Texas Instruments LM4140CCMX-2.5

Overview

LM4140CCMX-2.5 from Texas Instruments is a high-precision, low-noise, low-dropout series voltage reference delivering 2.5 V output with ±0.1% initial accuracy, 10 ppm/°C temperature coefficient (C grade), and 20 mV typical dropout at 1 mA. It features an enable pin for power management, consumes only 230 µA in active mode and ≤1 µA in shutdown, and is optimized for precision analog signal chains in portable instrumentation and data acquisition systems.

For engineers reviewing the LM4140CCMX-2.5 datasheet, LM4140CCMX-2.5 pinout, LM4140CCMX-2.5 application, or LM4140CCMX-2.5 equivalent, key selection considerations include its 2.5 V fixed output, SOIC-8 package, ultra-low 2.2 µV_PP (0.1–10 Hz) noise, 1 µF mandatory output capacitor requirement, and enable-controlled ON/OFF functionality with <200 µs turn-on time.

Technical Context

The LM4140CCMX-2.5 uses EEPROM-trimmed CMOS DACs for curvature-corrected temperature compensation and output voltage trimming-enabling sub-bandgap voltage options like 2.5 V while achieving 10 ppm/°C drift over 0°C to 70°C. Its P-channel pass transistor architecture supports operation down to VIN = VREF + 20 mV (typical), with internal discharge circuitry actively sinking the output capacitor during shutdown.

It operates as a series reference requiring external 1 µF output capacitance for loop stability and transient response, with strict ESR constraints validated for tantalum and ceramic capacitors. The enable pin accepts logic-level control (V_H ≥ 0.8×VIN, V_L ≤ 0.4 V), and the device enters full shutdown with I_S(OFF) ≤ 1 µA across temperature.

Key Specifications

Pinout & Package

LM4140CCMX-2.5 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 precision voltage reference applications.

Compared with REF5025IDR and ADR4525BRZ, LM4140CCMX-2.5 trades minor accuracy and noise performance for ultra-low 230 µA supply current and integrated enable control-making it uniquely suitable for portable, battery-operated systems requiring precision without sacrificing runtime.

Availability

LM4140CCMX-2.5 is available at Aetrix Electronics and suitable for precision data acquisition, portable instrumentation, medical sensor interfaces, and industrial process monitoring requiring stable component supply across production lifecycles.

Supply support for LM4140CCMX-2.5 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, power management, and signal chain solutions.

The LM4140 series was designed specifically for high-accuracy, low-power voltage reference applications in portable, battery-powered, and space-constrained systems-emphasizing low dropout, enable control, and factory-trimmed stability without laser calibration.

FAQ

What is the minimum input voltage required for LM4140CCMX-2.5 to regulate at 2.5 V?

The LM4140CCMX-2.5 requires a minimum input voltage of VREF + dropout voltage. With a typical dropout of 20 mV at 1 mA, the minimum functional VIN is 2.52 V. At full 8 mA load and over temperature, dropout rises to 400 mV, so VIN must be ≥2.9 V under worst-case conditions to maintain regulation. Always verify against the Electrical Characteristics table in the TI SNVS053F datasheet.

Does LM4140CCMX-2.5 require an output capacitor, and what type is recommended?

Yes, LM4140CCMX-2.5 requires a 1 µF output capacitor for loop stability and transient response. TI validates solid tantalum (e.g., Kemet T491A105M010AS) and multilayer ceramic capacitors (e.g., Murata GRM42-6Y5V225Z16) with appropriate ESR. Aluminum electrolytics are discouraged due to ESR drift at low temperatures. The capacitor must be placed adjacent to pins 6 (VREF) and 1/4/7/8 (GND) with minimal trace length.

How does the enable pin function on LM4140CCMX-2.5, and what happens during shutdown?

The enable pin (pin 3) controls LM4140CCMX-2.5 operation: driven high (≥0.8×VIN) for normal output, low (≤0.4 V) for shutdown. During shutdown, LM4140CCMX-2.5 actively discharges the output capacitor to ground via internal circuitry, ensuring rapid and predictable VREF collapse. Supply current drops to ≤1 µA, and VREF settles to near 0 V within microseconds-critical for power-gated sensor systems.

What is the output noise specification of LM4140CCMX-2.5, and how is it measured?

LM4140CCMX-2.5 delivers 2.2 µV_PP (peak-to-peak) output noise over the 0.1 Hz to 10 Hz bandwidth, measured per TI SNVS053F test conditions: COUT = 1 µF, VIN = 5 V, ILOAD = 0 mA, TA = 25°C. This low 1/f noise is critical for high-resolution measurements in weigh scales and medical sensors. Total RMS noise (0.1 Hz–100 kHz) is approximately 7 µV_RMS, per Figure 12 in the datasheet.

Can LM4140CCMX-2.5 drive an ADC reference input directly, and what is its maximum load current?

Yes, LM4140CCMX-2.5 can directly drive most ADC reference inputs, with a guaranteed output drive capability of ±8 mA. For example, it fully supports the 1 µA max input current of TI's ADS124S08 or Analog Devices' AD7793 without buffering. Load regulation is specified at 1–8 mA, with worst-case drift of 150 ppm/mA over temperature-translating to <1.25 mV error at 8 mA load on the 2.5 V output.