My Inquiry
My Account
Microchip Technology 1N4746CP/TR8
- Part No.:
- 1N4746CP/TR8
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
1N4746CP/TR8.pdf
- Description:
- DIODE ZENER 18V 1W DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:2,412
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1N4746CP/TR8 from Microsemi is a 1 W, 18 V ±5% Zener diode in DO-41 plastic package, rated for 14 mA test current, 20 Ω dynamic impedance at IZT, and 0.25 mA maximum reverse leakage at 13.7 V. It delivers stable voltage regulation in power supply reference and overvoltage protection circuits across -65°C to +150°C.
For engineers reviewing the 1N4746CP/TR8 datasheet, 1N4746CP/TR8 pinout, 1N4746CP/TR8 application, or 1N4746CP/TR8 equivalent, key selection factors include its 18 V nominal Zener voltage, 1 W steady-state dissipation at TL < 105°C, 45°C/W junction-to-lead thermal resistance, RoHS-compliant "e3" plating, and tape-and-reel packaging (TR8).
Technical Context
This axial-leaded silicon Zener operates in reverse breakdown to maintain a stable 18 V reference across a wide current range (5–250 mA), with sharp knee characteristics verified by dual-point Zener impedance measurement per MicroNote 202. Its DO-41 package provides moisture sensitivity Level 1 per J-STD-020B and supports lead-free soldering at 260°C for 10 s.
The device exhibits a positive temperature coefficient above ~5 V, with typical TC of +3.5 mV/°C near 18 V, enabling predictable drift compensation in precision references. It is nonsensitive to ESD per MIL-STD-750 Method 1020 and features tin-lead or matte-tin terminations solderable per MIL-STD-750 Method 2026.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18 V ±5% at IZT = 14 mA - defines nominal regulation point with tight tolerance for reference stability |
| Power Dissipation | 1.0 W at TL < 105°C (3/8″ lead length) - sets maximum continuous thermal load without derating |
| Dynamic Impedance (ZZT) | 20 Ω at IZT = 14 mA - indicates low AC impedance for minimal output voltage variation under ripple |
| Reverse Leakage (IR) | 0.25 μA max at VR = 13.7 V - ensures minimal standby current in high-impedance bias networks |
| Thermal Resistance (RθJL) | 45 °C/W junction-to-lead - enables accurate thermal design when leads serve as primary heat path |
| Forward Voltage | 1.2 V max at IF = 200 mA - defines conduction loss if used in forward-biased clamp or series configuration |
| Surge Current (ISM) | 250 mA peak (½-sine, 1/120 s) - specifies transient overvoltage handling capability without degradation |
Pinout & Package
DO-41 (DO-204AL) plastic axial-leaded package with cathode band marking; void-free UL94V-0 epoxy body, 0.7 g weight, and tin-lead or RoHS-compliant matte-tin plating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Non-banded end | Connected to circuit ground or lower potential node during Zener operation |
| Cathode | Banded end | Connected to regulated voltage node; must be held positive relative to anode for breakdown conduction |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered 1N47xxAP series | Ensures cross-manufacturer compatibility and standardized test conditions per industry baseline |
| Moisture Sensitivity Level 1 | Eliminates dry-pack requirement and floor-life constraints for SMT-compatible handling |
| RoHS-compliant "e3" suffix | Confirms lead-free termination meeting EU Directive 2011/65/EU and JEDEC J-STD-609A Class 3 |
| Tape-and-reel packaging (TR8) | Enables automated pick-and-place assembly with EIA-296 standard carrier tape and 8 mm pocket pitch |
| Nonsensitive to ESD | Withstands >4 kV HBM per MIL-STD-750 Method 1020 without parameter shift or failure |
Applications
| Power Supply Reference | Overvoltage Protection |
|---|---|
Use Scenario: Stabilizing feedback voltage in linear regulator ICs or discrete transistor-based regulators. IC Role / Device Role / Timing Role: Zener diode acting as precision shunt reference to set output voltage via resistor divider. Use Value: Delivers 18 V reference with ±5% tolerance and 20 Ω dynamic impedance, minimizing load-regulation error in 12–24 V systems. | Use Scenario: Clamping transient spikes on DC bus lines in industrial motor drives or PLC I/O modules. IC Role / Device Role / Timing Role: Shunt protector diverting excess energy to ground when line voltage exceeds 18 V threshold. Use Value: Handles 250 mA surge current (½-sine, 1/120 s) without degradation, protecting downstream MOSFETs or op-amps. |
| Voltage Monitor Threshold | Signal-Level Translation |
Use Scenario: Detecting undervoltage or overvoltage conditions in battery-powered instrumentation. IC Role / Device Role / Timing Role: Zener-based comparator input threshold generator referenced to system rail. Use Value: Provides stable 13.7 V test voltage (VR) with only 0.25 μA leakage, preserving battery life in always-on monitoring circuits. | Use Scenario: Level-shifting logic signals between 3.3 V and 5 V domains using passive Zener clamping. IC Role / Device Role / Timing Role: Bidirectional voltage limiter restricting signal swing to 18 V peak while passing low-voltage transitions. Use Value: Maintains 1.2 V forward drop and sharp 18 V reverse knee, enabling clean digital edge preservation with minimal distortion. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4746A | No "P" suffix (glass DO-35 body); higher RθJA (105°C/W vs. 45°C/W); no TR8 tape option | Less suitable for high-power-density PCBs requiring efficient lead-based heat sinking | Select 1N4746CP/TR8 for plastic DO-41 mechanical robustness, lower thermal resistance, and automated assembly support |
| MMSZ4708T1G | Surface-mount SOD-123 package; 18 V ±5%; 500 mW rating; 30 Ω ZZT; RoHS-compliant | Lower power handling and higher dynamic impedance limit use in high-current reference paths | Choose MMSZ4708T1G only when board space constraints prohibit axial-leaded components and 500 mW suffices |
Compared with 1N4746A and MMSZ4708T1G, the 1N4746CP/TR8 offers superior thermal performance (45°C/W vs. 105°C/W or unlisted), full 1 W dissipation headroom, and factory-verified tape-and-reel readiness-making it optimal for industrial power supplies requiring long-term reliability and automated manufacturing.
