Texas Instruments LM4040A82IDCKR

Overview

LM4040A82IDCKR from Texas Instruments is a precision micropower shunt voltage reference with 8.192V nominal output, ±0.1% initial accuracy (A grade), 100ppm/°C temperature coefficient, 35μVRMS wideband noise, and stable operation from 45μA to 15mA cathode current. It serves as a high-stability voltage reference in analog-to-digital converters for industrial sensor signal conditioning.

For engineers reviewing the LM4040A82IDCKR datasheet, LM4040A82IDCKR pinout, LM4040A82IDCKR application, or LM4040A82IDCKR equivalent, key selection criteria include guaranteed 8.192V output tolerance over –40°C to 85°C, low-noise performance in battery-powered instrumentation, and SC-70 package compatibility with space-constrained PCB layouts.

Technical Context

The LM4040A82IDCKR operates as a two-terminal shunt reference, sinking cathode current to maintain a precise 8.192V reverse breakdown voltage across its terminals. Its Zener-zap trimmed bandgap core delivers tight initial accuracy and low thermal drift without requiring external capacitors.

It features low dynamic impedance (≤0.9Ω at 1mA), stable performance with all capacitive loads, and thermal hysteresis of only 0.08% - enabling reliable use in precision data acquisition systems where reference stability directly impacts ADC effective resolution.

Key Specifications

Pinout & Package

LM4040A82IDCKR uses the 5-pin SC-70 (DCK) package (2.00mm × 1.25mm), optimized for high-density PCB layouts. Pin 1 = Anode (ground), Pin 2 = Cathode (output), Pin 3 = NC, Pins 4–5 = NC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM4040B82IDCKR, the LM4040A82IDCKR provides 0.1% accuracy at minimal current penalty; versus REF3082AIDBZR, it offers superior initial tolerance and lower operating current but trades off slightly higher tempco and fixed SC-70 pinout.

Availability

LM4040A82IDCKR is available at Aetrix Electronics and suitable for industrial sensor transmitters, precision data acquisition systems, and energy infrastructure monitoring requiring stable component supply and long-term parametric consistency.

Supply support for LM4040A82IDCKR 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 designed specifically for high-accuracy, low-power shunt reference applications where space, stability, and simplicity are critical - targeting portable instrumentation, sensor interfaces, and isolated power monitoring.

FAQ

What is the nominal output voltage of the LM4040A82IDCKR?

The LM4040A82IDCKR has a nominal output voltage of 8.192V, selected to align with binary scaling for 13-bit analog-to-digital conversion. This value is trimmed during wafer sort using Zener-zap technology and is guaranteed within ±0.1% at 25°C. The LM4040A82IDCKR maintains this voltage across its specified operating current range (45μA to 15mA) and temperature range (–40°C to 85°C).

Does the LM4040A82IDCKR require an external output capacitor?

No, the LM4040A82IDCKR is stable with all capacitive loads and does not require an external output capacitor for operation. This eliminates a common BOM item and simplifies layout, especially in space-constrained applications like portable test equipment. The LM4040A82IDCKR achieves this via low dynamic impedance (≤0.9Ω) and internal compensation, as confirmed in TI's official datasheet Section 3 and Figure 8-1.

What is the minimum cathode current needed for regulation in the LM4040A82IDCKR?

The LM4040A82IDCKR requires a minimum cathode current of 45μA (typical) to maintain regulation, with a maximum of 80μA across the full –40°C to 85°C temperature range. This ultra-low current enables use in energy-harvesting and battery-powered systems where standby power must be minimized. The LM4040A82IDCKR remains stable up to 15mA, supporting both micropower and high-accuracy operating points.

How does the LM4040A82IDCKR handle thermal hysteresis?

LM4040A82IDCKR exhibits a thermal hysteresis of 0.08%, defined as the voltage difference measured at 25°C after cycling to –40°C versus after cycling to 125°C. This low hysteresis ensures repeatable reference performance in systems subject to repeated thermal cycling, such as outdoor industrial controllers or automotive cabin modules. The value is consistent across all LM4040 grades and is verified per TI's characterization methodology in Section 6.5–6.22 of the datasheet.

Which package type does the LM4040A82IDCKR use, and how many pins are functional?

The LM4040A82IDCKR uses the SC-70 (DCK) package with five physical pins, but only two are functional: Pin 1 (Anode, grounded) and Pin 2 (Cathode, 8.192V output). Pins 3, 4, and 5 are No Connect (NC); Pin 3 may optionally be tied to the anode in high-EMI environments. This 2.00mm × 1.25mm package enables high-density routing while maintaining compatibility with standard SC-70 assembly processes. The LM4040A82IDCKR pinout is documented in Figure 5-2 and Table 5-1 of the TI datasheet.