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Texas Instruments REF1004I-1.2/2K5
- Part No.:
- REF1004I-1.2/2K5
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
REF1004I-1.2/2K5.pdf
- Description:
- IC VREF SHUNT 0.3% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,897
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Product details
Overview
REF1004I-1.2/2K5 from Texas Instruments is a two-terminal micropower bandgap voltage reference diode delivering 1.235 V nominal output with ±4 mV initial accuracy, 20 ppm/°C temperature coefficient, and operation down to 10 µA supply current. It is designed for precision low-power systems including portable medical instrumentation and battery-powered test equipment.
For engineers reviewing the REF1004I-1.2/2K5 datasheet, REF1004I-1.2/2K5 pinout, REF1004I-1.2/2K5 application, or REF1004I-1.2/2K5 equivalent, key selection criteria include its industrial temperature range (–40°C to +85°C), ultra-low dynamic impedance (0.2 Ω typ), long-term stability (20 ppm/kHr), and SOIC-8 packaging compatible with automated assembly.
Technical Context
The REF1004I-1.2/2K5 operates as a shunt-mode reference requiring an external current-setting resistor, with cathode-to-anode reverse breakdown defining its regulation point. Its bandgap core achieves stable 1.235 V output across –40°C to +85°C without trimming or laser calibration.
It exhibits very low wideband noise (60 µV RMS, 10 Hz–10 kHz) and minimal voltage change (±1.5 mV) over 1 mA to 20 mA load current variation, enabling high-resolution ADC/DAC biasing in noise-sensitive signal chains.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 1.235 V (nominal, at 100 µA; min/max 1.225 V / 1.239 V over –40°C to +85°C) |
| Initial Accuracy | ±4 mV (guaranteed at 25°C; enables <0.33% absolute error without calibration) |
| Temp Coefficient | 20 ppm/°C (max; ensures ≤ ±2.5 mV drift over full industrial temperature range) |
| Min Operating Current | 10 µA (enables operation from microamp-level bias sources or high-value resistors) |
| Dynamic Impedance | 0.2 Ω (typ at 100 µA; provides excellent AC rejection for precision analog circuits) |
| Long-Term Stability | 20 ppm/kHr (measured at 25°C; supports >10-year system calibration integrity) |
| Wideband Noise | 60 µV RMS (10 Hz–10 kHz; suitable for 16-bit+ data converters without additional filtering) |
Pinout & Package
REF1004I-1.2/2K5 is housed in an 8-lead SOIC (D) package per JEDEC MS-012, with pin 1 orientation marked by a notch or dot. The device uses only two terminals - Cathode (pins 4 and 7) and Anode (pin 5) - while pins 1–3 and 6 and 8 are no-connect (NC).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (pins 4, 7) | Reference output node | Connected to regulated voltage node; sinks current into external load/resistor network |
| Anode (pin 5) | Current return path | Connected to ground or low-impedance sink; completes shunt regulation loop |
| Pins 1, 2, 3, 6, 8 | No-connect (NC) | Must remain unconnected; no internal connection or function |
Key Features
| Feature | Design Value |
|---|---|
| Industrial temperature range | Specified from –40°C to +85°C (REF1004I grade), enabling deployment in harsh environments without derating |
| Micropower operation | 10 µA minimum operating current allows use with megaohm bias resistors and single-cell battery supplies |
| Low dynamic impedance | 0.2 Ω typical impedance minimizes AC error coupling into sensitive analog front-ends |
| High long-term stability | 20 ppm/kHr drift ensures reference integrity over multi-year field deployments without recalibration |
| Drop-in LT1004 replacement | Pin-compatible and functionally equivalent to LT1004-1.2, simplifying legacy design upgrades |
Applications
| Battery-Powered Test Equipment | Portable Medical Instrumentation |
|---|---|
Use Scenario: Handheld multimeter requiring stable 1.2 V reference for autoranging ADC. IC Role / Device Role / Timing Role: Shunt voltage reference providing excitation and scaling for 16-bit sigma-delta converter. Use Value: ±4 mV initial accuracy and 20 ppm/°C TC enable <0.1% measurement repeatability across ambient temperature shifts. |
Use Scenario: Portable ECG monitor powered by coin cell, needing low-drift reference for analog front-end gain calibration. IC Role / Device Role / Timing Role: Precision bias source for programmable-gain instrumentation amplifier and ADC reference input. Use Value: 10 µA min operating current extends battery life beyond 12 months; 60 µV RMS noise avoids signal degradation in sub-µV biopotential measurements. |
| Portable Communications Devices | A/D and D/A Converters |
Use Scenario: Bluetooth audio headset requiring stable reference for microphone bias and DAC linearity. IC Role / Device Role / Timing Role: Low-noise voltage reference for audio codec power management and signal chain biasing. Use Value: 0.2 Ω dynamic impedance suppresses switching noise from RF section, preserving SNR in 24-bit audio paths. |
Use Scenario: Industrial data acquisition module using 18-bit SAR ADC with external reference input. IC Role / Device Role / Timing Role: Primary reference source for ADC conversion and DAC output scaling. Use Value: 20 ppm/kHr long-term stability eliminates need for periodic factory recalibration in deployed field units. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT1004-1.2CN8#PBF | Same 1.2 V nominal output, ±5 mV initial accuracy, but rated only for 0°C to +70°C (C grade) | Lacks industrial temperature support; unsuitable for outdoor or automotive-adjacent deployments | Select when cost sensitivity outweighs extended temperature requirements and board space permits same SOIC-8 footprint |
| LM385B-1.2/NOPB | 1.235 V nominal, ±1% (±12.4 mV) initial accuracy, higher 50 ppm/°C TC, 10 µA min current | Lower accuracy and stability limit use in high-resolution metrology or medical-grade systems | Choose for non-critical biasing where budget constraints dominate and long-term drift is acceptable |
Compared with LT1004-1.2CN8#PBF, REF1004I-1.2/2K5 adds guaranteed –40°C to +85°C operation and tighter ±4 mV accuracy; versus LM385B-1.2/NOPB, it delivers 3× better tempco and 3× tighter initial tolerance-critical for 16-bit+ converter systems requiring first-time-right calibration.
