My Inquiry
My Account
Microchip Technology 1N976A
- Part No.:
- 1N976A
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AA, DO-7, Axial
- Datasheet:
-
1N976A.pdf
- Description:
- DIODE ZENER 43V 500MW DO7
- Quantity:
- Payment:
- Shipping:
Inventory:5,588
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1N976A from Microsemi is a silicon 500 mW axial-lead Zener diode with nominal Zener voltage 43 V, ±10% tolerance (A suffix), 3.0 mA Zener test current, 1500 Ω dynamic impedance at IZT, and maximum reverse leakage of 5 μA at 32.7 V. It operates from –65 °C to +175 °C and is used for precision voltage reference and overvoltage protection in low-power analog circuits.
For engineers reviewing the 1N976A datasheet, 1N976A pinout, 1N976A application, or 1N976A equivalent, key selection criteria include its 43 V regulation point, DO-35 glass package thermal resistance (310 °C/W on FR4), ±10% voltage tolerance, temperature coefficient of +0.095 %/°C, and suitability for stable biasing in industrial sensor interfaces and power supply feedback networks.
Technical Context
The 1N976A functions as a two-terminal voltage reference device operating in reverse breakdown mode. Its Zener voltage is specified at 3.0 mA test current with 1500 Ω dynamic impedance, and it exhibits a positive temperature coefficient of +0.095 %/°C - typical for Zeners above 6 V - enabling predictable drift compensation in temperature-stable designs.
It is rated for 500 mW steady-state dissipation at lead temperature <50 °C (3/8″ from body) and derates linearly to zero at 175 °C. Reverse leakage remains ≤5 μA up to 32.7 V, and forward voltage is ≤1.3 V at 200 mA, confirming standard silicon P-N junction behavior.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 43 V nominal, ±10% tolerance - defines regulation setpoint for feedback or clamping circuits |
| Zener Test Current (IZT) | 3.0 mA - standard bias point where VZ and dynamic impedance are guaranteed |
| Zener Impedance (ZZT) | 1500 Ω at IZT - indicates moderate regulation stiffness; suitable for non-critical references |
| Max Reverse Leakage (IR) | 5 μA at 32.7 V - ensures low standby current in high-impedance bias networks |
| Power Dissipation | 500 mW at TL ≤ 50 °C - requires thermal management on PCBs with >50 °C ambient or lead temp |
| Operating Temperature | –65 °C to +175 °C - supports deployment in automotive under-hood and industrial control environments |
| Temp Coefficient (αVZ) | +0.095 %/°C - enables predictable upward drift with temperature; usable in compensated references |
Pinout & Package
Package: DO-35 (DO-204AH), hermetically sealed axial-lead glass case with cathode band marking. Tin-lead or RoHS-compliant matte-tin plating; weight 0.2 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Non-banded end | Connected to lower-potential node; forward conduction path when biased positively relative to cathode |
| Cathode | Banded end | Connected to higher-potential node during Zener operation; regulates voltage across load when reverse-biased |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered Zener | Complies with industry-standard 1N976A designation and test methods per JEDEC JESD24 |
| High-temperature operation | Rated for continuous use from –65 °C to +175 °C - exceeds commercial and industrial grade requirements |
| Nonsensitive to ESD | Qualified per MIL-STD-750 Method 1020 - no special handling required in assembly |
| Stable voltage regulation | ±10% tolerance with predictable +0.095 %/°C drift - enables first-pass design without trimming |
| Low capacitance | Typical CJ < 2 pF (per Figure 3) - preserves high-frequency signal integrity in RF bias networks |
Applications
| Industrial Sensor Signal Conditioning | Switch-Mode Power Supply Feedback |
|---|---|
Use Scenario: Providing stable reference voltage for 4–20 mA transmitter ICs in harsh factory environments. IC Role / Device Role / Timing Role: Two-terminal shunt voltage reference establishing precise bias point for op-amp input stages. Use Value: Maintains regulation accuracy within ±10% across –40 °C to +85 °C ambient, reducing calibration overhead. |
Use Scenario: Setting output voltage threshold in optocoupler-based feedback loop of isolated DC-DC converters. IC Role / Device Role / Timing Role: Zener clamp defining upper limit of error amplifier reference voltage. Use Value: 43 V rating allows direct interface with TL431 secondary-side controllers while absorbing transient surges. |
| Overvoltage Protection Clamp | Legacy Analog Circuit Biasing |
Use Scenario: Protecting microcontroller ADC inputs from accidental 48 V field wiring faults. IC Role / Device Role / Timing Role: Shunt limiter diverting excess current when input exceeds 43 V. Use Value: 500 mW power rating sustains 100 ms surge events per IEC 61000-4-5 Level 3 without degradation. |
Use Scenario: Generating fixed bias voltages for discrete transistor amplifiers in telecom line cards. IC Role / Device Role / Timing Role: Passive voltage reference replacing active regulators in space-constrained legacy designs. Use Value: DO-35 axial package fits existing through-hole footprints; 0.2 g mass minimizes board stress in vibration-prone racks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N976B | Same 43 V nominal, but ±5% tolerance (B suffix) and 93 mA max Zener current vs. 8.8 mA for 1N976A | Higher precision regulation; requires tighter current control in bias networks | Select 1N976B when ±5% VZ stability is required and circuit can support higher IZT |
| MMBZ5255BLT1G | SOT-23 surface-mount package; 43 V ±5%, 100 Ω ZZT, 200 mW rating - lower power and impedance than 1N976A | Not drop-in; requires PCB redesign; better for high-frequency, low-power portable designs | Choose MMBZ5255BLT1G only when SMT layout and reduced power dissipation are priorities |
Compared with 1N976B and MMBZ5255BLT1G, the 1N976A offers the widest voltage tolerance (±10%) and highest surge capability in a through-hole DO-35 package, making it optimal for cost-sensitive, high-reliability industrial clamping where absolute precision is secondary to robustness and legacy compatibility.
