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Texas Instruments LM4040C20QDBZT
- Part No.:
- LM4040C20QDBZT
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
LM4040C20QDBZT.pdf
- Description:
- IC VREF SHUNT 0.5% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:530
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Product details
Overview
LM4040C20QDBZT from Texas Instruments is a precision 2.048V 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 low-power, high-stability reference in analog-to-digital converters and sensor signal conditioning circuits.
For engineers reviewing the LM4040C20QDBZT datasheet, LM4040C20QDBZT pinout, LM4040C20QDBZT application, or LM4040C20QDBZT equivalent, key selection criteria include its extended-temperature C-grade tolerance, no-output-capacitor requirement, low dynamic impedance (0.9Ω typical), and compatibility with high-EMI industrial sensing environments where pin 3 must be tied to anode.
Technical Context
The LM4040C20QDBZT 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 delivers stable output over 45μA–15mA operating current and –40°C to 125°C ambient range without external compensation.
It features low thermal hysteresis (0.08%), 120ppm long-term stability after 1000 hours, and immunity to all capacitive loads - eliminating need for output capacitance while maintaining <1.2mV voltage shift across full current and temperature range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 2.048V nominal at 100μA cathode current - enables exact binary-scaled ADC full-scale calibration (e.g., 12-bit 4096-step systems) |
| Initial Accuracy | ±0.5% max at 25°C - corresponds to ±10.24mV tolerance, sufficient for 10-bit system references |
| Tempco | 100ppm/°C max - contributes ≤±10.24mV drift over –40°C to 125°C span, critical for field transmitter accuracy |
| Min Cathode Current | 45μA typical - supports ultra-low-power battery-operated sensors and energy-harvesting nodes |
| Noise (10Hz–10kHz) | 35μVRMS typical - avoids quantization noise floor elevation in 16-bit+ data acquisition front-ends |
| Dynamic Impedance | 0.9Ω typical at 1mA - ensures <1mV load regulation error with 1mA step changes in sink current |
| Operating Temp Range | –40°C to 125°C - qualified for under-hood automotive, industrial motor control, and oil & gas downhole electronics |
Pinout & Package
SOT-23-3 (DBZ) package: 2.92mm × 1.30mm footprint, surface-mount, lead-free, RoHS-compliant. Thermal resistance RθJA = 206°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Shunt current input / voltage sense node | Connected to regulated supply rail; sinks all excess current to maintain 2.048V drop across device |
| Anode (Pin 2) | Common reference return | Typically grounded; forms reference potential for downstream circuitry (e.g., ADC REF– or op-amp inverting input) |
| NC (Pin 3) | No internal connection | Must float or connect to anode in high-EMI environments (e.g., near switching power supplies or motors) to suppress noise coupling |
Key Features
| Feature | Design Value |
|---|---|
| Zero-output-capacitor operation | Stable with any capacitive load - eliminates BOM cost, board space, and reliability risk of external capacitor |
| Low micropower startup | 45μA minimum cathode current - enables use in always-on wake-up circuits and low-quiescent IoT endpoints |
| High EMI robustness | Pin 3 (NC) configurable as shield tie - reduces noise injection in industrial transmitters near VFDs or RF sources |
| Extended temperature qualification | –40°C to 125°C operation - meets AEC-Q100 Grade 1 requirements for automotive cabin and powertrain modules |
| Low long-term drift | 120ppm shift after 1000h - ensures <0.2% reference degradation over 10-year field deployment in energy infrastructure meters |
Applications
| Industrial Field Transmitter | Automotive Cabin Sensor Node |
|---|---|
Use Scenario: 4–20mA loop-powered pressure/temperature transmitter operating in harsh factory environments. IC Role / Device Role / Timing Role: Shunt reference providing excitation voltage for bridge sensors and reference for 16-bit ΣΔ ADC. Use Value: 100ppm/°C tempco and 0.08% thermal hysteresis ensure <0.1% total error over –40°C to 85°C operating range without calibration. |
Use Scenario: Occupant detection system using capacitive or IR sensors in vehicle dashboard, powered by 12V battery with wide cold-crank voltage swings. IC Role / Device Role / Timing Role: Precision 2.048V reference for SAR ADC digitizing sensor outputs under varying supply and temperature conditions. Use Value: Stable 2.048V output enables exact 12-bit (4096-step) full-scale mapping; 45μA min current allows operation during battery brownouts. |
| Energy Infrastructure Metering | Portable Precision Data Logger |
Use Scenario: ANSI C12.20-compliant smart electricity meter requiring metrology-grade voltage reference over 20-year service life. IC Role / Device Role / Timing Role: Primary shunt reference for polyphase energy measurement ASIC, replacing bulkier bandgap solutions. Use Value: 120ppm long-term stability and ±0.5% initial accuracy meet Class 0.2 metering accuracy requirements without periodic recalibration. |
Use Scenario: Battery-powered environmental logger capturing temperature/humidity with 16-bit resolution in remote locations for >1 year per charge. IC Role / Device Role / Timing Role: Low-noise, low-current reference for successive-approximation ADC and sensor biasing circuitry. Use Value: 35μVRMS noise prevents LSB toggling in 16-bit conversions; 45μA operation extends battery life beyond 18 months on 2000mAh cell. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM4040C20IDBZR | Same electrical specs but industrial-temp (–40°C to 85°C); SOT-23-3 package; no extended-temp qualification | Not suitable for under-hood automotive or high-ambient industrial enclosures exceeding 85°C | Select when cost sensitivity outweighs extended temperature need and ambient stays ≤85°C |
| MAX6008AEUR+T | 2.048V, ±0.2% initial accuracy, 75ppm/°C, 25μVRMS noise, SOT-23-3, –40°C to 85°C only | Higher accuracy and lower noise, but lacks 125°C rating and EMI mitigation pin option | Prefer for lab-grade instrumentation where ultimate noise/accuracy matters more than automotive/industrial temp range |
Compared with LM4040C20IDBZR, LM4040C20QDBZT adds 125°C operation and EMI-hardened pin-3 configuration; compared with MAX6008AEUR+T, it trades 0.3% accuracy and 10μVRMS noise for guaranteed 125°C functionality and robustness in electrically noisy field deployments.
