Texas Instruments LM4040C50IDBZT

Overview

LM4040C50IDBZT from Texas Instruments is a precision micropower shunt voltage reference with 5.0V nominal output, ±0.5% initial accuracy (C grade), 100ppm/°C temperature coefficient, 35μVRMS wideband noise, and stable operation from 45μA to 15mA cathode current. It serves as a compact, low-drift reference in analog signal chains for industrial sensors and data-acquisition front-ends.

For engineers reviewing the LM4040C50IDBZT datasheet, LM4040C50IDBZT pinout, LM4040C50IDBZT application, or LM4040C50IDBZT equivalent, key selection criteria include its SOT-23-3 package compatibility, guaranteed performance across –40°C to 85°C, tight tolerance at minimal operating current, and absence of required output capacitance.

Technical Context

The LM4040C50IDBZT operates as a two-terminal shunt reference, sinking cathode current to maintain a precise 5.0V reverse breakdown voltage across its terminals. Its Zener-zap trimmed silicon design achieves C-grade accuracy without external components, and its low dynamic impedance (≤0.9Ω) ensures stable regulation under varying load conditions.

It functions within a wide cathode current range (45μA–15mA) and requires no output capacitor-enabling direct integration into space-constrained PCB layouts. Thermal hysteresis is limited to 0.08%, and long-term stability is rated at 120ppm over 1000 hours at 25°C.

Key Specifications

Pinout & Package

LM4040C50IDBZT is packaged in a 3-pin SOT-23 (DBZ) case measuring 2.92mm × 1.30mm, optimized for high-density PCB layouts and reflow assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL4050C50IDBZR and MAX6005EUR+T, the LM4040C50IDBZT offers the best balance of low noise (35μVRMS), ultra-low operating current (45μA), and capacitor-free operation-making it optimal for space- and power-constrained industrial sensing nodes.

Availability

LM4040C50IDBZT is available at Aetrix Electronics and suitable for data-acquisition systems, energy infrastructure metering, and field transmitter designs requiring stable component supply, long-lifecycle support, and guaranteed industrial-temperature performance.

Supply support for LM4040C50IDBZT 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 specializing in analog and embedded processing technologies, with decades of expertise in precision reference design.

The LM4040 series was developed to deliver cost-effective, micropower shunt references for industrial and instrumentation applications demanding high accuracy, low noise, and robust thermal performance without external compensation.

FAQ

What is the maximum cathode current rating for LM4040C50IDBZT?

The LM4040C50IDBZT has an absolute maximum cathode current rating of 25mA, as specified in Section 6.1 Absolute Maximum Ratings. However, its recommended operating range is 45μA to 15mA per Section 6.3. Exceeding 15mA may impact long-term stability and thermal performance, so LM4040C50IDBZT should be operated within the 15mA upper limit for reliable, specification-compliant behavior.

Does LM4040C50IDBZT require an output capacitor for stability?

No, LM4040C50IDBZT does not require an output capacitor. As confirmed in the Features section and Section 3 Description, it is explicitly designed to be stable with all capacitive loads-including zero capacitance-and needs no external capacitor for operation. This eliminates board space, cost, and reliability risks associated with capacitor aging or ESR variation in LM4040C50IDBZT implementations.

What is the thermal hysteresis specification for LM4040C50IDBZT?

The thermal hysteresis of LM4040C50IDBZT is 0.08%, defined as the voltage difference measured at 25°C after cycling to –40°C versus after cycling to 125°C. This value is consistent across all grades and packages of the LM4040 family, including LM4040C50IDBZT, and is documented in Tables 6.5–6.22 of the datasheet under the VHYST parameter.

Can LM4040C50IDBZT operate at 125°C ambient temperature?

No, LM4040C50IDBZT is rated for operation from –40°C to +85°C ambient (industrial temperature range). The "Q" suffix variants (e.g., LM4040C50Q) are qualified for –40°C to +125°C. Using LM4040C50IDBZT beyond 85°C ambient violates its specified operating conditions and may result in degraded accuracy, increased drift, or premature failure.

How does the 100ppm/°C temperature coefficient affect LM4040C50IDBZT's output over temperature?

With a 100ppm/°C temperature coefficient, LM4040C50IDBZT's output voltage drift is bounded by ±0.05V over its full –40°C to +85°C range (ΔT = 125°C × 100ppm/°C × 5.0V = ±0.0625V; worst-case overtemperature tolerance is ±1.15% or ±57.5mV per Section 6.5 footnote). This ensures predictable, bounded error in precision analog systems using LM4040C50IDBZT as a reference.