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Microchip Technology CDLL821A/TR
- Part No.:
- CDLL821A/TR
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-213AA
- Datasheet:
-
CDLL821A/TR.pdf
- Description:
- DIODE ZENER 6.2V 500MW DO213AA
- Quantity:
- Payment:
- Shipping:
Inventory:7,923
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Product details
Overview
CDLL821A/TR from Central Semiconductor (CDI) is a temperature-compensated, hermetically sealed MELF-packaged Zener diode with nominal zener voltage 5.9–6.5 V, 10 Ω zener impedance at 7.5 mA test current, ±0.01 %/°C temperature coefficient, and 500 mW power rating at +50°C. It serves as a precision voltage reference in analog power supply feedback loops and sensor biasing circuits.
For engineers reviewing the CDLL821A/TR datasheet, CDLL821A/TR pinout, CDLL821A/TR application, or CDLL821A/TR equivalent, key selection criteria include its low-impedance 10 Ω zener dynamic resistance, tight ±0.01 %/°C tempco over –55°C to +100°C, DO-213AA (SOD-80/LL34) MELF package compatibility, and 2 µA reverse leakage at 3 V.
Technical Context
This device uses metallurgically bonded, double-plug construction to achieve stable zener voltage regulation across wide temperature extremes. Its hermetic glass MELF package enables operation from –65°C to +175°C ambient, with power derating starting above +50°C at 4 mW/°C.
The CDLL821A/TR exhibits a measured zener impedance of 10 Ω at IZT = 7.5 mA, derived using 10% 60 Hz AC superimposed on DC bias per JEDEC 5. Its temperature coefficient stability is verified per JEDEC standard No. 5, with maximum voltage drift ≤96 mV over –55°C to +100°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage Range | 5.9–6.5 V at 7.5 mA - defines usable regulation band for precision reference design |
| Zener Impedance | 10 Ω at IZT = 7.5 mA - ensures minimal output voltage variation under load transients |
| Temperature Coefficient | ±0.01 %/°C - guarantees <±0.65 mV/°C drift in 6.5 V nominal operation |
| Max Voltage Drift | ≤96 mV over –55°C to +100°C - meets JEDEC 5 stability requirement for critical references |
| Power Dissipation | 500 mW @ +50°C - supports continuous operation in compact thermal environments |
| Reverse Leakage | 2 µA @ 3 V, 25°C - minimizes quiescent current draw in high-impedance bias networks |
Pinout & Package
Package: DO-213AA (MELF, SOD-80, LL34), hermetically sealed glass case with tin/lead lead finish. Cathode identified by band; operated with banded end positive.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference node | Connected to circuit ground or lower-potential rail in shunt regulator configuration |
| Cathode (banded end) | Zener breakdown terminal / regulated output node | Provides stable 5.9–6.5 V reference when reverse-biased; must be held at higher potential than anode |
Key Features
| Feature | Design Value |
|---|---|
| Hermetic MELF packaging | Enables reliable operation from –65°C to +175°C without moisture-induced parameter shift |
| Metallurgically bonded double-plug construction | Reduces long-term voltage drift and improves thermal transient response vs. single-junction Zeners |
| Low 10 Ω zener impedance | Delivers <10 mV output change for 100 mA load step in 1 kΩ series resistor configurations |
| ±0.01 %/°C tempco | Supports sub-10 ppm/°C system-level reference stability when combined with matched passive components |
Applications
| Industrial Sensor Signal Conditioning | Medical Instrumentation Reference |
|---|---|
Use Scenario: Biasing bridge-based pressure sensors in factory automation transmitters operating from –40°C to +85°C ambient. IC Role / Device Role / Timing Role: Provides stable 6.2 V reference for ADC driver op-amps and excitation circuitry. Use Value: 10 Ω zener impedance maintains <0.5 LSB error contribution under 10 mA sensor excitation load variation. | Use Scenario: Precision voltage reference in portable ECG front-end analog signal chain. IC Role / Device Role / Timing Role: Sets gain and offset calibration points for low-noise instrumentation amplifiers. Use Value: ±0.01 %/°C tempco ensures <±2 µV/°C drift in 6.5 V nominal operation, meeting IEC 60601-2-27 linearity requirements. |
| Avionics Power Supply Monitoring | Test & Measurement Equipment Calibration |
Use Scenario: Overvoltage detection threshold in MIL-STD-704 compliant 28 V DC aircraft power systems. IC Role / Device Role / Timing Role: Shunt regulator element in comparator input stage defining trip point. Use Value: Hermetic DO-213AA package withstands thermal cycling and humidity exposure per DO-160 Section 16. | Use Scenario: Internal reference source in handheld multimeters requiring traceable 6.2 V calibration point. IC Role / Device Role / Timing Role: Primary voltage standard for auto-ranging DAC calibration routines. Use Value: ≤96 mV total drift over –55°C to +100°C enables one-time factory calibration valid across full operational range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CDLL821 | Zener impedance 15 Ω (vs. 10 Ω for CDLL821A/TR); same voltage range and tempco | Suitable where tighter impedance not required; higher ZZT increases load regulation error | Select CDLL821A/TR when <10 mV load regulation error is required at 7.5 mA |
| 1N821UR-1 | MIL-PRF-19500/159 qualified; identical electrical specs but with JAN/JANTXV screening levels | Required for defense/aerospace programs mandating military-grade reliability testing | Choose 1N821UR-1 only when MIL-spec qualification and extended screening are contractually required |
Compared with CDLL821 and 1N821UR-1, the CDLL821A/TR delivers optimal balance of low-impedance regulation and commercial-grade cost, making it preferred for industrial and medical instruments where MIL screening is unnecessary but sub-10 Ω dynamic resistance is critical.