Availability
LM4040C20QDBZT is available at Aetrix Electronics and suitable for industrial field transmitters, automotive cabin sensor nodes, and energy infrastructure metering requiring stable component supply across extended temperature and long lifecycle programs.
Supply support for LM4040C20QDBZT 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 precision, low-power shunt reference applications in space-constrained, thermally demanding systems - emphasizing micropower operation, zero-capacitor stability, and extended-temperature reliability.
FAQ
What is the maximum operating temperature for LM4040C20QDBZT?
The LM4040C20QDBZT is characterized for continuous operation from –40°C to +125°C ambient temperature. This extended temperature range is confirmed in Section 6.7 of the official TI datasheet (SLOS456Q), making it suitable for under-hood automotive and industrial control applications where junction temperatures may exceed 85°C.
Does LM4040C20QDBZT require an output capacitor?
No, LM4040C20QDBZT is stable with all capacitive loads and requires no output capacitor for operation. This is explicitly stated in the Features section and validated across all load conditions in the datasheet's stability characterization - reducing BOM count and PCB area in compact designs.
What is the minimum cathode current needed for regulation in LM4040C20QDBZT?
The LM4040C20QDBZT requires a minimum cathode current of 45μA (typical) to maintain regulation at 2.048V. The datasheet specifies 80μA maximum over full temperature range, ensuring reliable startup even in ultra-low-power sensor nodes powered by energy harvesters or coin cells.
How does pin 3 function on LM4040C20QDBZT?
Pin 3 of LM4040C20QDBZT is a no-connect (NC) terminal with no internal bond. Per TI's recommendation in Figure 5-1 and Table 5-1, it must either float or be connected to the anode (Pin 2) in high-EMI environments - such as near switching regulators or motor drives - to reduce noise coupling into the reference node.
What is the long-term stability specification for LM4040C20QDBZT?
The LM4040C20QDBZT exhibits 120ppm long-term stability after 1000 hours of operation at 25°C with 100μA cathode current, as specified in Sections 6.6 and 6.7 of the TI datasheet. This translates to less than 0.25mV drift over a decade in well-controlled applications, supporting multi-year calibration intervals in utility metering.
LM4040C20QDBZT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 2.048V
- Voltage - Output (Max):
- -
- Current - Output:
- 15 mA
- Tolerance:
- ±0.5%
- Temperature Coefficient:
- 100ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- 35µVrms
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 80 µA
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
LM4040C20QDBZT FAQ
1.How can I place an order for LM4040C20QDBZT through Aetrix?
Please submit a Request for Quotation (RFQ) for LM4040C20QDBZT on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LM4040C20QDBZT reliable?
The price and inventory of LM4040C20QDBZT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM4040C20QDBZT is usually 5 days.
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LM4040C20QDBZT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM4040C20QDBZT order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LM4040C20QDBZT?
For technical support, including LM4040C20QDBZT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM4040C20QDBZT requirements.
6.How does Aetrix verify that LM4040C20QDBZT is sourced from the original manufacturer or authorized distributors?
All LM4040C20QDBZT products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LM4040C20QDBZT meets industry standards.
7.What is the process for return or replacement of LM4040C20QDBZT?
All LM4040C20QDBZT units undergo pre-shipment inspection (PSI). If there is an issue with LM4040C20QDBZT, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LM4040C20QDBZT part is unused and in its original packaging.
Return procedure for LM4040C20QDBZT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM4040C20QDBZT Tags
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