Texas Instruments LM4040C30QDBZR

Overview

LM4040C30QDBZR from Texas Instruments is a precision 3.0V shunt voltage reference in SOT-23-3 (DBZ) package, rated for –40°C to 125°C operation, with ±0.5% initial accuracy, 100ppm/°C temperature coefficient, 35μVRMS wideband noise, and stable operation down to 45μA cathode current. It serves as a compact, low-power voltage reference in high-accuracy analog signal chains.

For engineers reviewing the LM4040C30QDBZR datasheet, LM4040C30QDBZR pinout, LM4040C30QDBZR application, or LM4040C30QDBZR equivalent, key selection criteria include its extended-temperature C-grade tolerance, no-output-capacitor requirement, low dynamic impedance (<0.9Ω), and compatibility with capacitive loads in portable and automotive sensor interfaces.

Technical Context

The LM4040C30QDBZR operates as a two-terminal shunt reference, sinking cathode current (IZ) to maintain a stable 3.0V reverse breakdown voltage across its cathode-anode terminals. Its Zener-zap trimmed bandgap core delivers tight initial accuracy and low thermal drift without external components.

It functions within a 45μA–15mA cathode current range, exhibits <0.9Ω dynamic impedance at 1mA, and maintains output stability across all capacitive loads - eliminating need for output capacitance while supporting fast transient response in ADC biasing and DAC reference circuits.

Key Specifications

Pinout & Package

SOT-23-3 (DBZ) package: 2.92mm × 1.30mm footprint, surface-mount, thermally enhanced plastic body with gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL4050C30QDBZR and MAX6003EUR+T, the LM4040C30QDBZR uniquely balances C-grade accuracy, ultra-low noise, and micropower operation - making it optimal for space-constrained, battery-operated, high-resolution analog systems where both current budget and noise floor are tightly constrained.

Availability

LM4040C30QDBZR is available at Aetrix Electronics and suitable for energy infrastructure monitoring, industrial analog input modules, field transmitter design, and automotive sensor interface applications requiring stable component supply across extended temperature ranges.

Supply support for LM4040C30QDBZR 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 and automotive-qualified components.

The LM4040 series was engineered for high-accuracy, low-power shunt reference applications in harsh environments - targeting industrial automation, automotive sensing, and portable instrumentation where size, stability, and reliability are critical.

FAQ

What is the operating temperature range of the LM4040C30QDBZR?

The LM4040C30QDBZR is specified for continuous operation from –40°C to +125°C ambient temperature, qualifying it for under-hood automotive, industrial motor drives, and outdoor energy infrastructure deployments where thermal extremes are common. This extended range is confirmed in Section 6.13 of the TI datasheet SLOS456Q.

Does the LM4040C30QDBZR require an output capacitor?

No, the LM4040C30QDBZR is inherently stable with all capacitive loads and does not require an output capacitor for regulation - a key advantage over many series references. This simplifies PCB layout and reduces BOM count, especially in space-constrained designs like field transmitters and wearable sensors.

What is the minimum cathode current needed for regulation in the LM4040C30QDBZR?

The LM4040C30QDBZR requires a minimum cathode current of 45μA (typical) to maintain regulation at 3.0V. At temperatures up to 125°C, the maximum required minimum current is 82μA, as documented in Table 6.12 of the datasheet. This enables ultra-low-power operation in battery-backed systems.

How does the LM4040C30QDBZR compare to A-grade or B-grade variants?

The LM4040C30QDBZR offers ±0.5% initial accuracy and 100ppm/°C temperature coefficient - tighter than D-grade (±1.0%) but looser than A-grade (±0.1%) and B-grade (±0.2%). Its C-grade specification targets cost-sensitive, high-volume applications where robustness across –40°C to 125°C matters more than sub-0.2% accuracy.

Is the LM4040C30QDBZR pin-compatible with other LM4040 variants in SOT-23-3?

Yes, all LM4040 variants in the DBZ (SOT-23-3) package - including LM4040A30QDBZR, LM4040B30QDBZR, and LM4040D30QDBZR - share identical pinout (Cathode, Anode, NC) and footprint. This allows drop-in replacement during prototyping or qualification, provided the accuracy and tempco requirements align with the design's error budget.