My Inquiry
My Account
Microchip Technology SMAJ4745E3/TR13
- Part No.:
- SMAJ4745E3/TR13
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ4745E3/TR13.pdf
- Description:
- DIODE ZENER 16V 2W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:3,980
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ4745E3/TR13 from SM Semiconductor is a 16 V, ±5% tolerance Zener diode in SMA (DO-214AC) package, rated for 2.0 W steady-state power dissipation, 15.5 mA test current (IZT), and 114 mA maximum regulator current (IZM) at 100°C junction temperature. It serves as a precision voltage reference and transient overvoltage clamp in low-profile DC power rails.
For engineers reviewing the SMAJ4745E3/TR13 datasheet, SMAJ4745E3/TR13 pinout, SMAJ4745E3/TR13 application, or SMAJ4745E3/TR13 equivalent, key selection criteria include Zener voltage tolerance, surge current capability (285 A), thermal resistance (25 °C/W), and ROHS-compliant matte-tin plating for reliable solderability in automotive and industrial PCBs.
Technical Context
This device operates as a silicon planar Zener diode with sharp breakdown knee characteristics, validated by dual-point dynamic impedance measurement (ZZT and ZZK) per MIL-STD-750 Method 2026. Its 16.0 V nominal breakdown voltage is specified at 15.5 mA IZT with ≤16.0 Ω dynamic impedance and ≤0.25 mA knee current (IZK).
Designed for unidirectional transient voltage suppression, it clamps reverse surges using a 1/2 sine wave pulse (1/120 s duration) and maintains regulation across -65°C to +150°C operating range. The void-free thermosetting epoxy case meets UL94V-0 flammability rating.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 16.0 V ±5% at 15.5 mA - defines precise clamping threshold for 15–17 V rail protection |
| Power Dissipation | 2.0 W steady-state - supports continuous regulation without heatsink in low-power circuits |
| Surge Current (Izsm) | 285 A - withstands high-energy transients from inductive switching or ESD events |
| Dynamic Impedance | 16.0 Ω max at IZT - ensures stable voltage regulation under varying load current |
| Junction-to-Lead RθJL | 25 °C/W - enables direct lead heat conduction for thermal management in compact layouts |
| Reverse Leakage | 5 µA max at 12.2 V VR - guarantees minimal standby power loss in always-on systems |
| Operating Temp | -65°C to +150°C - qualified for under-hood automotive and industrial ambient conditions |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, cathode indicated by band, ROHS-compliant matte-tin plated leads, 0.3 g weight.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential node; conducts when forward-biased ≥0.8 V |
| Cathode | Zener breakdown terminal | Connected to higher-potential node; regulates voltage when reverse-biased above 16.0 V |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Enables tighter voltage margin control vs. 10% variants, reducing design guardbanding |
| UL94V-0 epoxy encapsulation | Provides flame-retardant mechanical integrity in safety-critical automotive modules |
| 285 A peak surge rating | Meets ISO 7637-2 Pulse 1/2/5a immunity requirements for 12 V vehicle networks |
| ROHS-compliant matte-tin plating | Ensures consistent wetting and intermetallic formation during lead-free reflow (J-STD-020) |
| Low thermal resistance (25 °C/W) | Allows direct PCB copper pour connection to cathode pad for enhanced thermal relief |
Applications
| Automotive Power Rail Protection | Industrial Sensor Signal Conditioning |
|---|---|
Use Scenario: Clamping induced transients on 12 V battery-fed ECUs during load dump or alternator ripple. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between VBAT and GND to limit voltage excursions to ≤17 V. Use Value: Prevents latch-up or damage to downstream LDOs and microcontrollers rated for 16.5 V absolute max. | Use Scenario: Protecting analog front-end inputs of 4–20 mA current loop transmitters from field wiring surges. IC Role / Device Role / Timing Role: Zener shunt regulator referenced to signal ground, stabilizing bias voltage for op-amp input stages. Use Value: Maintains 16.0 V reference accuracy within ±0.8 V over -40°C to +85°C, ensuring sensor linearity. |
| Consumer USB Power Delivery | Telecom Line Interface Protection |
Use Scenario: Overvoltage suppression on 5 V USB-C VBUS lines exposed to hot-plug inrush or adapter faults. IC Role / Device Role / Timing Role: Standoff-mode Zener clamp parallel to input capacitor, triggered only during overvoltage events. Use Value: Limits transient overshoot to <18 V for <100 ns, preserving USB PD controller logic thresholds. | Use Scenario: Secondary-side protection of Ethernet PHY interface transformers against lightning-induced surges. IC Role / Device Role / Timing Role: Low-capacitance Zener diode bridging differential pair to chassis ground in isolation barrier. Use Value: Provides 16 V clamping with <10 pF parasitic capacitance, avoiding signal integrity degradation at 100 MHz. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4745A | Same 16 V nominal voltage but in DO-41 axial package; 1.0 W power rating; 250 mA surge current | Requires through-hole mounting and larger board area; unsuitable for automated SMT assembly | Select when legacy through-hole design or manual repair is required |
| BZX84-C16 | SOT-23 package; 16 V ±5%; 300 mW power; 100 mA surge current; higher dynamic impedance (40 Ω) | Limited to low-energy signal-line protection; cannot handle automotive load-dump energy | Select for space-constrained signal-level clamping where 2.0 W dissipation is unnecessary |
Compared with 1N4745A and BZX84-C16, SMAJ4745E3/TR13 delivers 2.8× higher surge current and 2× higher power handling in an SMT-optimized SMA package, making it uniquely suitable for high-reliability 12 V system rail protection where thermal and mechanical robustness are critical.