Availability
CDLL821A/TR is available at Aetrix Electronics and suitable for industrial sensor conditioning, medical instrumentation reference, avionics monitoring, and test equipment calibration requiring stable component supply and consistent parametric performance across production lots.
Supply support for CDLL821A/TR 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
Central Semiconductor (CDI) is a U.S.-based manufacturer specializing in discrete semiconductors, including Zener, Schottky, and switching diodes, with emphasis on high-reliability and temperature-stable devices.
The CDLL821A/TR belongs to CDI's temperature-compensated MELF Zener family, designed specifically for precision voltage reference applications demanding low drift, hermetic reliability, and stable regulation across extreme industrial and aerospace temperature ranges.
FAQ
What is the exact zener voltage tolerance of CDLL821A/TR at 7.5 mA test current?
The CDLL821A/TR has a specified zener voltage range of 5.9 V to 6.5 V at IZT = 7.5 mA, representing a ±5.0% tolerance around the nominal 6.2 V center point. This range is guaranteed per datasheet Table 1 and applies across the full operating temperature range of –55°C to +100°C.
Does CDLL821A/TR require heatsinking in standard PCB layouts?
No, CDLL821A/TR does not require external heatsinking under typical conditions. Its 500 mW power rating at +50°C and 4 mW/°C derating allow safe operation up to 175°C junction temperature with natural convection in standard FR-4 layouts. Thermal design should verify board copper area and ambient airflow per Figure 2 derating curve.
How does the DO-213AA package of CDLL821A/TR affect reflow soldering profiles?
The DO-213AA (MELF) glass package of CDLL821A/TR requires strict adherence to peak reflow temperatures ≤260°C for ≤10 seconds, per CDI's recommended profile. Exceeding this risks glass-to-metal seal fracture. The axial coefficient of expansion (+6 ppm/°C) also necessitates matching substrate CTE to avoid mechanical stress during thermal cycling.
Is CDLL821A/TR compatible with lead-free assembly processes?
CDLL821A/TR features tin/lead lead finish and is not rated for lead-free reflow. For RoHS-compliant designs, Central Semiconductor offers alternate part numbers with matte tin terminations; CDLL821A/TR itself must be processed using SnPb-compatible profiles and should not be subjected to >220°C peak temperatures typical of lead-free soldering.
Can CDLL821A/TR replace CDLL821 in existing designs without layout changes?
Yes, CDLL821A/TR is a direct drop-in replacement for CDLL821 in the same DO-213AA package, sharing identical pinout, dimensions, and voltage range. The only functional difference is reduced zener impedance (10 Ω vs. 15 Ω), which improves load regulation without requiring PCB or schematic modifications.
CDLL821A/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-213AA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 6.2 V
- Tolerance:
- ±4.83%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 10 Ohms
- Current - Reverse Leakage @ Vr:
- 2 µA @ 3 V
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- -65°C ~ 175°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-213AA
CDLL821A/TR FAQ
1.How can I place an order for CDLL821A/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for CDLL821A/TR 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 CDLL821A/TR reliable?
The price and inventory of CDLL821A/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CDLL821A/TR is usually 5 days.
3.What payment methods are accepted for CDLL821A/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CDLL821A/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CDLL821A/TR?
CDLL821A/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CDLL821A/TR 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 CDLL821A/TR?
For technical support, including CDLL821A/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CDLL821A/TR requirements.
6.How does Aetrix verify that CDLL821A/TR is sourced from the original manufacturer or authorized distributors?
All CDLL821A/TR 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 CDLL821A/TR meets industry standards.
7.What is the process for return or replacement of CDLL821A/TR?
All CDLL821A/TR units undergo pre-shipment inspection (PSI). If there is an issue with CDLL821A/TR, 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 CDLL821A/TR part is unused and in its original packaging.
Return procedure for CDLL821A/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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