onsemi NCP105AMX345TCG

Overview

NCP105AMX345TCG from onsemi is a 150 mA, fixed-output 3.45 V low-dropout linear regulator with high PSRR (70 dB at 1 kHz), ultra-low quiescent current (50 µA typ.), and active output discharge. It operates from 1.7 V to 5.5 V input, delivers ±1% output accuracy at room temperature, and is optimized for noise-sensitive, space-constrained battery-powered systems such as smartphone camera modules and portable medical sensors.

For engineers reviewing the NCP105AMX345TCG datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage at 150 mA (105–165 mV @ 3.45 V), soft-start slew-rate option (normal speed, per A/B variant), thermal shutdown (160°C), and stability with 1 µF ceramic output capacitor - all validated for XDFN4 package integration.

Technical Context

The NCP105AMX345TCG implements a PMOS pass transistor architecture enabling low dropout and reverse-current protection via inherent body diode management. Its dynamic quiescent current adjustment maintains ultra-low IQ across load conditions, while internal bandgap reference and error amplifier ensure ±1% output accuracy over −40°C to +85°C.

It integrates enable logic with precise thresholds (VEN_HI = 0.9 V, VEN_LO = 0.4 V), thermal shutdown with 20°C hysteresis, current limiting (200–600 mA), and - in A/C variants - active output discharge via 100 Ω internal FET. The device is stable without ESR requirements on COUT and supports fast load transients due to optimized control loop design.

Key Specifications

Pinout & Package

Package: XDFN4 (1.0 mm × 1.0 mm, 0.65 mm pitch, Case 711AJ), thermally enhanced with exposed pad tied to GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-3302E/TT and XC6210B345MR-G, the NCP105AMX345TCG uniquely combines exact 3.45 V output, integrated thermal shutdown, active discharge, and industry-standard XDFN4 footprint - making it optimal for camera and medical sensor designs requiring both precision and robustness.

Availability

NCP105AMX345TCG is available at Aetrix Electronics and suitable for smartphone camera modules, portable medical sensors, industrial wireless nodes, and wearable fitness trackers requiring stable component supply with guaranteed long-term manufacturability.

Supply support for NCP105AMX345TCG 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 specializing in energy-efficient power management, analog, and sensing solutions for automotive, industrial, and consumer markets.

The NCP105AMX345TCG belongs to onsemi's high-PSRR, low-IQ LDO family designed specifically for battery-powered imaging, medical, and IoT edge devices demanding precision voltage regulation in ultra-small footprints.

FAQ

What is the output voltage tolerance of the NCP105AMX345TCG over temperature?

The NCP105AMX345TCG maintains ±1% output voltage accuracy at room temperature (25°C). Over the full operating junction temperature range (−40°C to +85°C), output deviation remains within ±2% for VOUT > 2.0 V - confirmed in Electrical Characteristics Table on page 3 of the datasheet. This ensures reliable performance in ambient-variable environments like outdoor wearables or vehicle-mounted sensors.

Does the NCP105AMX345TCG support active output discharge, and how does it function?

Yes, the NCP105AMX345TCG (as an "A" variant) supports active output discharge. When EN is driven below 0.4 V, an internal 100 Ω FET connects OUT to GND, rapidly discharging the output capacitor. This prevents floating voltages that could cause latch-up or false wake-up in downstream logic - a critical feature for camera modules and medical sensors requiring controlled power sequencing.

What is the minimum recommended output capacitor for stable operation of the NCP105AMX345TCG?

The NCP105AMX345TCG is stable with a minimum 1 µF X5R or X7R ceramic capacitor on the OUT pin. The datasheet confirms stability down to 0.47 µF (accounting for DC bias and temperature derating), but 1 µF is the recommended value for guaranteed performance across all load and temperature conditions - especially important in compact layouts where capacitor size is constrained.

How does the NCP105AMX345TCG achieve high PSRR despite its small package?

The NCP105AMX345TCG achieves 70 dB PSRR at 1 kHz through a combination of high-gain error amplifier design, optimized internal compensation, and PMOS pass transistor topology that minimizes gate-drive sensitivity to input ripple. Its PSRR remains effective up to 100 kHz, and can be extended further with proper COUT selection and PCB layout - verified in Figures 24–27 of the datasheet.

Can the NCP105AMX345TCG be used with input voltages below 2.0 V?

Yes - the NCP105AMX345TCG operates from 1.7 V to 5.5 V input. At VIN = 1.7 V, it sustains 3.45 V output only if dropout is met (i.e., VIN ≥ VOUT + VDO). Since VDO is 105–165 mV @ 150 mA, the device can regulate down to VIN ≈ 3.555 V under full load. However, at light loads, it remains functional even at VIN = 1.7 V - though output will drop out of regulation. This makes it suitable for partial-discharge battery scenarios where VIN may dip temporarily.