onsemi NCP1400ASN33T1G

Overview

NCP1400ASN33T1G from onsemi is a fixed-frequency, micropower PWM step-up DC-DC switching regulator optimized for single- or dual-cell 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 3.3 V, and integrates oscillator, PWM controller, error amplifier, soft-start, and power MOSFET - requiring only four external components. It powers white LED torch lights and handheld instruments where ultra-low input voltage operation and extended battery life are critical.

For engineers reviewing the NCP1400ASN33T1G datasheet, pinout, applications, or equivalent options, key selection criteria include startup voltage (0.8 V), regulated 3.3 V output accuracy (±2.5%), TSOP-5 package footprint, CE-controlled shutdown (1.5 µA off-state current), and discontinuous-conduction-mode stability with no external compensation required.

Technical Context

The NCP1400ASN33T1G implements a voltage-mode PWM boost architecture with an internal 180 kHz oscillator (±20% tolerance, 0.11%/°C tempco) and phase-compensated error amplifier enabling stable regulation in discontinuous conduction mode. Its integrated 350 mA cycle-by-cycle current limit protects the internal MOSFET during overload or inductor saturation.

Startup and hold behavior is defined by dedicated thresholds: minimum startup voltage is 0.8 V (typ), dropping to 0.3 V minimum hold voltage at zero load; soft-start ramps output to ~1.5 V before closed-loop regulation engages. The CE pin features an internal 150 nA pull-up to OUT, allowing floating-enable operation and precise 0.9 V/0.3 V enable/disable logic thresholds.

Key Specifications

Pinout & Package

Package: TSOP-5 (Case 483), Pb-free, moisture sensitivity level 1 (MSL1). Compact 3.0 mm × 1.5 mm outline with 0.95 mm lead pitch and 0.25–0.50 mm lead thickness.

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 NCP1400ASN33T1G uniquely balances sub-1.0 V startup, integrated CE control, fixed-frequency PWM stability, and minimal external component count - making it optimal for cost-sensitive, space-constrained, single-cell portable designs where predictable EMI and long shelf life matter.

Availability

NCP1400ASN33T1G is available at Aetrix Electronics and suitable for white LED torch lights, handheld instruments, personal digital assistants, and electronic games requiring stable component supply with guaranteed long-term manufacturability and RoHS-compliant packaging.

Supply support for NCP1400ASN33T1G 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, delivering silicon solutions for automotive, industrial, cloud, and intelligent edge applications.

The NCP1400A series was designed specifically for ultra-low-voltage, micropower boost conversion in portable battery-operated equipment - emphasizing minimal external components, robust startup behavior, and long operational life from primary and rechargeable cells.

FAQ

What is the minimum input voltage required for NCP1400ASN33T1G to start regulating?

The NCP1400ASN33T1G has a typical minimum startup voltage of 0.8 V, with a maximum of 0.95 V across temperature. This allows reliable operation from nearly depleted alkaline or NiMH cells. Startup voltage decreases slightly with rising temperature (−1.6 mV/°C), so worst-case startup remains below 0.95 V even at +85°C. Below this threshold, the device remains inactive until input rises above the hold voltage (0.3 V).

Can NCP1400ASN33T1G operate with an input voltage lower than 0.8 V?

Yes - the NCP1400ASN33T1G can continue regulating down to a minimum hold voltage of 0.3 V (at zero load), enabling extended runtime after startup. However, it cannot initiate regulation below 0.8 V; once started, it sustains output as input declines, provided load current remains within capability limits defined by the input-output voltage ratio and inductor size.

What is the purpose of the NC pin (Pin 3) on NCP1400ASN33T1G?

Pin 3 is a no-connect (NC) terminal with no internal bond wire or circuit connection. It must remain unconnected on the PCB - neither routed nor soldered. Leaving it floating or tied to ground may cause mechanical stress or unintended coupling; the datasheet explicitly specifies "no internal connection" and recommends no PCB treatment.

How does the CE pin function on NCP1400ASN33T1G, and what happens if it's left floating?

The CE pin on NCP1400ASN33T1G has an internal 150 nA pull-up current source connected to the OUT pin. When left floating, this pulls CE to ~3.3 V, enabling normal regulation. Applying ≥0.9 V enables the device; applying ≤0.3 V disables it (reducing current to 1.5 µA). Voltages between 0.3 V and 0.9 V place the IC in an undefined state and must be avoided.

Is external compensation required for stable operation of NCP1400ASN33T1G?

No - the NCP1400ASN33T1G includes an internally phase-compensated error amplifier optimized for stable operation in discontinuous conduction mode across its full input/output voltage and load range. External compensation components are unnecessary and not recommended; adding them may destabilize the control loop or degrade transient response.