Texas Instruments LM4040D20ILPR

Overview

LM4040D20ILPR from Texas Instruments is a precision micropower shunt voltage reference with a fixed 2.048V output, D-grade (±1.0% initial tolerance, 150ppm/°C tempco), rated for –40°C to 85°C operation, and packaged in SOT-23-3. It delivers low noise (35μVRMS), stable performance across 45μA–15mA cathode current, and requires no output capacitor-ideal for space-constrained analog input modules and portable data-acquisition systems.

For engineers reviewing the LM4040D20ILPR datasheet, LM4040D20ILPR pinout, LM4040D20ILPR application, or LM4040D20ILPR equivalent, key selection factors include its 2.048V reference accuracy at industrial temperature range, cathode current dependency, dynamic impedance under varying load, thermal hysteresis (0.08%), and compatibility with high-capacitance loads without instability.

Technical Context

The LM4040D20ILPR operates as a two-terminal shunt reference, sinking cathode current (IZ) to maintain a precise 2.048V reverse breakdown voltage across its terminals. Its Zener-zap trimmed silicon design achieves ±1.0% initial accuracy and 150ppm/°C temperature coefficient over –40°C to 85°C, with low dynamic impedance (≤1.1Ω at 1mA) ensuring minimal output variation under current transients.

It functions without external compensation, remains stable with all capacitive loads-including large decoupling caps-and exhibits 35μVRMS wideband noise (10Hz–10kHz) at 100μA bias. Long-term stability is 120ppm after 1000 hours, and thermal hysteresis is limited to 0.08% over full temperature cycling.

Key Specifications

Pinout & Package

LM4040D20ILPR is supplied in a 3-pin SOT-23 (DBZ) package, measuring 2.92mm × 1.30mm. Pin 1 is Cathode, Pin 2 is Anode (ground reference), and Pin 3 is NC (no internal connection, must float or tie to anode per EMI guidance).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM4040C20ILPR and MAX6008AEUR+T, the LM4040D20ILPR trades initial accuracy and tempco for lowest cost and widest cathode current range-making it optimal for cost-sensitive, battery-operated, or moderate-accuracy industrial sensing where 1% tolerance is acceptable.

Availability

LM4040D20ILPR is available at Aetrix Electronics and suitable for energy infrastructure monitoring, analog input modules, and field transmitter designs requiring stable component supply with consistent parametric performance across production lots.

Supply support for LM4040D20ILPR 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and personal electronics markets.

The LM4040 series was engineered as a family of precision micropower shunt references targeting cost-effective, space-constrained applications in data acquisition, sensor signal conditioning, and portable instrumentation-emphasizing ease of use, capacitor-free stability, and broad operating current range.

FAQ

What is the maximum cathode current rating for LM4040D20ILPR?

The LM4040D20ILPR has an absolute maximum cathode current rating of 25mA, but its recommended operating range is 45μA to 15mA. Exceeding 15mA may increase self-heating beyond thermal limits, degrading voltage accuracy and long-term stability. Designers should size the series current-limiting resistor to keep IZ within this range under worst-case supply and load conditions.

Does LM4040D20ILPR require an output capacitor for stability?

No, the LM4040D20ILPR is inherently stable with all capacitive loads and does not require an output capacitor. Its internal design eliminates phase-margin concerns associated with traditional shunt references, allowing direct connection to large bulk capacitance (e.g., 10μF ceramic or tantalum) on ADC reference inputs or sensor excitation rails without risk of oscillation.

What is the thermal hysteresis specification for LM4040D20ILPR?

The LM4040D20ILPR exhibits 0.08% thermal hysteresis-defined as the voltage difference measured at 25°C after cycling from –40°C versus after cycling from 125°C. This equates to ≤1.65mV deviation for the 2.048V output, making it suitable for applications requiring repeatable measurements after environmental temperature excursions, such as field-deployed test equipment.

Can LM4040D20ILPR be used in automotive applications?

The LM4040D20ILPR is qualified for the industrial temperature range (–40°C to 85°C), not the extended automotive AEC-Q100 Grade 2 (–40°C to 105°C) or Grade 1 (–40°C to 125°C) ranges. For automotive cabin or engine bay use, TI recommends the LM4040D20Q variant (–40°C to 125°C), which shares identical electrical specs but undergoes additional qualification testing.

How does the 2.048V output of LM4040D20ILPR benefit ADC interfacing?

The 2.048V output of LM4040D20ILPR aligns precisely with binary-scaled full-scale ranges: it enables exact 1mV-per-LSB resolution in 12-bit (4096-step) ADCs and simplifies digital gain calibration in microcontrollers. This eliminates software scaling offsets and reduces firmware complexity in precision measurement systems like digital multimeters and sensor nodes.