Texas Instruments LM4140ACM-2.0/NOPB

Overview

LM4140ACM-2.0/NOPB from Texas Instruments is a high-precision, low-noise, low-dropout series voltage reference delivering 2.048 V output with ±0.1% initial accuracy, 3 ppm/°C temperature coefficient (A grade), 20 mV typical dropout at 1 mA, and 230 µA typical supply current. It features an enable pin for power management and supports precision analog signal chains in battery-powered instrumentation.

For engineers reviewing the LM4140ACM-2.0/NOPB datasheet, LM4140ACM-2.0/NOPB pinout, LM4140ACM-2.0/NOPB application, or LM4140ACM-2.0/NOPB equivalent, key selection criteria include output stability under load variation, thermal hysteresis (20 ppm), ultra-low 0.1 Hz–10 Hz noise (2.2 µV_PP), and compatibility with 1 µF output capacitance for loop stability.

Technical Context

The LM4140ACM-2.0/NOPB uses EEPROM-trimmed CMOS DACs for curvature-corrected temperature compensation and output voltage trimming-enabling sub-bandgap 2.048 V output with 3 ppm/°C drift over 0°C to 70°C. Its P-channel pass transistor architecture supports operation down to VIN = VREF + 20 mV (typical) while maintaining regulation.

Enable functionality provides fast turn-on (<200 µs) and active discharge of the output capacitor during shutdown, reducing IQ to ≤1 µA. The device requires a mandatory 1 µF output capacitor for stability and transient response, with ESR constraints validated for tantalum, ceramic, and aluminum electrolytic types.

Key Specifications

Pinout & Package

LM4140ACM-2.0/NOPB is housed in an 8-pin SOIC package (4.90 mm × 3.91 mm body size) with exposed pad not electrically connected. Pin functions are validated per TI SNVS053F Rev F datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with REF5020AIDR and ADR4520BRZ, LM4140ACM-2.0/NOPB uniquely combines enable control, ultra-low 230 µA operating current, and 0.1% accuracy in SOIC - making it optimal for portable, event-driven sensing where power gating and moderate precision are jointly critical.

Availability

LM4140ACM-2.0/NOPB is available at Aetrix Electronics and suitable for portable instrumentation, precision data acquisition, battery-powered medical sensors, and automotive cabin monitoring requiring stable component supply with traceable lot history and extended lifecycle support.

Supply support for LM4140ACM-2.0/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 company specializing in analog and embedded processing technologies, with leadership in precision analog ICs since 1951.

The LM4140 product line was engineered to deliver sub-bandgap reference voltages with EEPROM-based trimming - targeting portable, battery-operated, and high-resolution measurement systems needing low power, low noise, and tight thermal stability.

FAQ

What is the minimum input voltage required for stable operation of the LM4140ACM-2.0/NOPB?

The LM4140ACM-2.0/NOPB requires a minimum input voltage of VREF + 20 mV (2.068 V) at 1 mA load and 25°C, with worst-case dropout of 45 mV over 0°C–70°C. This allows direct operation from regulated 2.1 V or higher supplies, such as those derived from single-cell Li-ion batteries with integrated LDOs. Operation below this headroom risks loss of regulation and increased output drift.

Does the LM4140ACM-2.0/NOPB require an output capacitor, and what type is recommended?

Yes, the LM4140ACM-2.0/NOPB mandates a 1 µF output capacitor between VREF and GND for loop stability and transient response. Solid tantalum capacitors (e.g., Kemet T491A105M010AS) are verified for stability; multilayer ceramics (≥0.2 µF) may be used if ESR meets TI's specified range (Figure 23). Aluminum electrolytics are discouraged below 0°C due to ESR rise causing instability.

How does the enable pin function on the LM4140ACM-2.0/NOPB, and what are its voltage thresholds?

The enable pin on the LM4140ACM-2.0/NOPB controls output state: logic high (≥0.8 × VIN) enables VREF output and normal supply current; logic low (≤0.4 V) disables output and reduces supply current to ≤1 µA while actively discharging the output capacitor. The pin draws ≤2 nA, allowing direct interface with MCU GPIOs without level-shifting.

What is the output noise performance of the LM4140ACM-2.0/NOPB, and how does it scale with voltage?

The LM4140ACM-2.0/NOPB delivers 2.2 µV_PP (0.1–10 Hz) noise for the 1.024 V option; noise scales linearly with output voltage. For the 2.048 V version, output noise is 4.4 µV_PP. This low noise floor supports 16-bit+ resolution in SAR and sigma-delta ADCs without external filtering, preserving dynamic range in precision sensor interfaces.

Can the LM4140ACM-2.0/NOPB drive 8 mA continuously, and what is the impact on dropout voltage?

Yes, the LM4140ACM-2.0/NOPB is rated to source up to 8 mA continuously. At 8 mA and 25°C, dropout voltage increases to 160–235 mV depending on grade, rising to 400 mV maximum over 0°C–70°C. Designers must ensure VIN ≥ VREF + 400 mV under worst-case load and temperature to maintain regulation and specified accuracy.