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Analog Devices Inc. ADR391BUJZ-R2
- Part No.:
- ADR391BUJZ-R2
- Manufacturer:
- Analog Devices Inc.
- Category:
- Voltage Reference
- Package:
- SOT-23-5 Thin, TSOT-23-5
- Datasheet:
-
ADR391BUJZ-R2.pdf
- Description:
- IC VREF SERIES 0.16% TSOT5
- Quantity:
- Payment:
- Shipping:
Inventory:3,514
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Product details
Overview
ADR391BUJZ-R2 from Analog Devices is a micropower, low-noise 2.5 V precision band gap voltage reference with shutdown control, housed in a 5-lead TSOT package. It delivers ±4 mV initial accuracy (B grade), 9 ppm/°C temperature coefficient, 5 μVp-p (0.1 Hz–10 Hz) output noise, and operates from as low as 2.8 V supply with only 300 mV dropout - ideal for high-accuracy ADC/DAC biasing in portable medical instrumentation.
For engineers reviewing the ADR391BUJZ-R2 datasheet, ADR391BUJZ-R2 pinout, ADR391BUJZ-R2 application, or ADR391BUJZ-R2 equivalent, key selection criteria include guaranteed 5 mA output current, ultralow 3 μA shutdown current, no external capacitor requirement, −40°C to +125°C automotive-grade operating range, and force/sense output architecture enabling precise remote sensing in noisy environments.
Technical Context
The ADR391BUJZ-R2 implements a patented curvature-corrected band gap core referenced to the output (not ground), minimizing ground noise coupling. Its dual-output topology-VOUT(FORCE) and VOUT(SENSE)-enables Kelvin sensing for load regulation compensation across PCB traces or connectors.
Shutdown is TTL/CMOS-compatible: logic low on SHDN disables the reference, placing VOUT in high-impedance state while drawing only 3 μA. The device requires no external bypass capacitors for stability but supports up to 10 μF capacitive loads and maintains regulation down to 300 mV headroom above 2.5 V output.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 2.5 V nominal, ±4 mV max initial error at 25°C (B grade) |
| Tempco | 9 ppm/°C over −40°C to +125°C - enables <±0.25 mV drift across full automotive range |
| Noise (0.1–10 Hz) | 5 μVp-p - preserves SNR in 16-bit+ data acquisition systems |
| Dropout Voltage | 300 mV - allows operation from single-cell Li-ion (2.8 V min) or 3.3 V rail with margin |
| Supply Current | 140 μA max in operation; 3 μA in shutdown - extends battery life in always-on sensors |
| Output Current | 5 mA - drives SAR ADC reference inputs, op-amp bias networks, and small DACs directly |
| Line Regulation | 25 ppm/V - holds output stable despite input rail variation in unregulated battery systems |
Pinout & Package
ADR391BUJZ-R2 uses a compact 5-lead TSOT (UJ suffix) package, 1.6 mm × 1.6 mm × 0.55 mm, with exposed pad for thermal performance (θJA = 230°C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: GND | Reference ground return | Low-impedance analog ground path; must be connected to clean system ground plane |
| 2: SHDN | Active-low shutdown control | TTL/CMOS-compatible input; ≤0.8 V disables output, ≥2.4 V enables operation |
| 3: VOUT (SENSE) | Feedback sense node | Connects directly to load point to compensate for trace IR drop - enables true remote sensing |
| 4: VOUT (FORCE) | Output drive node | Delivers regulated 2.5 V; connects to load through separate trace when SENSE is used |
| 5: VIN | Power input | Accepts 2.8 V to 15 V; minimum 300 mV headroom required above 2.5 V output |
Key Features
| Feature | Design Value |
|---|---|
| Force/Sense output architecture | Eliminates voltage error from PCB trace resistance - critical for precision sensor signal chains |
| No external capacitor required | Reduces BOM count and board area; stable with 0–10 μF capacitive loads |
| Ultralow 5 μVp-p noise (0.1–10 Hz) | Enables high-resolution measurements without post-filtering in portable instruments |
| Automotive-grade temp range | Qualified for −40°C to +125°C operation - suitable for under-hood and ADAS modules |
| 3 μA shutdown current | Permits deep-sleep modes in battery-powered IoT nodes without compromising wake-up speed |
Applications
| Portable Medical Instrumentation | Battery-Powered Data Acquisition |
|---|---|
Use Scenario: Handheld ECG monitor with 24-bit sigma-delta ADC requiring stable 2.5 V reference for analog front-end. IC Role / Device Role / Timing Role: Precision voltage reference providing excitation and ADC conversion基准 for biopotential measurement. Use Value: 9 ppm/°C tempco and 5 μVp-p noise ensure <±1 LSB error across temperature and time, meeting IEC 60601-2-27 clinical accuracy requirements. | Use Scenario: Wireless vibration sensor node powered by coin cell, sampling accelerometer via 16-bit SAR ADC. IC Role / Device Role / Timing Role: Low-power reference source enabling accurate ratiometric conversion independent of battery voltage decay. Use Value: 140 μA operating current and 300 mV dropout allow continuous operation down to 2.8 V, extending usable battery life by >30% versus legacy references. |
| Industrial Process Control | Automotive Sensor Modules |
Use Scenario: Loop-powered 4–20 mA transmitter with HART modulation, using internal DAC requiring stable reference. IC Role / Device Role / Timing Role: Primary voltage reference for current-loop DAC and diagnostic ADC channels. Use Value: Force/sense outputs maintain <±0.01% reference accuracy despite 100 mΩ loop wiring resistance, eliminating calibration drift in field installations. | Use Scenario: Tire pressure monitoring system (TPMS) module operating in wheel well with wide ambient temperature swings. IC Role / Device Role / Timing Role: Reference for pressure sensor bridge excitation and microcontroller ADC. Use Value: −40°C to +125°C rating and 50 ppm long-term stability (1000 hrs) ensure consistent pressure readings over vehicle lifetime without recalibration. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar precision voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6126AASA25+ | 2.5 V, 3 ppm/°C max tempco, 1.2 μA quiescent current, but no shutdown and no force/sense outputs | Lacks remote sensing capability and shutdown - unsuitable for dynamic power management or high-accuracy remote loads | Select when ultra-low drift (<3 ppm/°C) is prioritized over power control and sensing flexibility |
| REF3425RTER | 2.5 V, 10 ppm/°C tempco, 4.5 μA shutdown current, force/sense outputs, but 150 μA operating current and 400 mV dropout | Higher dropout and quiescent current limit use in sub-3 V battery systems | Select when TI ecosystem compatibility is required and 400 mV headroom is acceptable |
Compared with MAX6126AASA25+ and REF3425RTER, the ADR391BUJZ-R2 uniquely balances ultralow noise (5 μVp-p), force/sense architecture, and micropower shutdown (3 μA) in a TSOT package - making it optimal for space-constrained, battery-operated precision systems demanding both accuracy and power agility.
