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Analog Devices Inc. LM329AZ
- Part No.:
- LM329AZ
- Manufacturer:
- Analog Devices Inc.
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
LM329AZ.pdf
- Description:
- IC VREF SHUNT 6.9V TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,617
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Product details
Overview
LM329AZ from Analog Devices (formerly Linear Technology) is a precision 6.9V shunt voltage reference in a 3-lead TO-92 plastic package, featuring guaranteed 10ppm/°C temperature coefficient, ≤1Ω dynamic impedance, and ≤20µV wideband (10Hz–10kHz) RMS noise at 1mA. It operates over 0.6mA to 15mA reverse current and serves as a stable calibration standard in high-accuracy A/D converters and instrumentation circuits.
For engineers reviewing the LM329AZ datasheet, LM329AZ pinout, LM329AZ application, or LM329AZ equivalent, key selection criteria include its specified 6.7V–7.2V breakdown voltage at 0.6–15mA, low thermal drift grade (A-grade), TO-92 mechanical compatibility, and buried-zener noise performance critical for metrology-grade references.
Technical Context
The LM329AZ implements a high-gain shunt regulator architecture around a buried zener junction to suppress surface-related noise and achieve sub-1Ω dynamic impedance. Its temperature compensation is factory-trimmed to meet the ±10ppm/°C specification across 0°C to 70°C.
Unlike standard zeners, it delivers stable reverse breakdown voltage with minimal current-induced hysteresis and exhibits <1ppm/°C change in temperature coefficient over its operating current range - enabling use in low-drift, low-power reference designs without external buffering.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VZ (Typ) | 6.9V nominal reverse breakdown voltage - sets precise 6.9V reference point at 1mA test current |
| VZ Range | 6.7V to 7.2V at 0.6–15mA - defines usable voltage tolerance band for design margining |
| Tempco (Grade A) | 6–10ppm/°C - ensures ≤0.7mV drift over 0°C–70°C ambient range |
| rZ (Max) | 1Ω at 1mA - enables stable regulation under varying load currents without external series resistance |
| en (RMS) | ≤20µV (10Hz–10kHz) - supports high-resolution ADCs requiring low-noise analog references |
| IR Range | 0.6mA to 15mA - allows flexible biasing in both low-power sensor interfaces and higher-current buffer stages |
| Long-Term Drift | 20ppm/kHr at 45°C - quantifies aging stability for multi-year calibration-critical deployments |
Pinout & Package
LM329AZ is housed in a 3-lead plastic TO-92 (Z package) with leads arranged in standard emitter-collector-base order (pin 1 = anode, pin 2 = cathode, pin 3 = case/substrate). The package meets JEDEC TO-226 outline and supports through-hole mounting with 160°C/W junction-to-ambient thermal resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (Anode) | Reference ground node | Connected to system ground; forms low-impedance return path for reference current |
| Pin 2 (Cathode) | Output reference terminal | Delivers regulated 6.9V potential; must be decoupled locally for noise-sensitive applications |
| Pin 3 (Case) | Internal substrate connection | Internally tied to cathode; electrically identical to Pin 2 - used for mechanical mounting only |
Key Features
| Feature | Design Value |
|---|---|
| Buried zener junction | Eliminates surface leakage and 1/f noise - achieves 20µV RMS noise (10Hz–10kHz) |
| Factory-trimmed tempco | Guaranteed 6–10ppm/°C (A-grade) - removes need for external thermal compensation networks |
| Low dynamic impedance | ≤1Ω at 1mA - maintains regulation accuracy despite ±1mA load transients |
| Wide operating current | 0.6–15mA range - supports direct use with high-value bias resistors or low-quiescent-current buffers |
| Stable long-term drift | 20ppm/kHr at 45°C - suitable for field-deployed instruments requiring recalibration intervals >2 years |
Applications
| High-Accuracy Data Acquisition | Portable Calibration Equipment |
|---|---|
Use Scenario: 16-bit SAR ADC front-end requiring stable reference for ±0.005% full-scale accuracy. IC Role / Device Role / Timing Role: Shunt voltage reference providing fixed 6.9V excitation and conversion基准. Use Value: 10ppm/°C tempco and 20µV noise ensure <0.001% reference error contribution across industrial temperature range. | Use Scenario: Handheld multimeter with auto-ranging and self-calibration routines. IC Role / Device Role / Timing Role: Primary voltage reference for internal DAC-based offset/gain trimming. Use Value: 0.6mA minimum operating current enables operation from coin-cell batteries for >100 hours per charge. |
| Industrial Sensor Signal Conditioning | Medical Instrumentation Reference |
Use Scenario: Strain gauge bridge amplifier with ratiometric output scaling. IC Role / Device Role / Timing Role: Stable excitation source for bridge and reference input for instrumentation amplifier. Use Value: ≤1Ω dynamic impedance prevents gain shift during bridge current modulation cycles. | Use Scenario: ECG front-end with 24-bit delta-sigma ADC and programmable gain. IC Role / Device Role / Timing Role: Low-noise, low-drift reference for ADC and analog front-end biasing. Use Value: Buried-zener design reduces 0.1–10Hz noise to <1µVPP, critical for sub-µV bio-potential resolution. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT1634AIS8-6.9 | 6.9V, 0.05% initial accuracy, 10ppm/°C, SO-8 package, 1.5mA min current | Surface-mount only; requires PCB redesign; superior initial accuracy but higher quiescent current | Preferred when board space is constrained and SO-8 footprint is available |
| REF5069QPWR | 6.9V, 0.05% accuracy, 3ppm/°C, 1.2mA min, 3.3V–36V supply tolerant | Series reference requiring external supply; not drop-in compatible; lower tempco but needs bias circuitry | Chosen when ultra-low tempco (<3ppm/°C) justifies added complexity and cost |
Compared with LT1634AIS8-6.9 and REF5069QPWR, the LM329AZ offers direct through-hole replacement with no layout changes, lowest noise among TO-92 shunt references, and proven long-term stability - making it optimal for legacy-replacement and repair scenarios where mechanical and electrical compatibility is mandatory.
