onsemi NCP1400ASN45T1G

Overview

NCP1400ASN45T1G from onsemi is a fixed-frequency PWM step-up micropower 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 4.5 V, and integrates power MOSFET, oscillator, error amplifier, soft-start, and chip enable - requiring only four external components. It is used in white LED torch lights and handheld instruments where single-cell alkaline or NiMH battery operation is critical.

For engineers reviewing the NCP1400ASN45T1G 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%), quiescent current (53 µA at 4.5 V), and TSOP-5 package compatibility with space-constrained PCB layouts.

Technical Context

The NCP1400ASN45T1G implements a voltage-mode PWM boost architecture operating exclusively in discontinuous conduction mode (DCM) for stable regulation across wide input ranges. Its internal 180 kHz oscillator drives a phase-compensated error amplifier and cycle-by-cycle current-limited power switch, with soft-start ensuring controlled output ramp-up without overshoot.

Regulation is achieved via a factory-trimmed internal feedback resistor network setting V_OUT = 4.5 V (±2.5% at 10 mA, −40°C to +85°C). The CE pin enables shutdown with <1.5 µA off-state current, while the LX pin supports peak currents up to 155 mA and features an integrated 0.8 V voltage limiter to protect the internal MOSFET during overvoltage transients.

Key Specifications

Pinout & Package

TSOP-5 package (Case 483), 5-pin surface-mount, 0.65 mm pitch, lead-free/RoHS compliant. Exposed pad recommended for thermal dissipation.

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 NCP1400ASN45T1G offers lowest BOM count (no feedback resistors), guaranteed 4.5 V fixed output, and optimal trade-off between startup voltage (0.8 V), efficiency, and cost for mid-power portable lighting and instrumentation.

Availability

NCP1400ASN45T1G is available at Aetrix Electronics and suitable for white LED torch lights, handheld instruments, PDAs, and digital camera backlight systems requiring stable component supply with long-term manufacturability and RoHS compliance.

Supply support for NCP1400ASN45T1G 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, with leadership in power management, analog, sensing, and connectivity solutions.

The NCP1400A series was developed specifically for micropower, ultra-low-input-voltage DC-DC conversion in battery-constrained portable devices - emphasizing minimal external components, robust startup behavior, and long operational life from primary cells.

FAQ

What is the minimum input voltage required for NCP1400ASN45T1G to start regulating?

The NCP1400ASN45T1G has a typical minimum startup voltage of 0.8 V, verified across temperature (−40°C to +85°C) and load conditions. It can sustain regulation down to 0.2 V input, making it ideal for deeply discharged alkaline or NiMH cells. This value is measured with zero output load and confirmed in the Absolute Maximum Ratings and Electrical Characteristics tables of the official onsemi datasheet.

Does NCP1400ASN45T1G require external feedback resistors to set its 4.5 V output?

No, the NCP1400ASN45T1G does not require external feedback resistors. Its 4.5 V output is set by a factory-trimmed internal resistor network, delivering ±2.5% accuracy at 10 mA and 25°C. This eliminates component count and layout area - a key advantage over adjustable boost converters like the TPS61022DRVR.

How does the CE pin function on NCP1400ASN45T1G, and what happens if left floating?

The CE pin on NCP1400ASN45T1G enables or disables the regulator: ≥0.9 V enables operation, ≤0.3 V forces shutdown (<1.5 µA current), and floating defaults to enabled via an internal 150 nA pull-up current source tied to the OUT pin. Applying 0.3–0.9 V places the IC in an undefined state and must be avoided.

What is the maximum continuous output current capability of NCP1400ASN45T1G at 4.5 V?

The NCP1400ASN45T1G supports up to 100 mA of continuous output current at 4.5 V under typical conditions (TA = 25°C, VIN = 1.2 V, L = 22 µH, COUT = 68 µF). Derating applies at elevated temperatures or lower input voltages - e.g., ~70 mA at 85°C ambient per Figure 24 and application curves in the datasheet.

Which package type and footprint does NCP1400ASN45T1G use, and is thermal relief recommended?

NCP1400ASN45T1G uses the TSOP-5 package (Case 483), measuring 3.0 × 1.5 mm with 0.65 mm pitch. While the package has no exposed thermal pad in standard configuration, onsemi recommends using a copper pour connected to Pin 4 (GND) beneath the device for improved thermal performance - especially at >50 mA loads - per layout guidance in the datasheet's PCB Layout Hints section.