ADR3450ARJZ-R7 is a precision, low-power, 5.0 V fixed-output voltage reference designed and manufactured by Analog Devices Inc. (ADI). It belongs to the high-accuracy, low-drift ADR34xx family, engineered specifically for high-resolution data acquisition systems, precision instrumentation, and industrial applications, where stable, low-noise, and highly accurate voltage references are critical for maximizing ADC/DAC performance, sensor calibration, and analog signal chain fidelity — especially in systems requiring a 5 V reference (e.g., legacy DAQ, op-amp gain-setting, ratiometric sensor excitation, or mixed-signal SoCs with 5 V I/O domains).
The “ARJZ” suffix denotes the 8-lead SOT-23 package (2.9 mm × 1.6 mm) — an ultra-compact, surface-mount footprint ideal for space-constrained designs; the “-R7” indicates 7-inch tape-and-reel packaging (3,000 units per reel), Pb-free, RoHS-compliant, and qualified for industrial temperature range (–40°C to +125°C junction temperature).
⚠️ Critical Clarification:
The ADR3450 is not a standard bandgap reference. It is a buried Zener-based, laser-trimmed, precision reference, delivering:
- Ultra-low temperature coefficient: 3 ppm/°C (max) — identical drift performance to the ADR3430, enabling sub-16-bit accuracy over wide temperature ranges without recalibration;
- Exceptional initial accuracy: ±0.1% (±5 mV) max at 25°C, with tight distribution (±0.06% typical);
- Low output noise: 12 µVP-P (0.1–10 Hz), 4.5 µVRMS (10 Hz–10 kHz) — exceptionally quiet for a 5 V reference (most competing 5 V refs exceed 25 µVP-P);
- Low quiescent current: 115 µA (typ.), 140 µA (max) — supports multi-year battery life in portable meters and IoT sensors while maintaining full 5 V accuracy;
- High load regulation & robust drive capability: Supports ±10 mA output current, with < 10 ppm/mA line/load regulation — suitable for driving ADC reference inputs, precision op-amp circuits, or multiple DACs simultaneously.
It operates from a supply voltage of 5.3 V to 15 V, features reverse-voltage protection, and is stable with no external capacitor required, though a 1 µF ceramic cap is recommended for optimal noise performance.
Introduction
The ADR3450ARJZ-R7 delivers laboratory-grade 5 V reference performance in the smallest standard precision reference package:
🔹 Metrology-grade stability: 3 ppm/°C max drift means only ±0.36 mV total drift over –40°C to +125°C — enabling single-point calibration for 18+ bit systems using a 5 V reference rail;
🔹 Uniquely low noise for 5 V: At 12 µVP-P (0.1–10 Hz), it is ～2× quieter than most competitive 5 V references (e.g., REF5050: 25 µVP-P) — preserving ENOB in high-SFDR data converters like AD7177, ADS127L01, or LTC2500;
🔹 True low-power precision: 115 µA IQ at full 5 V accuracy — unlike many "low-power" references that degrade drift or noise when reducing current;
🔹 Robust, simple integration: Stable with or without output capacitor; reverse-voltage protected; no startup delay or warm-up time needed.
Its SOT-23-8 (ARJZ) package (2.9 mm × 1.6 mm) offers best-in-class power density for 5 V precision references — supporting placement directly adjacent to high-resolution ADCs (e.g., AD7606C-18, LTC1867L) or analog front-ends on dense PCBs, with minimal thermal coupling and trace inductance.
Key Features
✅ Precision Performance & Stability:
• Output voltage: 5.0 V (fixed), ±0.1% max initial accuracy;
• Temperature coefficient: 3 ppm/°C (max), 1.5 ppm/°C (typ.);
• Long-term stability: 15 ppm/√kHr (typ.), < 50 ppm over 1,000 hours;
• Output noise: 12 µVP-P (0.1–10 Hz), 4.5 µVRMS (10 Hz–10 kHz).
✅ Low Power & Wide Supply Range:
• Quiescent current: 115 µA (typ.), 140 µA (max);
• Supply voltage: 5.3 V to 15 V, with reverse-voltage protection up to –15 V;
• Load current: ±10 mA (source/sink), with < 10 ppm/mA load regulation.
✅ Robust Operation & Protection:
• Thermal shutdown: activates at >150°C (hysteresis: 20°C);
• Reverse-voltage protection: survives –15 V on VOUT;
• ESD rating: > 2.5 kV HBM on all pins.
✅ Compact SOT-23-8 (ARJZ) Package & Industrial Qualification:
• 8-Lead SOT-23 (2.9 mm × 1.6 mm) with exposed pad (EP);
• RoHS-compliant, halogen-free, and qualified for –40°C to +125°C junction;
• JEDEC J-STD-020 moisture sensitivity level (MSL) 3 — standard reflow compatible.
