STMicroelectronics LM4041AICT-1.2

Overview

LM4041AICT-1.2 from STMicroelectronics is a precision micropower shunt voltage reference delivering a stable 1.225 V output with ±0.1% initial accuracy at 25 °C, 40 µA operating current, and 100 ppm/°C max temperature coefficient in SOT323-5L package. It serves as a low-power, space-constrained voltage reference in battery-operated instrumentation and energy management systems.

For engineers reviewing the LM4041AICT-1.2 datasheet, LM4041AICT-1.2 pinout, LM4041AICT-1.2 application, or LM4041AICT-1.2 equivalent, key selection criteria include ultra-low quiescent current, tight initial tolerance, capacitive-load stability, and industrial temperature range compliance.

Technical Context

The LM4041AICT-1.2 operates as a two-terminal shunt reference, regulating voltage by sinking adjustable cathode current while maintaining fixed 1.225 V across its terminals. Its design enables stable operation with capacitive loads up to 1 µF and supports minimum regulation current of 40 µA at 25 °C.

It features low wideband noise (60 µV_RMS, 10 Hz–10 kHz), static impedance ≤1 Ω, and long-term stability of 120 ppm over 1000 hours - critical for high-resolution data acquisition and precision analog front-ends where drift and noise directly impact measurement fidelity.

Key Specifications

Pinout & Package

LM4041AICT-1.2 is housed in a 5-pin SOT323-5L surface-mount package. Pins 2, 4, and 5 must be left floating or tied to the Anode (pin 1) to improve PCB layout noise immunity per ST's recommendation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431ACDBVR and MAX6008AEUR+T, LM4041AICT-1.2 uniquely combines 1.225 V output, ±0.1% accuracy, 40 µA operation, and guaranteed capacitive-load stability - making it optimal for space-constrained, battery-powered precision measurement where reference integrity directly impacts system-level accuracy certification.

Availability

LM4041AICT-1.2 is available at Aetrix Electronics and suitable for battery-operated equipment, data acquisition systems, and energy management applications requiring stable component supply, consistent parametric performance, and long-term lifecycle support.

Supply support for LM4041AICT-1.2 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The LM4041 series belongs to ST's precision analog portfolio, engineered specifically for low-power, high-accuracy voltage referencing in portable and embedded measurement systems where size, current, and stability are critical constraints.

FAQ

What is the maximum cathode voltage the LM4041AICT-1.2 can withstand?

The LM4041AICT-1.2 has an absolute maximum cathode voltage (V_K) of 8 V, as specified in ST's datasheet Table 1. Exceeding this voltage risks permanent device damage. In normal operation, cathode voltage equals the 1.225 V reference plus voltage drop across the series bias resistor - so bias resistor selection must ensure V_K stays within safe limits under all load and supply conditions.

Can LM4041AICT-1.2 drive a 1 µF capacitor directly without oscillation?

Yes - ST explicitly characterizes and guarantees stability with capacitive loads up to 1 µF, as confirmed in Figure 4 (Output Impedance vs. Frequency) and the "Stable when used with capacitive loads" feature bullet. No series isolation resistor is required, unlike many older shunt references. This enables direct decoupling at the ADC reference pin without compromising transient response or noise performance.

How does the 100 ppm/°C temperature coefficient translate to actual voltage drift?

With a nominal 1.225 V output, a 100 ppm/°C coefficient yields a worst-case drift of ±122.5 µV per °C. Over the full industrial range (-40 to +85 °C, ΔT = 125 °C), total drift is ≤±15.3 mV - or ±1.25% of nominal output. This is verified in Figure 2 (V_K vs. Temperature) and aligns with the "100 ppm/°C maximum" specification in the Features section.

Why do pins 2, 4, and 5 require connection to the Anode or floating?

Pins 2, 4, and 5 are no-connect (NC) terminals in the SOT323-5L package. ST recommends leaving them floating or tying them to pin 1 (Anode) to reduce noise coupling through parasitic capacitance in high-EMI PCB layouts. This practice improves PSRR and reduces susceptibility to switching noise from adjacent DC-DC converters - a design requirement validated in ST's application testing and documented in the Pin Configuration section (Figure 1 note).