onsemi NCP1400ASN25T1G

Overview

NCP1400ASN25T1G from onsemi is a micropower fixed-frequency PWM step-up DC-DC switching regulator designed for ultra-low-voltage battery-powered portable systems. It starts up at 0.8 V, operates down to 0.2 V, delivers up to 100 mA output current at 2.5 V regulated output, and integrates oscillator, PWM controller, error amplifier, soft-start, and power MOSFET in TSOP-5 package - enabling compact boost converters for handheld instrumentation and white LED torch lighting.

For engineers reviewing the NCP1400ASN25T1G datasheet, pinout, applications, or equivalent options, key selection criteria include startup voltage margin below 1.0 V, discontinuous-mode stability with minimal external components (inductor, diode, two capacitors), CE-controlled shutdown for <1.5 µA off-state current, and ±2.5% output voltage accuracy over temperature.

Technical Context

The NCP1400ASN25T1G implements a voltage-mode PWM architecture with an internal 180 kHz oscillator (±20% tolerance, 0.11%/°C tempco) and phase-compensated error amplifier optimized for stable operation in discontinuous conduction mode. Its integrated current-limit protection monitors LX voltage to enforce ~350 mA peak switch current, preventing inductor saturation and MOSFET overstress.

Startup and hold behavior is defined by dedicated thresholds: minimum startup voltage is 0.8 V (typ), decreasing −1.6 mV/°C over −40°C to +85°C ambient; minimum hold voltage is 0.3 V (min). The CE pin features an internal 150 nA pull-up to OUT, allowing floating-enable operation while requiring strict 0–0.3 V (disable) or ≥0.9 V (enable) logic levels to avoid undefined states.

Key Specifications

Pinout & Package

Package: TSOP-5 (Case 483), 3.0 mm × 1.5 mm × 1.0 mm profile, lead pitch 0.95 mm, Pb-free matte tin finish.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-up regulator applications.

Compared with TPS61022DRVR and MAX17222ELT+T, the NCP1400ASN25T1G offers the optimal balance of ultra-low-voltage operation (0.8 V), minimal external component count (4 parts), and industry-leading shutdown current (0.6 µA), making it ideal for cost-sensitive, long-life battery systems where input rarely exceeds 1.5 V.

Availability

NCP1400ASN25T1G is available at Aetrix Electronics and suitable for handheld instrumentation, white LED torch lighting, and low-power wireless sensor nodes requiring stable component supply with guaranteed long-term manufacturability and RoHS-compliant packaging.

Supply support for NCP1400ASN25T1G 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 innovation for automotive, industrial, cloud, and intelligent edge applications.

The NCP1400A series was developed specifically for ultra-low-voltage, micropower boost conversion in portable battery-powered devices - emphasizing minimal external components, sub-1-V startup, and sub-µA shutdown current to maximize runtime.

FAQ

What is the minimum input voltage required for NCP1400ASN25T1G to start regulating?

The NCP1400ASN25T1G has a typical minimum startup voltage of 0.8 V, with a maximum of 0.95 V across temperature. This allows reliable operation from a single NiMH or alkaline cell even at end-of-life. Startup voltage decreases by −1.6 mV/°C over −40°C to +85°C, so cold environments may require slightly higher initial voltage. The NCP1400ASN25T1G will continue regulating down to 0.2 V once started.

Can NCP1400ASN25T1G be used with an output voltage other than 2.5 V?

No - the NCP1400ASN25T1G is factory-trimmed for a fixed 2.5 V output using internal feedback resistors. It does not support external resistor programming. However, onsemi offers seven standard variants (e.g., NCP1400ASN19T1G for 1.9 V, NCP1400ASN30T1G for 3.0 V), and custom voltages from 1.8 V to 4.9 V in 100 mV steps can be manufactured upon request. The NCP1400ASN25T1G itself delivers precisely 2.5 V ±2.5%.

How does the CE pin function on NCP1400ASN25T1G, and what happens if it's left floating?

The CE pin on NCP1400ASN25T1G has an internal 150 nA pull-up current source connected to the OUT pin. When left floating, this pulls CE to ~2.5 V, enabling normal operation. To disable, apply ≤0.3 V; to enable actively, apply ≥0.9 V. Applying 0.3–0.9 V places the IC in an undefined state and may cause excessive current draw. The NCP1400ASN25T1G achieves <1.5 µA off-state current when CE is properly pulled low.

What external components are required to implement a functional boost converter with NCP1400ASN25T1G?

A complete NCP1400ASN25T1G boost converter requires exactly four external components: a 22 µH inductor (18–27 µH recommended), a Schottky diode (e.g., MBR0520LT1), a 10 µF input capacitor (low-ESR ceramic or tantalum), and a 68 µF output capacitor (low-ESR tantalum). No feedback resistors, compensation networks, or additional biasing components are needed - the NCP1400ASN25T1G integrates all regulation circuitry internally.

Is NCP1400ASN25T1G compatible with discontinuous conduction mode (DCM) only, and why does that matter?

Yes - the NCP1400ASN25T1G is explicitly designed and compensated for stable operation only in discontinuous conduction mode (DCM). Its internal phase compensation network guarantees stability across full input voltage (0.2–1.5 V), output load (0–100 mA), and temperature (−40°C to +85°C) under DCM. Continuous conduction mode (CCM) is unsupported and may cause oscillation or regulation failure. Designers must select inductor value and operating point to ensure DCM across all conditions.