Availability
1N4746CP/TR8 is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, and test equipment requiring stable component supply with traceable RoHS compliance and consistent DO-41 mechanical form factor.
Supply support for 1N4746CP/TR8 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 timing solutions for aerospace, defense, and industrial markets.
The 1N47xxAP series was designed specifically for ruggedized voltage regulation in harsh-environment power systems where long-term parametric stability, ESD immunity, and moisture resilience are critical.
FAQ
What is the Zener voltage tolerance of the 1N4746CP/TR8?
The 1N4746CP/TR8 has a nominal Zener voltage of 18 V with a ±5% tolerance, as indicated by the "A" suffix in its JEDEC designation. This tolerance is guaranteed at IZT = 14 mA and TL = 25°C, and applies across the full operating temperature range of -65°C to +150°C. The 1N4746CP/TR8 meets JEDEC registration requirements for the 1N47xxA family.
Does the 1N4746CP/TR8 support lead-free assembly processes?
Yes, the 1N4746CP/TR8 carries the "e3" suffix, confirming RoHS-compliant matte-tin plating that supports lead-free reflow soldering at 260°C for up to 10 seconds. Its DO-41 package is qualified per J-STD-020B Level 1 moisture sensitivity, eliminating dry-pack requirements and enabling direct placement into automated assembly lines without baking.
What is the maximum steady-state power dissipation for the 1N4746CP/TR8?
The 1N4746CP/TR8 is rated for 1.0 W steady-state power dissipation when lead temperature (TL) is maintained below 105°C at a 3/8″ (10 mm) distance from the body. On FR4 PCBs with 1 oz copper, this corresponds to ambient temperatures below 45°C using specified 4 mm² copper pads and 1 mm × 25 mm traces. Derating curves are provided in Figure 1 of the Microsemi datasheet for 1N4746CP/TR8.
How is polarity marked on the 1N4746CP/TR8?
The 1N4746CP/TR8 uses a cathode band (typically white or black) to identify the cathode terminal. During Zener regulation, the banded end must be held positive relative to the non-banded (anode) end. This marking is laser-etched or molded into the DO-41 epoxy body and aligns with JEDEC DO-41 mechanical standards. Polarity verification is critical to avoid forward conduction instead of regulation.
Is the 1N4746CP/TR8 suitable for surge protection applications?
Yes, the 1N4746CP/TR8 is rated for 250 mA peak reverse surge current (ISM) using a ½-sine wave pulse of 1/120 second duration at 25°C ambient. This capability enables reliable clamping of transient overvoltages in DC power rails, such as those induced by inductive switching or EFT events. Its 1 W power rating and 45°C/W thermal resistance support repeated surge events without parameter shift when properly heatsinked via leads.
1N4746CP/TR8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- ±2%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 20 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 13.7 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 200 mA
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AL (DO-41)
1N4746CP/TR8 FAQ
1.How can I place an order for 1N4746CP/TR8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N4746CP/TR8 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 1N4746CP/TR8 reliable?
The price and inventory of 1N4746CP/TR8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N4746CP/TR8 is usually 5 days.
3.What payment methods are accepted for 1N4746CP/TR8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N4746CP/TR8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N4746CP/TR8?
1N4746CP/TR8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N4746CP/TR8 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 1N4746CP/TR8?
For technical support, including 1N4746CP/TR8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N4746CP/TR8 requirements.
6.How does Aetrix verify that 1N4746CP/TR8 is sourced from the original manufacturer or authorized distributors?
All 1N4746CP/TR8 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 1N4746CP/TR8 meets industry standards.
7.What is the process for return or replacement of 1N4746CP/TR8?
All 1N4746CP/TR8 units undergo pre-shipment inspection (PSI). If there is an issue with 1N4746CP/TR8, 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 1N4746CP/TR8 part is unused and in its original packaging.
Return procedure for 1N4746CP/TR8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N4746CP/TR8 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…