Availability
ADR391BUJZ-R2 is available at Aetrix Electronics and suitable for portable medical instrumentation, battery-powered data acquisition, and industrial process controls requiring stable component supply with guaranteed long-term availability and automotive-grade reliability.
Supply support for ADR391BUJZ-R2 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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.
The ADR39x family was designed specifically for micropower, high-accuracy voltage referencing in space- and energy-constrained applications - emphasizing low noise, low dropout, and robust operation across extended temperature ranges.
FAQ
What is the maximum load current supported by the ADR391BUJZ-R2?
The ADR391BUJZ-R2 delivers up to 5 mA of output current while maintaining specified accuracy and regulation. This is sufficient to drive most precision ADC reference inputs, DAC buffers, and low-power op-amp bias networks. Exceeding 5 mA may degrade line/load regulation and increase output voltage error beyond datasheet limits.
Does the ADR391BUJZ-R2 require an external output capacitor for stability?
No, the ADR391BUJZ-R2 is internally compensated and does not require an external output capacitor for stability. It remains stable with capacitive loads from 0 μF to 10 μF. However, a 0.1 μF ceramic capacitor is recommended at the VOUT(FORCE) pin to improve transient response under dynamic load conditions.
How does the force/sense configuration of the ADR391BUJZ-R2 improve accuracy?
The ADR391BUJZ-R2's separate VOUT(FORCE) and VOUT(SENSE) pins enable Kelvin sensing: VOUT(SENSE) connects directly to the load point, allowing the internal regulator to compensate for voltage drop across PCB traces or connectors. This eliminates IR errors and maintains ±4 mV initial accuracy at the actual load, even with 100 mΩ series resistance.
What is the minimum input voltage required for the ADR391BUJZ-R2 to regulate properly?
The ADR391BUJZ-R2 requires a minimum supply voltage of 2.8 V - that is, 300 mV above its 2.5 V output - to maintain regulation. Below this headroom, the output voltage drops linearly with VIN. This low dropout enables operation from single-cell lithium batteries or tightly regulated 3.3 V rails with margin.
Can the ADR391BUJZ-R2 be used in automotive applications?
Yes, the ADR391BUJZ-R2 is qualified for automotive-grade operation across −40°C to +125°C and features 9 ppm/°C temperature coefficient, 50 ppm long-term stability (1000 hours), and robust ESD protection. It meets requirements for engine control, ADAS sensors, and infotainment subsystems where precision and reliability are critical.
ADR391BUJZ-R2 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Package/Case:
- SOT-23-5 Thin, TSOT-23-5
- Series:
- ADR39
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Reference Type:
- Series
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 2.5V
- Voltage - Output (Max):
- -
- Current - Output:
- 5 mA
- Tolerance:
- ±0.16%
- Temperature Coefficient:
- 9ppm/°C
- Noise - 0.1Hz to 10Hz:
- 5µVp-p
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- 2.8V ~ 15V
- Current - Supply:
- 140µA
- Current - Cathode:
- -
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TSOT-23-5
ADR391BUJZ-R2 FAQ
1.How can I place an order for ADR391BUJZ-R2 through Aetrix?
Please submit a Request for Quotation (RFQ) for ADR391BUJZ-R2 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 ADR391BUJZ-R2 reliable?
The price and inventory of ADR391BUJZ-R2 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ADR391BUJZ-R2 is usually 5 days.
3.What payment methods are accepted for ADR391BUJZ-R2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ADR391BUJZ-R2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ADR391BUJZ-R2?
ADR391BUJZ-R2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ADR391BUJZ-R2 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 ADR391BUJZ-R2?
For technical support, including ADR391BUJZ-R2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ADR391BUJZ-R2 requirements.
6.How does Aetrix verify that ADR391BUJZ-R2 is sourced from the original manufacturer or authorized distributors?
All ADR391BUJZ-R2 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 ADR391BUJZ-R2 meets industry standards.
7.What is the process for return or replacement of ADR391BUJZ-R2?
All ADR391BUJZ-R2 units undergo pre-shipment inspection (PSI). If there is an issue with ADR391BUJZ-R2, 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 ADR391BUJZ-R2 part is unused and in its original packaging.
Return procedure for ADR391BUJZ-R2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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