✅ Ease of Use & Flexibility:
• Stable with 0 µF to 10 µF output capacitance — no phase-margin concerns;
• No external components required for basic operation;
• Optional output capacitor (1 µF X5R ceramic) reduces noise by ～25%.
Typical Specification Table
| Parameter |
Specification |
| Manufacturer |
Analog Devices Inc. (ADI) |
| Product Series |
ADR34xx Family (Precision Low-Power References) |
| Model |
ADR3450ARJZ-R7 |
| Function |
Fixed 5.0 V Voltage Reference |
| Output Voltage |
5.0 V (±0.1% max initial accuracy) |
| Tempco (max) |
3 ppm/°C |
| Output Noise (0.1–10 Hz) |
12 µVP-P |
| Output Noise (10 Hz–10 kHz) |
4.5 µVRMS |
| Quiescent Current |
115 µA (typ.), 140 µA (max) |
| Supply Voltage Range |
5.3 V to 15 V |
| Load Regulation |
< 10 ppm/mA |
| Output Current Capability |
±10 mA |
| Operating Junction Temp. |
–40°C to +125°C |
| Package |
8-Lead SOT-23 (2.9 mm × 1.6 mm) with Exposed Pad (ARJZ) |
| RoHS / Green |
Yes (Pb-free, Halogen-free) |
| Packaging |
7-inch Reel, 3,000 units (R7) |
Typical Applications
🔹 High-Resolution Data Acquisition: Reference for 16–24-bit SAR and sigma-delta ADCs requiring 5 V reference inputs (e.g., AD7606C-18, LTC1867L, MAX11198) — leveraging ultra-low noise and 3 ppm/°C drift to achieve true 18+ ENOB across temperature.
🔹 Legacy & Industrial Instrumentation: PLC analog modules, programmable logic controllers, and benchtop DMMs with 5 V reference architecture — replacing aging discrete or less-accurate references.
🔹 Op-Amp Precision Circuits: Gain-setting reference for instrumentation amplifiers (e.g., AD8421), voltage-controlled current sources, and precision voltage dividers — using high drive capability and low drift.
🔹 Ratiometric Sensor Excitation: Providing stable 5 V excitation for strain gauges, load cells, and pressure transducers in bridge configurations — where reference drift directly impacts measurement accuracy.
🔹 Mixed-Signal SoC Interfaces: Supplying clean 5 V reference to FPGA ADC blocks, microcontroller internal ADCs, or external DACs interfacing with 5 V logic domains.
🔹 Energy Metering & Smart Grid: Class 0.1/0.2 electricity meters (IEC 62053) with 5 V reference rails — meeting stringent accuracy requirements over –25°C to +70°C operating range.
Development & Design Notes
🔧 PCB Layout Best Practices:
- Place the ADR3450 as close as possible to the ADC/DAC reference pin — keep trace length < 5 mm and avoid vias; use ground guard ring around reference traces to reduce pickup.
- Connect the exposed pad (EP) to a solid analog ground plane via ≥ 4 thermal vias (0.25 mm) — improves thermal stability and reduces noise coupling.
- Avoid routing noisy digital signals (e.g., clocks, SCLK) near the reference path — maintain ≥ 3 mm clearance or use ground planes between layers.
🔧 Decoupling & Noise Reduction:
- Add a 1 µF X5R ceramic capacitor (0603) directly between VOUT and GND, within 1 mm of the pins — reduces broadband noise by ～25%.
- For ultimate low-frequency noise (e.g., metrology), add a parallel 10 µF tantalum capacitor — further suppresses 0.1–10 Hz ripple.
- Use separate 10 µF + 100 nF decoupling on the supply (VDD) — ensures clean bias for internal Zener core.
🔧 Thermal Management & Drift Optimization:
- Mount away from heat sources (e.g., power regulators, processors) — its 3 ppm/°C drift means 1°C self-heating = 15 nV error, but cumulative drift matters more over wide ambient swings.
- For best long-term stability, operate at moderate supply voltage (e.g., 7 V instead of 15 V) — reduces self-heating and stress on Zener junction.
🔧 Calibration & Accuracy Optimization:
- For metrology applications, perform one-time factory calibration of tempco using ADI’s published typical drift curve — enables software compensation to < 0.5 ppm/°C effective drift.
- To minimize thermal EMFs, use copper-only PCB traces (no solder mask over reference path) and avoid dissimilar metals (e.g., gold-plated connectors) in the reference path.
🔧 Reliability & Functional Safety:
- FIT rate = 14 failures per billion hours, among the lowest for precision references — suitable for 20+ year deployments in infrastructure.
- For IEC 61508 SIL-2 compliance: combine periodic self-test (e.g., measure VOUT vs. known master reference every 24 h) with watchdog-timed readback in host firmware.