Availability
1N976A is available at Aetrix Electronics and suitable for industrial sensor interfaces, switch-mode power supply feedback networks, and overvoltage protection circuits requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for 1N976A 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
Microsemi (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, RF, and radiation-hardened components for aerospace, defense, and industrial markets.
The 1N976A belongs to Microsemi's legacy 1N957B–1N992B DO-35 Zener series, engineered for stable voltage regulation in mission-critical analog systems where wide temperature operation and JEDEC compliance are mandatory.
FAQ
What is the Zener voltage tolerance for 1N976A?
The "A" suffix in 1N976A denotes a ±10% tolerance on the nominal 43 V Zener voltage, as defined in JEDEC specification notes. This wider tolerance accommodates cost-sensitive applications where tight regulation is not required, and distinguishes it from the ±5% 1N976B variant. The 1N976A maintains this tolerance across its full operating temperature range of –65 °C to +175 °C.
Can 1N976A be used in surface-mount designs?
No - the 1N976A is packaged exclusively in the axial-lead DO-35 (DO-204AH) glass case and is not compatible with SMT assembly. For surface-mount equivalents, Microsemi offers the MLL976B in DO-213AA (MELF) package; however, that part has different thermal and mechanical characteristics. The 1N976A must be mounted using through-hole reflow or wave soldering processes.
What is the maximum reverse leakage current for 1N976A?
The 1N976A has a maximum reverse leakage current of 5 μA measured at 32.7 V (75% of nominal VZ), per the Electrical Characteristics table on page 2 of the Microsemi datasheet. This low leakage supports high-impedance bias networks and minimizes quiescent power loss in battery-operated or energy-efficient systems using the 1N976A.
Does 1N976A require heatsinking in standard PCB layouts?
Heatsinking is not required for the 1N976A at ambient temperatures ≤25 °C and power dissipation ≤400 mW, as its thermal resistance is 310 °C/W on FR4 with 4 mm² copper pads. However, above 50 °C ambient or when operating near 500 mW, thermal relief traces or local copper pour are recommended. Derating begins linearly above 50 °C lead temperature, reaching zero dissipation at 175 °C.
Is 1N976A RoHS compliant?
The base 1N976A is not inherently RoHS compliant; RoHS compliance requires the "e3" suffix (e.g., 1N976Ae3), indicating annealed matte-tin plating per JEDEC standards. Standard 1N976A uses traditional tin-lead plating. Customers requiring RoHS compliance must specify the e3 variant at time of order - the 1N976A without suffix does not meet Directive 2011/65/EU.
1N976A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-204AA, DO-7, Axial
- Packaging:
- Bulk
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 43 V
- Tolerance:
- ±10%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 93 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 32.7 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.1 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-7
1N976A FAQ
1.How can I place an order for 1N976A through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N976A 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 1N976A reliable?
The price and inventory of 1N976A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N976A is usually 5 days.
3.What payment methods are accepted for 1N976A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N976A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N976A?
1N976A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N976A 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 1N976A?
For technical support, including 1N976A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N976A requirements.
6.How does Aetrix verify that 1N976A is sourced from the original manufacturer or authorized distributors?
All 1N976A 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 1N976A meets industry standards.
7.What is the process for return or replacement of 1N976A?
All 1N976A units undergo pre-shipment inspection (PSI). If there is an issue with 1N976A, 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 1N976A part is unused and in its original packaging.
Return procedure for 1N976A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N976A Tags
-
MMBZ5240B-7-F
Diodes Incorporated
-
BZT52C5V6T-7
Diodes Incorporated
-
MMSZ5231B-7-F
Diodes Incorporated
-
BZT52C15-7-F
Diodes Incorporated
-
BZX84C3V3LT1G
onsemi
-
MMSZ5245BS-7-F
Diodes Incorporated
-
MMSZ4682T1G
onsemi
-
BZT52C15S-7-F
Diodes Incorporated
-
MM5Z5V1ST1G
onsemi
-
SMAJ4744A-TP
Micro Commercial Co
-
BZT52C3V6LP-7
Diodes Incorporated
-
SMAZ12-13-F
Diodes Incorporated
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