Availability
REF1004I-1.2/2K5 is available at Aetrix Electronics and suitable for portable medical instrumentation, battery-powered test equipment, and industrial data acquisition systems requiring stable component supply, long-lifecycle availability, and tape-and-reel delivery for SMT production.
Supply support for REF1004I-1.2/2K5 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 company headquartered in Dallas, Texas, specializing in analog, embedded processing, and power management ICs with broad industrial, automotive, and consumer applications.
The REF1004 series was developed by Texas Instruments (originally Burr-Brown) to deliver high-accuracy, micropower shunt references for portable and battery-constrained systems-replacing costly screened parts with a production-ready, temperature-graded solution.
FAQ
What is the operating temperature range of the REF1004I-1.2/2K5?
The REF1004I-1.2/2K5 is characterized for continuous operation from –40°C to +85°C. This industrial-grade temperature rating is confirmed in the official TI datasheet and ordering information table, making it suitable for deployment in demanding environments such as outdoor instrumentation, automotive cabin modules, and industrial edge sensors where ambient extremes are expected. The "I" suffix explicitly denotes this extended range.
Does REF1004I-1.2/2K5 require external components to function?
Yes, REF1004I-1.2/2K5 is a two-terminal shunt reference and requires an external current-setting resistor between the supply rail and the cathode (pins 4/7). The anode (pin 5) connects to ground or a low-impedance return path. No capacitors or active circuitry are mandatory, though a small bypass capacitor (e.g., 1 µF) is recommended at the cathode for improved noise immunity in sensitive applications.
Is REF1004I-1.2/2K5 pin-compatible with LT1004-1.2?
Yes, REF1004I-1.2/2K5 is a documented drop-in replacement for LT1004-1.2 in SOIC-8 packages. Both devices share identical pin assignments (cathode on pins 4/7, anode on pin 5, NC on remaining pins), matching electrical behavior, and compatible biasing requirements. TI's datasheet explicitly states "REF1004 is a drop-in replacement for the LT1004", confirming mechanical and functional interchangeability without PCB changes.
What is the maximum load current the REF1004I-1.2/2K5 can support?
The REF1004I-1.2/2K5 is specified to operate stably up to 20 mA total cathode current. This includes both the required operating current (≥10 µA) and any additional current drawn by the load or downstream circuitry. Exceeding 20 mA risks thermal overload and output voltage deviation beyond specification limits, as confirmed in the Absolute Maximum Ratings and Electrical Characteristics tables of the TI datasheet.
How does the noise performance of REF1004I-1.2/2K5 compare to standard bandgap references?
REF1004I-1.2/2K5 delivers 60 µV RMS wideband noise (10 Hz–10 kHz), significantly lower than typical bandgap references like LM385 (≈100 µV RMS) or TL431 (≈150 µV RMS). This low-noise profile is achieved through optimized bandgap core design and low dynamic impedance (0.2 Ω), making REF1004I-1.2/2K5 especially suitable for high-resolution ADCs and precision sensor signal conditioning where noise directly impacts effective resolution.
REF1004I-1.2/2K5 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 1.235V
- Voltage - Output (Max):
- -
- Current - Output:
- 20 mA
- Tolerance:
- ±0.3%
- Temperature Coefficient:
- 20ppm/°C Typical
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- 60µVrms
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 10 µA
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
REF1004I-1.2/2K5 FAQ
1.How can I place an order for REF1004I-1.2/2K5 through Aetrix?
Please submit a Request for Quotation (RFQ) for REF1004I-1.2/2K5 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 REF1004I-1.2/2K5 reliable?
The price and inventory of REF1004I-1.2/2K5 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for REF1004I-1.2/2K5 is usually 5 days.
3.What payment methods are accepted for REF1004I-1.2/2K5?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for REF1004I-1.2/2K5 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for REF1004I-1.2/2K5?
REF1004I-1.2/2K5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your REF1004I-1.2/2K5 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 REF1004I-1.2/2K5?
For technical support, including REF1004I-1.2/2K5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your REF1004I-1.2/2K5 requirements.
6.How does Aetrix verify that REF1004I-1.2/2K5 is sourced from the original manufacturer or authorized distributors?
All REF1004I-1.2/2K5 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 REF1004I-1.2/2K5 meets industry standards.
7.What is the process for return or replacement of REF1004I-1.2/2K5?
All REF1004I-1.2/2K5 units undergo pre-shipment inspection (PSI). If there is an issue with REF1004I-1.2/2K5, 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 REF1004I-1.2/2K5 part is unused and in its original packaging.
Return procedure for REF1004I-1.2/2K5:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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