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Analog Devices Inc. REF191ESZ-REEL
- Part No.:
- REF191ESZ-REEL
- Manufacturer:
- Analog Devices Inc.
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
REF191ESZ-REEL.pdf
- Description:
- IC VREF SERIES 0.1% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:688
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Product details
Overview
REF191ESZ-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 30 mA output current capability. It operates from supplies as low as 100 mV above output voltage, supports sleep mode (15 μA), and targets high-accuracy analog signal chains in portable and solar-powered instrumentation.
For engineers reviewing the REF191ESZ-REEL datasheet, REF191ESZ-REEL pinout, REF191ESZ-REEL application, or REF191ESZ-REEL equivalent, key selection criteria include dropout voltage at 10 mA (1.25 V), load regulation (4 ppm/mA), line regulation (4 ppm/V), and SOIC_N package compatibility for space-constrained industrial sensor nodes and precision ADC/DAC biasing.
Technical Context
The REF191ESZ-REEL uses a patented curvature-corrected band gap core with laser-trimmed thin-film resistors to achieve stable 2.048 V output across −40°C to +85°C. Its internal SLEEP pin enables TTL/CMOS-compatible shutdown, reducing supply current to ≤15 μA while disabling output.
Designed for low-noise, low-drift applications, it requires a 1 μF output-to-GND capacitor for stability and delivers 20 μVP-P (0.1 Hz–10 Hz) noise. Dropout voltage is specified at 1.25 V (VS = 3.3 V, ILOAD = 10 mA), enabling operation from single Li-ion or dual alkaline cells.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Output Voltage | 2.048 V - Matches standard 12-bit DAC full-scale reference and simplifies ratiometric ADC calibration. |
| Initial Accuracy | ±2 mV maximum - Enables <1 LSB error in 12-bit systems without post-calibration. |
| Temp Coefficient | 5 ppm/°C max - Drift ≤ ±0.42 mV over −40°C to +85°C, critical for unheated field instruments. |
| Supply Current | 45 μA max - Supports multi-year battery life in wireless sensor transmitters. |
| Sleep Mode Current | 15 μA max - Allows periodic wake-up sampling with minimal quiescent drain. |
| Dropout Voltage | 1.25 V @ 10 mA - Operates from 3.3 V rail with ≥1.25 V headroom, compatible with common LDO outputs. |
| Load Regulation | 4 ppm/mA - Output shift ≤8 μV per mA load change, essential for dynamic load ADC drivers. |
Pinout & Package
REF191ESZ-REEL is housed in an 8-lead SOIC_N (SOIC-8 narrow-body) package, pin-compatible with industry-standard SOIC-8 footprints and suitable for reflow assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (TP) | Factory Test Point | Reserved for Zener zap trimming; must remain unconnected in circuit. |
| 2 (VS) | Positive Supply Input | Accepts 2.148 V to 15 V; minimum headroom 100 mV above 2.048 V output. |
| 3 (SLEEP) | Digital Enable Control | TTL/CMOS-compatible input; low = output disabled, current ≤15 μA. |
| 4 (GND) | Analog Ground Reference | Return path for output and internal circuitry; requires low-impedance connection to system ground plane. |
| 5 (TP) | Factory Test Point | Reserved for Zener zap trimming; must remain unconnected in circuit. |
| 6 (NC) | No Connect | Internally unused; leave floating or tie to GND per layout best practice. |
| 7 (NC) | No Connect | Internally unused; leave floating or tie to GND per layout best practice. |
| 8 (OUTPUT) | Precision Voltage Output | 2.048 V source; requires 1 μF ceramic bypass capacitor to GND for stability and noise reduction. |
Key Features
| Feature | Design Value |
|---|---|
| Curvature-Corrected Band Gap Core | Enables 5 ppm/°C tempco without external compensation, reducing BOM count in portable calibrators. |
| Laser-Trimmed Thin-Film Resistors | Guarantees ±2 mV initial accuracy without post-production calibration, cutting test time in volume production. |
| Low-Dropout Operation (100 mV min) | Supports direct regulation from single-cell batteries or low-headroom LDOs, extending usable battery voltage range. |
| Integrated Sleep Mode Control | Reduces current to 15 μA via logic-level pin, enabling microcontroller-gated power cycling in IoT endpoints. |
| Short-Circuit Protected Output | Withstands indefinite output short to GND without damage, improving robustness in field-deployed sensor modules. |
Applications
| Portable Instrumentation | High-Resolution Data Acquisition |
|---|---|
|
Use Scenario: Handheld multimeters and portable gas analyzers requiring stable reference under varying battery voltage and ambient temperature. IC Role / Device Role / Timing Role: Primary 2.048 V reference for 16-bit SAR ADCs and precision op-amp bias networks. Use Value: 5 ppm/°C tempco and 45 μA supply current enable >10-hour runtime on AA cells with <0.01% full-scale drift over operating range. |
Use Scenario: Industrial PLC analog input modules digitizing 4–20 mA sensor signals with 16+ bit resolution. IC Role / Device Role / Timing Role: Ratiometric reference for delta-sigma ADCs, ensuring measurement accuracy independent of supply rail variation. Use Value: 4 ppm/mA load regulation prevents gain error when driving multiplexed ADC input buffers with dynamic switching loads. |
| Solar-Powered Remote Sensors | Loop-Powered Transmitters |
|
Use Scenario: Wireless environmental sensors powered by small photovoltaic cells with highly variable output voltage (2.2–4.0 V). IC Role / Device Role / Timing Role: Low-headroom reference enabling operation down to 2.148 V supply while maintaining 2.048 V output stability. Use Value: 1.25 V dropout at 10 mA allows continuous reference operation during low-light conditions where battery backup is absent. |
Use Scenario: 4–20 mA loop-powered pressure/temperature transmitters with strict 3.5 mA total loop budget. IC Role / Device Role / Timing Role: Micropower reference supplying bias to signal conditioning circuitry within the loop's current limit. Use Value: 45 μA supply current leaves >3.45 mA available for sensor excitation, signal amplification, and loop driver-maximizing design margin. |
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 1.200 V output; 3 ppm/°C max tempco; 30 μA supply current; SOT-23-5 package. | Lower voltage output limits use in 12-bit+ systems requiring 2.048 V; smaller footprint but no sleep mode. | Select ADR3412ARJZ-R7 only if 1.2 V suffices and board space is constrained; REF191ESZ-REEL remains preferred for 2.048 V compliance and sleep control. |
| MAX6126AASA21+ | 2.048 V output; 3 ppm/°C max tempco; 120 μA supply current; no sleep mode; SOIC-8 package. | Higher quiescent current reduces battery life; superior tempco but lacks power-gating capability. | Choose MAX6126AASA21+ when ultimate drift performance is prioritized over power savings; REF191ESZ-REEL better suits duty-cycled or energy-harvested systems. |
Compared with ADR3412ARJZ-R7 and MAX6126AASA21+, REF191ESZ-REEL uniquely balances 2.048 V output, 5 ppm/°C tempco, 45 μA supply current, and active sleep control-making it optimal for portable, solar, and loop-powered applications where voltage, power, and feature set must coexist.
