onsemi NCP1400ASN45T1

Overview

NCP1400ASN45T1 from onsemi is a micropower fixed-frequency PWM step-up DC-DC switching regulator designed for ultra-low-voltage battery-powered portable devices. It starts up at 0.8 V, operates down to 0.2 V, delivers up to 100 mA output current at 4.5 V, and integrates oscillator, PWM controller, error amplifier, soft-start, and power MOSFET in TSOP-5 package. It powers white LED torch lights and handheld instruments requiring high efficiency with minimal external components.

For engineers reviewing the NCP1400ASN45T1 datasheet, pinout, applications, or equivalent options, key selection criteria include startup voltage (0.8 V), regulated output (4.5 V ±2.5%), switching frequency (180 kHz ±20%), LX peak sink current (100 mA), and CE-controlled shutdown capability.

Technical Context

The NCP1400ASN45T1 implements a fixed-frequency, voltage-mode PWM boost architecture operating exclusively in discontinuous conduction mode (DCM) for stability across full load and input ranges. Its internal phase-compensated error amplifier eliminates need for external compensation networks, while cycle-by-cycle current limiting protects the integrated MOSFET using VLX voltage threshold detection.

Startup and hold behavior is defined by dedicated thresholds: minimum startup voltage is 0.8 V (typical), decreasing −1.6 mV/°C over temperature; minimum hold voltage is 0.3 V (min). The chip enable (CE) pin uses an internal 150 nA pull-up to OUT, allowing floating-pin operation for always-on use or logic-level control with 0.9 V high/0.3 V low thresholds.

Key Specifications

Pinout & Package

Package: TSOP-5 (Case 483), 3.0 mm × 1.5 mm × 1.0 mm body, Pb-free, RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS61022DRVR and MAX17222ETA+, the NCP1400ASN45T1 offers optimal balance of ultra-low startup voltage, integrated compensation, and minimal external component count-making it ideal for space-constrained, low-power portable designs where simplicity and battery longevity are prioritized over peak current or speed.

Availability

NCP1400ASN45T1 is available at Aetrix Electronics and suitable for white LED torch lights, handheld instruments, personal digital assistants, and digital camera backlight systems requiring stable component supply and long-term manufacturability.

Supply support for NCP1400ASN45T1 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 manufacturer specializing in energy-efficient power management, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The NCP1400ASN45T1 belongs to the NCP1400A micropower step-up regulator product line, engineered specifically for ultra-low-voltage battery-powered portable electronics where extended runtime, minimal external components, and guaranteed DCM stability are essential.

FAQ

What is the minimum input voltage required for NCP1400ASN45T1 to start regulating?

The NCP1400ASN45T1 has a typical minimum startup voltage of 0.8 V, with a maximum of 0.95 V across temperature. This allows reliable startup from a single NiMH cell (fully discharged at ~0.9 V) or alkaline cell nearing end-of-life. The device continues operation down to 0.2 V input, enabling full energy extraction from primary batteries. Startup voltage decreases by −1.6 mV/°C over temperature range.

Can NCP1400ASN45T1 be used with a 3.3 V input to generate 4.5 V output?

Yes, the NCP1400ASN45T1 supports input voltages up to 4.5 V and is specified for operation when VIN ≥ 0.7 × VOUT - i.e., ≥3.15 V for 4.5 V output. At 3.3 V input, it delivers full 100 mA output with high efficiency. The internal MOSFET's low R_DS(on) and fixed 180 kHz frequency ensure stable regulation without external compensation, even under varying load conditions.

How does the CE pin function on NCP1400ASN45T1, and what happens if left unconnected?

The CE pin on NCP1400ASN45T1 controls enable/disable state. It features an internal 150 nA pull-up current source tied to the OUT pin, so leaving CE floating results in automatic enable. Applying ≥0.9 V enables normal operation; ≤0.3 V disables the device, reducing quiescent current to 0.6 µA (typ). Voltages between 0.3 V and 0.9 V must be avoided, as they place the IC in an undefined state and may cause excessive supply current draw.

What external components are required to implement a working NCP1400ASN45T1 boost converter?

A functional NCP1400ASN45T1 circuit requires only four external components: an inductor (18–27 µH, e.g., 22 µH), Schottky diode (e.g., MBR0520LT1), input capacitor (10 µF low-ESR ceramic/tantalum), and output capacitor (47–68 µF low-ESR tantalum). No feedback resistors or compensation network are needed - all regulation and stability functions are integrated, minimizing BOM and layout complexity.

Is NCP1400ASN45T1 compatible with continuous conduction mode (CCM) operation?

No, the NCP1400ASN45T1 is explicitly designed and characterized for discontinuous conduction mode (DCM) only. Its internal compensation network guarantees stability across full input/output voltage and load ranges under DCM conditions. Operation in CCM is not supported and may result in instability, oscillation, or unpredictable regulation. Design guidelines specify inductor values (18–27 µH) and operating points that maintain DCM across the intended 0–100 mA load range.