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Analog Devices Inc. REF191ES-REEL
- Part No.:
- REF191ES-REEL
- Manufacturer:
- Analog Devices Inc.
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
REF191ES-REEL.pdf
- Description:
- IC VREF SERIES 0.1% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,504
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Product details
Overview
REF191ES-REEL from Analog Devices is a precision micropower low-dropout voltage reference IC delivering 2.048 V output with ±2 mV initial accuracy, 5 ppm/°C max temperature coefficient, and 45 μA max supply current - used as a stable excitation source for high-resolution ADCs and portable sensor signal chains.
For engineers reviewing the REF191ES-REEL datasheet, REF191ES-REEL pinout, REF191ES-REEL application, or REF191ES-REEL equivalent, this device is selected for battery-powered instrumentation requiring sub-10 ppm/°C drift over −40°C to +85°C, sleep-mode power gating, and low-headroom operation down to 100 mV dropout.
Technical Context
The REF191ES-REEL implements a patented curvature-corrected band gap core with laser-trimmed thin-film resistors to achieve its 5 ppm/°C max TC and ±2 mV initial accuracy across the extended industrial range. Its SLEEP pin enables TTL/CMOS-compatible shutdown, reducing quiescent current to ≤15 μA while disabling output.
It operates with dropout as low as 0.95 V at 2 mA load and maintains 4 ppm/mA load regulation and 4 ppm/V line regulation (E grade, 25°C), supporting precision analog front-ends where supply variation and load transients must not perturb reference stability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Output Voltage | 2.048 V - precisely matches 12-bit full-scale LSB step for common SAR ADCs and DACs. |
| Initial Accuracy | ±2 mV maximum (E grade) - eliminates need for system-level calibration in portable 12–14-bit data acquisition. |
| Temp Coefficient | 5 ppm/°C maximum (E grade, −40°C to +85°C) - ensures ≤105 ppm total drift over full industrial range. |
| Supply Current | 45 μA maximum - enables multi-year operation from coin-cell batteries in wireless sensor nodes. |
| Sleep Mode Current | 15 μA maximum - allows duty-cycled sensing with <1% average power overhead from reference circuitry. |
| Dropout Voltage | 0.95 V at 2 mA - permits use with 3.0 V supplies while maintaining regulation for 2.048 V output. |
| Output Noise | 20 μV p-p (0.1 Hz to 10 Hz) - supports 16-bit effective resolution without additional filtering. |
Pinout & Package
REF191ES-REEL is housed in an 8-lead SOIC_N (SOIC-8 narrow-body) package with exposed pad (suffix 'ES' per Analog Devices ordering guide). Pin 1 and Pin 5 are factory test points (TP) and must remain unconnected in application circuits.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (TP) | Factory Zener trim point | No user connection; internal laser trimming node - floating or tied to GND/VS causes undefined behavior. |
| 2 (VS) | Positive supply input | Accepts 3.0 V to 15 V; minimum headroom 0.95 V at 2 mA load for regulation. |
| 3 (SLEEP) | Digital enable control | Active-low TTL/CMOS input; <0.8 V disables output and reduces IQ to ≤15 μA. |
| 4 (GND) | Analog ground reference | Must be star-connected to system AGND; bypass capacitor (1 μF) connects here and OUTPUT. |
| 5 (TP) | Factory Zener trim point | No user connection; identical restriction as Pin 1 - leave unconnected. |
| 6 (NC) | No connect | Internally unused; must be left floating (not tied to GND or VS). |
| 7 (NC) | No connect | Internally unused; must be left floating. |
| 8 (OUTPUT) | Precision voltage output | 2.048 V ±2 mV; requires 1 μF ceramic capacitor to GND for stability and noise reduction. |
Key Features
| Feature | Design Value |
|---|---|
| Curvature-corrected band gap core | Enables 5 ppm/°C max TC without external compensation components or oven control. |
| Laser-trimmed thin-film resistors | Guarantees ±2 mV initial accuracy without post-package calibration or sorting. |
| Low-dropout architecture | Supports operation from 3.0 V rails with only 0.95 V headroom - ideal for single-cell Li-ion or 3.3 V systems. |
| Integrated sleep mode | Reduces supply current to ≤15 μA while fully disabling output - simplifies power sequencing in ultra-low-power designs. |
| Short-circuit protected output | Withstands indefinite output-to-GND faults without damage or parameter shift - improves field reliability. |
Applications
| Portable Instrumentation | High-Resolution Data Acquisition |
|---|---|
|
Use Scenario: Handheld multimeter with 16-bit sigma-delta ADC and coin-cell power. IC Role / Device Role / Timing Role: Primary voltage reference for ADC conversion and internal DAC calibration. Use Value: 20 μV p-p noise and 5 ppm/°C TC enable true 16-bit ENOB without averaging or firmware correction. |
Use Scenario: Isolated industrial sensor transmitter with loop-powered 4–20 mA output. IC Role / Device Role / Timing Role: Stable excitation source for bridge sensors and reference for 24-bit ADC. Use Value: 45 μA supply current and sleep mode allow microcontroller to power-cycle the reference during idle periods, cutting system standby power by >30%. |
| Solar-Powered Remote Sensors | Smart Transmitter Calibration |
|
Use Scenario: Wireless soil moisture node powered by small solar panel and supercapacitor buffer. IC Role / Device Role / Timing Role: Reference for ratiometric measurement of resistive sensor array and LDO feedback divider. Use Value: 0.95 V dropout enables regulation from 2.5 V storage voltage - maximizing usable energy from low-voltage harvesting. |
Use Scenario: Field-deployable pressure transmitter requiring NIST-traceable calibration at installation. IC Role / Device Role / Timing Role: On-board precision reference for self-test and zero/span adjustment routines. Use Value: ±2 mV initial accuracy and 1.2 mV long-term stability (1000 h @ 125°C) reduce recalibration frequency to once per 5 years. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar precision voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ADR3412ARJZ-R7 | Fixed 1.2 V output; 3 ppm/°C TC; 3.5 μA typical IQ; no sleep mode. | Lower power but incompatible output voltage; unsuitable where 2.048 V is required for ADC full-scale alignment. | Select only if system uses 1.2 V reference and ultra-low IQ dominates over TC and accuracy. |
| MAX6126AASA+T | 2.048 V output; 3 ppm/°C TC; 120 μA IQ; no sleep mode; higher cost. | Superior TC and noise (12 μV p-p), but lacks sleep control and consumes >2.5× more quiescent current. | Choose when lowest possible drift is critical and sleep functionality is unnecessary or implemented externally. |
Compared with REF191ES-REEL, ADR3412ARJZ-R7 trades output voltage compatibility for ultra-low power, while MAX6126AASA+T delivers better TC and noise at the expense of sleep capability and higher IQ - making REF191ES-REEL optimal for 2.048 V, battery-gated, industrial-grade applications.