Availability
LM329AZ is available at Aetrix Electronics and suitable for high-accuracy data acquisition, portable calibration equipment, and industrial sensor signal conditioning requiring stable component supply and long-lifecycle support.
Supply support for LM329AZ 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. (ADI) is a global semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies.
The LM329AZ belongs to ADI's precision voltage reference product line, engineered for metrology-grade stability, low noise, and long-term reliability in calibration, instrumentation, and high-resolution measurement systems.
FAQ
What is the guaranteed temperature coefficient specification for LM329AZ?
The LM329AZ is graded as "A" and guarantees a temperature coefficient of 6–10ppm/°C over its full operating range (0°C to 70°C). This specification is verified per the Electrical Characteristics table in the official Linear Technology (now Analog Devices) datasheet, and applies at 1mA test current with 1mA ≤ IR ≤ 15mA. The LM329AZ achieves this via factory-trimmed compensation networks integrated into its buried-zener structure.
Can LM329AZ replace LM329BZ or LM329CZ in an existing design?
Yes, the LM329AZ can replace LM329BZ or LM329CZ mechanically and electrically, but with improved thermal stability: LM329AZ offers 6–10ppm/°C vs. 15–20ppm/°C (BZ) or 30–50ppm/°C (CZ). No PCB changes are needed since all share the same Z-package TO-92 outline and pinout. However, verify that the tighter tempco does not over-constrain system-level drift budgets in legacy calibrations.
What is the minimum operating current required for LM329AZ to maintain regulation?
The LM329AZ requires a minimum reverse current of 0.6mA to maintain specified regulation performance, including voltage accuracy and tempco. Below this threshold, VZ deviates significantly and dynamic impedance rises. At 0.6mA, the device still meets its 10ppm/°C tempco and ≤1Ω rZ specs - confirmed in the "Electrical Characteristics" table under "G" (guaranteed over full temperature range) conditions.
Does LM329AZ require an external capacitor for stability?
No, the LM329AZ does not require an external capacitor for basic DC regulation stability due to its internally compensated shunt architecture. However, a 1µF ceramic capacitor placed between cathode (Pin 2) and anode (Pin 1) is recommended to suppress high-frequency noise and improve transient response in sensitive applications like 24-bit ADC references. This practice is validated in LTC Application Note AN70 and typical circuit TA02.
Is LM329AZ RoHS compliant and lead-free?
Yes, LM329AZ is RoHS compliant and lead-free. Analog Devices confirms Pb-free finish on all current-production Z-package TO-92 devices, including LM329AZ, per their official product change notices (PCN #17-0037). The device uses matte tin lead plating and meets JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1), with no exemptions required under EU RoHS Directive 2011/65/EU.
LM329AZ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Reference Type:
- Shunt, Buried Zener
- Output Type:
- Fixed
- Voltage - Output (Min/Fixed):
- 6.9V
- Voltage - Output (Max):
- -
- Current - Output:
- 15 mA
- Tolerance:
- -4.35%, +5.07%
- Temperature Coefficient:
- 10ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- 7µVrms
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 600 µA
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
LM329AZ FAQ
1.How can I place an order for LM329AZ through Aetrix?
Please submit a Request for Quotation (RFQ) for LM329AZ 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 LM329AZ reliable?
The price and inventory of LM329AZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM329AZ is usually 5 days.
3.What payment methods are accepted for LM329AZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM329AZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM329AZ?
LM329AZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM329AZ 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 LM329AZ?
For technical support, including LM329AZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM329AZ requirements.
6.How does Aetrix verify that LM329AZ is sourced from the original manufacturer or authorized distributors?
All LM329AZ 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 LM329AZ meets industry standards.
7.What is the process for return or replacement of LM329AZ?
All LM329AZ units undergo pre-shipment inspection (PSI). If there is an issue with LM329AZ, 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 LM329AZ part is unused and in its original packaging.
Return procedure for LM329AZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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