Availability
REF191ESZ-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 continuity.
Supply support for REF191ESZ-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, serving industrial, automotive, communications, and healthcare markets since 1965.
The REF19x series was developed to address demand for micropower, low-dropout, high-accuracy voltage references in battery-operated and energy-constrained systems-emphasizing precision, stability, and ease of integration.
FAQ
What is the nominal output voltage of the REF191ESZ-REEL?
The REF191ESZ-REEL provides a precise 2.048 V nominal output voltage, optimized for compatibility with 12-bit and higher-resolution analog-to-digital converters. This value is laser-trimmed during manufacturing and maintained across −40°C to +85°C with ≤5 ppm/°C temperature coefficient. The REF191ESZ-REEL output remains stable under load changes up to 30 mA and supply variations within its specified dropout margin.
Does the REF191ESZ-REEL support sleep mode, and how is it activated?
Yes, the REF191ESZ-REEL features a dedicated SLEEP pin (Pin 3) that enables ultra-low-power operation. Applying a logic-low level (≤0.8 V) to this pin disables the output and reduces supply current to ≤15 μA. A logic-high level (≥2.4 V) restores normal operation with ≤45 μA supply current. This function is fully compatible with standard microcontroller GPIO outputs and supports duty-cycled sensing architectures using the REF191ESZ-REEL.
What package type and pin configuration does the REF191ESZ-REEL use?
The REF191ESZ-REEL is supplied in an 8-lead SOIC_N (narrow-body SOIC-8) package, with standardized 1.27 mm pitch and JEDEC MS-012AC outline. Its pinout includes VS (Pin 2), SLEEP (Pin 3), GND (Pin 4), OUTPUT (Pin 8), two factory test points (Pins 1 and 5), and two no-connect terminals (Pins 6 and 7). The REF191ESZ-REEL pin assignment matches industry-standard SOIC-8 footprints and supports automated optical inspection and reflow soldering.
What is the minimum supply voltage required for the REF191ESZ-REEL to regulate properly?
The REF191ESZ-REEL requires a minimum supply headroom of 100 mV above its 2.048 V output to maintain regulation-meaning VS must be ≥2.148 V under no-load conditions. At 10 mA load, the dropout voltage rises to 1.25 V (VS ≥ 3.298 V); at 30 mA, it reaches 1.55 V (VS ≥ 3.598 V). These values are verified across −40°C to +85°C and define the practical lower limit of input rails when designing with the REF191ESZ-REEL.
Is an output capacitor required for stable operation of the REF191ESZ-REEL?
Yes, a 1 μF ceramic capacitor must be placed between the OUTPUT (Pin 8) and GND (Pin 4) pins of the REF191ESZ-REEL for stable operation and optimal noise performance. This capacitor suppresses high-frequency oscillation, reduces 0.1 Hz–10 Hz noise to 20 μVP-P, and improves transient response to load steps. X7R or C0G dielectrics are recommended; placement should minimize trace inductance and avoid shared return paths with noisy digital circuits using the REF191ESZ-REEL.
REF191ESZ-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:
- Active
- 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
REF191ESZ-REEL FAQ
1.How can I place an order for REF191ESZ-REEL through Aetrix?
Please submit a Request for Quotation (RFQ) for REF191ESZ-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 REF191ESZ-REEL reliable?
The price and inventory of REF191ESZ-REEL are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for REF191ESZ-REEL is usually 5 days.
3.What payment methods are accepted for REF191ESZ-REEL?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for REF191ESZ-REEL transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for REF191ESZ-REEL?
REF191ESZ-REEL orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your REF191ESZ-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 REF191ESZ-REEL?
For technical support, including REF191ESZ-REEL datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your REF191ESZ-REEL requirements.
6.How does Aetrix verify that REF191ESZ-REEL is sourced from the original manufacturer or authorized distributors?
All REF191ESZ-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 REF191ESZ-REEL meets industry standards.
7.What is the process for return or replacement of REF191ESZ-REEL?
All REF191ESZ-REEL units undergo pre-shipment inspection (PSI). If there is an issue with REF191ESZ-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 REF191ESZ-REEL part is unused and in its original packaging.
Return procedure for REF191ESZ-REEL:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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