Availability
REF191ES-REEL is available at Aetrix Electronics and suitable for portable instrumentation, high-resolution data acquisition, and solar-powered remote sensors requiring stable component supply with guaranteed long-term parametric consistency.
Supply support for REF191ES-REEL 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
Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA, with design and manufacturing expertise spanning precision signal conditioning, power management, and RF technologies.
The REF19x series was engineered specifically for micropower, low-dropout precision voltage referencing in space-constrained, battery-operated, and wide-temperature industrial systems - prioritizing TC, initial accuracy, and sleep-mode efficiency over raw speed or output drive.
FAQ
What is the nominal output voltage and initial accuracy of the REF191ES-REEL?
The REF191ES-REEL provides a nominal output voltage of 2.048 V with initial accuracy of ±2 mV maximum (E grade) at 25°C. This tolerance is specified before solder heat effects and remains stable across −40°C to +85°C, enabling direct use in 12-bit ADC applications without trimming.
Does the REF191ES-REEL require an external output capacitor, and if so, what value?
Yes, the REF191ES-REEL requires a 1 μF ceramic capacitor connected between the OUTPUT and GND pins for stability and noise reduction. This capacitor is mandatory per the datasheet and prevents oscillation under varying load conditions - omitting it risks output instability and degraded noise performance.
How does the SLEEP pin function on the REF191ES-REEL, and what is its effect on supply current?
The SLEEP pin on the REF191ES-REEL is an active-low TTL/CMOS-compatible control input. Driving it below 0.8 V disables the output and reduces supply current to ≤15 μA. At logic high (>2.4 V), the REF191ES-REEL operates normally with ≤45 μA supply current - enabling precise power gating in duty-cycled systems.
What package type is used for the REF191ES-REEL, and are Pins 1 and 5 user-accessible?
The REF191ES-REEL uses an 8-lead SOIC_N (narrow-body) package with exposed pad ('ES' suffix). Pins 1 and 5 are factory test points for Zener-trim calibration and must remain unconnected in all applications - connecting them risks output inaccuracy or device malfunction.
Can the REF191ES-REEL operate with a supply voltage only slightly above its 2.048 V output?
Yes, the REF191ES-REEL is a low-dropout voltage reference with a minimum dropout of 0.95 V at 2 mA load. It can therefore regulate stably from a 3.0 V supply (3.0 V − 2.048 V = 0.952 V headroom), making it suitable for single-cell Li-ion or regulated 3.3 V systems where headroom is constrained.
REF191ES-REEL Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- REF19
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Reference Type:
- Series
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 2.048V
- Voltage - Output (Max):
- -
- Current - Output:
- 30 mA
- Tolerance:
- ±0.1%
- Temperature Coefficient:
- 5ppm/°C
- Noise - 0.1Hz to 10Hz:
- 20µVp-p
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- 3V ~ 15V
- Current - Supply:
- 45µA
- Current - Cathode:
- -
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
REF191ES-REEL FAQ
1.How can I place an order for REF191ES-REEL through Aetrix?
Please submit a Request for Quotation (RFQ) for REF191ES-REEL 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 REF191ES-REEL reliable?
The price and inventory of REF191ES-REEL are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for REF191ES-REEL is usually 5 days.
3.What payment methods are accepted for REF191ES-REEL?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for REF191ES-REEL transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for REF191ES-REEL?
REF191ES-REEL orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your REF191ES-REEL 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 REF191ES-REEL?
For technical support, including REF191ES-REEL datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your REF191ES-REEL requirements.
6.How does Aetrix verify that REF191ES-REEL is sourced from the original manufacturer or authorized distributors?
All REF191ES-REEL 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 REF191ES-REEL meets industry standards.
7.What is the process for return or replacement of REF191ES-REEL?
All REF191ES-REEL units undergo pre-shipment inspection (PSI). If there is an issue with REF191ES-REEL, 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 REF191ES-REEL part is unused and in its original packaging.
Return procedure for REF191ES-REEL:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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