Texas Instruments LM4140CCM-1.2

Overview

LM4140CCM-1.2 from Texas Instruments is a high-precision, low-noise, low-dropout series voltage reference with 1.25 V nominal output, 0.1% initial accuracy, 10 ppm/°C temperature coefficient (C grade), 20 mV typical dropout at 1 mA, and enable-controlled shutdown consuming ≤1 µA. It serves as a stable excitation source in precision data acquisition systems requiring minimal supply headroom and ultra-low drift.

For engineers reviewing the LM4140CCM-1.2 datasheet, LM4140CCM-1.2 pinout, LM4140CCM-1.2 application, or LM4140CCM-1.2 equivalent, key selection criteria include guaranteed 1.8 V minimum input operation, 1 µF mandatory output capacitor for stability, ±0.1% output tolerance over 0°C to 70°C, and enable-driven fast turn-on (<200 µs) with internal output discharge.

Technical Context

The LM4140CCM-1.2 employs EEPROM-trimmed CMOS DACs for curvature-corrected temperature compensation and output voltage trimming-enabling sub-bandgap 1.25 V output with 10 ppm/°C max drift across 0°C–70°C. Its P-channel pass transistor architecture supports operation down to VIN = VREF + 20 mV (typical) while maintaining regulation under 1–8 mA load.

It integrates an active enable input that fully disables output and reduces supply current to ≤1 µA, with logic-compatible thresholds (V_H ≥ 0.8×V_IN, V_L ≤ 0.4 V). The device requires external 1 µF output capacitance with specified ESR range for loop stability and transient response, and exhibits 2.2 µV_PP (0.1–10 Hz) noise performance scaled linearly with V_REF.

Key Specifications

Pinout & Package

LM4140CCM-1.2 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 LM4140CCM-1.2, REF3012AIDBZR trades enable control and ultra-low dropout for lower cost and smaller footprint, while ADR3412ARJZ-R7 matches tempco but demands higher input voltage-making LM4140CCM-1.2 uniquely suited for 1.8 V–powered, enable-driven, low-drift precision systems.

Availability

LM4140CCM-1.2 is available at Aetrix Electronics and suitable for portable instrumentation, medical sensor modules, and automotive battery monitoring systems requiring stable component supply, long-lifecycle support, and guaranteed parametric compliance.

Supply support for LM4140CCM-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

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The LM4140 series was designed specifically to deliver sub-bandgap precision references with EEPROM-based trimming-targeting high-accuracy, low-power data acquisition and portable measurement equipment where traditional bandgap references fall short in voltage flexibility and drift performance.

FAQ

What is the minimum input voltage required for stable operation of the LM4140CCM-1.2?

The LM4140CCM-1.2 operates stably with a minimum input voltage of 1.8 V-just 550 mV above its 1.25 V output-due to its 20 mV typical dropout voltage at 1 mA. This allows direct use with single-cell lithium batteries or low-voltage DC rails without pre-regulation. Operation below 1.8 V risks loss of regulation and increased output drift, as confirmed in Section 6.3 of the SNVS053F datasheet.

Does the LM4140CCM-1.2 require an output capacitor, and if so, what are the specifications?

Yes, the LM4140CCM-1.2 requires a 1 µF ceramic or tantalum capacitor between VREF and GND for loop stability and transient response, as mandated in Section 8.1.2 of the datasheet. Capacitor ESR must fall within the range shown in Figure 23 (1-µF ESR Range), typically 0.1–10 Ω. Omitting this capacitor causes oscillation and output inaccuracy; values below 0.2 µF risk instability across temperature.

How does the enable pin function on the LM4140CCM-1.2, and what happens to the output during shutdown?

The LM4140CCM-1.2 enable pin (Pin 3) turns the device on when pulled high (≥0.8×V_IN) and off when pulled low (≤0.4 V). During shutdown, output voltage drops to 0 V within microseconds, and supply current falls to ≤1 µA. Critically, internal circuitry actively discharges the output capacitor to ground-preventing residual voltage from affecting downstream circuitry during power-down sequences.

What is the temperature coefficient specification for the LM4140CCM-1.2, and over what range is it guaranteed?

The LM4140CCM-1.2 is a C-grade device with a maximum temperature coefficient of 10 ppm/°C over the full operating ambient temperature range of 0°C to 70°C, as specified in Table 6.5 of the SNVS053F datasheet. This translates to a worst-case output drift of ±875 µV across the range-enabling high-accuracy applications without per-unit calibration.

Can the LM4140CCM-1.2 drive an 8 mA load continuously, and what is the impact on dropout voltage?

Yes, the LM4140CCM-1.2 is rated to source up to 8 mA continuously, as stated in the Pin Functions table (Pin 6: VREF, "Capable of sourcing up to 8 mA"). At 8 mA and 25°C, dropout voltage rises to 160–235 mV (typical 160 mV), per Section 6.5. This remains well within safe operating limits and maintains regulation-though designers must ensure VIN ≥ 1.25 V + 235 mV = 1.485 V minimum at worst case.