Texas Instruments LM4128CMFX-3.3/NOPB

Overview

LM4128CMFX-3.3/NOPB from Texas Instruments is a precision micropower series voltage reference in 5-pin SOT-23 package, delivering 3.3 V output with ±0.5% initial accuracy (C grade), 100 ppm/°C max temperature coefficient, and 60 µA supply current. It features an enable pin for 3 µA shutdown mode, supports up to 20 mA load, and operates from −40°C to +125°C - ideal for battery-powered instrumentation and portable data acquisition systems.

For engineers reviewing the LM4128CMFX-3.3/NOPB datasheet, LM4128CMFX-3.3/NOPB pinout, LM4128CMFX-3.3/NOPB application, or LM4128CMFX-3.3/NOPB equivalent, key selection criteria include dropout voltage (≤400 mV at 10 mA), line regulation (85 ppm/V), load regulation (25–120 ppm/mA), and stability with capacitive loads up to 10 µF without external compensation.

Technical Context

The LM4128CMFX-3.3/NOPB uses an internal band-gap-derived reference architecture optimized for low quiescent current and high PSRR. Its enable-controlled bias network allows seamless transition between active (60 µA) and shutdown (3–7 µA) states without output perturbation.

Designed as a series reference, it eliminates need for external stabilizing capacitors while maintaining stability with output capacitance up to 10 µF - including low-ESR ceramic types. Input-to-output dropout is specified at 175–400 mV across temperature and load, enabling operation from VIN ≥ 3.475 V at 10 mA.

Key Specifications

Pinout & Package

LM4128CMFX-3.3/NOPB is housed in a 5-pin SOT-23 (DBV) package with 0.95 mm pitch, JEDEC MO-178 compliant, and RoHS-compliant matte tin lead finish. Thermal resistance θ_J-A = 220°C/W enables operation at full 20 mA load up to +85°C ambient without derating.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision voltage reference applications.

Compared with REF3033AIDBZR and MAX6033AEUR+T, the LM4128CMFX-3.3/NOPB offers the optimal balance of enable functionality, industrial temperature support, and micropower operation - making it preferred for cost-sensitive, battery-aware designs where ±0.5% accuracy is sufficient.

Availability

LM4128CMFX-3.3/NOPB is available at Aetrix Electronics and suitable for instrumentation front-ends, portable data loggers, and automotive sensor modules requiring stable component supply with guaranteed long-term sourcing.

Supply support for LM4128CMFX-3.3/NOPB 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

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with over 50 years of innovation in precision analog ICs.

The LM4128 series was designed specifically for space-constrained, battery-powered applications demanding low dropout, micropower operation, and robust temperature performance - targeting instrumentation, industrial sensing, and portable test equipment.

FAQ

What is the maximum input voltage for LM4128CMFX-3.3/NOPB?

The LM4128CMFX-3.3/NOPB supports a maximum input voltage of 5.5 V across its full operating temperature range. Exceeding this limit risks permanent damage, as absolute maximum rating is 6 V. For reliable operation, VIN must also stay ≥ VREF + 400 mV (i.e., ≥3.475 V at 10 mA load) to maintain regulation. The device includes built-in overvoltage protection on all pins rated to ±2 kV HBM ESD.

Does LM4128CMFX-3.3/NOPB require an input capacitor?

Yes - LM4128CMFX-3.3/NOPB requires a minimum 0.1 µF ceramic input capacitor (C_IN) connected between VIN and GND. This capacitor is mandatory for stability and noise suppression; omitting it risks oscillation or degraded PSRR. When an output capacitor (C_OUT) is used, C_IN must be ≥ C_OUT. X5R or X7R dielectrics are recommended, and the capacitor must be placed within 2 mm of the VIN and GND pins.

What is the output voltage accuracy specification for LM4128CMFX-3.3/NOPB?

The LM4128CMFX-3.3/NOPB is a C-grade device with ±0.5% initial output voltage accuracy at 25°C, meaning its 3.3 V output falls within 3.2835 V to 3.3165 V before temperature or aging effects. This specification is production-tested and guaranteed - not typical. Over −40°C to +125°C, total error including tempco (100 ppm/°C), load regulation (up to 120 ppm/mA), and line regulation (85 ppm/V) remains within design margins for 12-bit system accuracy.

Can LM4128CMFX-3.3/NOPB drive a 10 µF output capacitor?

Yes - LM4128CMFX-3.3/NOPB is explicitly characterized and guaranteed stable with capacitive loads up to 10 µF, including low-ESR ceramic types. Adding C_OUT improves load transient response when switching between light and heavy loads (e.g., multiplexed ADC sampling), but increases turn-on time: ~78.8 µs for 10 µF vs. ~33.2 µs for 1 µF. No series resistor or isolation is needed.

What is the shutdown current of LM4128CMFX-3.3/NOPB?

The LM4128CMFX-3.3/NOPB draws 3–7 µA in shutdown mode when the EN pin is held low (≤35% of VIN). This ultra-low current enables multi-year battery life in intermittent-sampling applications. The enable threshold is rail-referenced, so EN can be driven directly from the same supply as VIN without level-shifting. Internal pull-up (~2 µA) ensures default activation if EN is left floating.