF to 1000 µF. Using capacitors below 1 µF risks instability, oscillation, or degraded transient response. The datasheet explicitly specifies "stable with small 1 µF ceramic capacitors", and design validation assumes ≥1 µF effective capacitance (accounting for DC bias and temperature derating).