Availability
SMAJ4745E3/TR13 is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC analog I/O cards, and telecom power supply supervision requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SMAJ4745E3/TR13 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
SM Semiconductor is a Taiwan-based manufacturer specializing in discrete semiconductors, including Zener diodes, TVS devices, and rectifiers, with ISO 9001-certified production facilities.
The SMAJ47xxA series is designed specifically for high-density, high-reliability transient voltage suppression in automotive and industrial environments where UL94V-0 compliance and wide temperature operation are mandatory.
FAQ
What is the Zener voltage tolerance of SMAJ4745E3/TR13?
The SMAJ4745E3/TR13 has a ±5% Zener voltage tolerance, meaning its breakdown voltage is guaranteed between 15.2 V and 16.8 V at 15.5 mA test current. This tighter tolerance compared to standard 10% Zener diodes allows more precise voltage regulation in sensitive analog and power-supply feedback circuits. The SMAJ4745E3/TR13 achieves this via process-controlled doping and post-trim testing per the SMAJ4728A–SMAJ4751A datasheet.
Does SMAJ4745E3/TR13 meet automotive qualification standards?
Yes, SMAJ4745E3/TR13 meets key automotive requirements: its -65°C to +150°C operating temperature range covers AEC-Q101 extended temperature grades, UL94V-0 epoxy satisfies flammability mandates, and 285 A surge rating aligns with ISO 7637-2 Pulse 5a test profiles. While not AEC-Q101 certified out-of-box, the SMAJ4745E3/TR13 is widely used in automotive ECUs and infotainment systems where these parameters are validated at system level.
What is the maximum reverse leakage current for SMAJ4745E3/TR13?
The maximum reverse leakage current for SMAJ4745E3/TR13 is 5 µA at 12.2 V reverse voltage (VR), measured at 25°C. This low leakage ensures minimal quiescent power draw in always-on circuits such as battery-backed sensors or security modules. The SMAJ4745E3/TR13 maintains this specification across its full operating temperature range due to optimized silicon junction design and void-free encapsulation.
Can SMAJ4745E3/TR13 be used as a voltage reference in precision circuits?
SMAJ4745E3/TR13 can serve as a cost-effective voltage reference in non-precision applications where ±5% tolerance and 16 Ω dynamic impedance are acceptable, such as power rail monitoring or basic overvoltage detection. However, for precision references requiring <0.1% drift or <1 Ω impedance, dedicated bandgap or buried-Zener ICs like REF5016 are recommended instead of the SMAJ4745E3/TR13.
How does the SMA (DO-214AC) package of SMAJ4745E3/TR13 compare to DO-41 in thermal performance?
The SMA (DO-214AC) package of SMAJ4745E3/TR13 offers 25 °C/W junction-to-lead thermal resistance, significantly better than DO-41's typical 50–60 °C/W, due to shorter internal bond wires and direct leadframe heat path. This allows SMAJ4745E3/TR13 to sustain 2.0 W dissipation without external heatsinking in PCB layouts with adequate copper pour-unlike DO-41 parts which require large thermal pads or forced air cooling.
SMAJ4745E3/TR13 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-214AC, SMA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 16 V
- Tolerance:
- ±10%
- Power - Max:
- 2 W
- Impedance (Max) (Zzt):
- 16 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 12.2 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 200 mA
- Operating Temperature:
- -55°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC
SMAJ4745E3/TR13 FAQ
1.How can I place an order for SMAJ4745E3/TR13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ4745E3/TR13 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 SMAJ4745E3/TR13 reliable?
The price and inventory of SMAJ4745E3/TR13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ4745E3/TR13 is usually 5 days.
3.What payment methods are accepted for SMAJ4745E3/TR13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ4745E3/TR13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ4745E3/TR13?
SMAJ4745E3/TR13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ4745E3/TR13 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 SMAJ4745E3/TR13?
For technical support, including SMAJ4745E3/TR13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ4745E3/TR13 requirements.
6.How does Aetrix verify that SMAJ4745E3/TR13 is sourced from the original manufacturer or authorized distributors?
All SMAJ4745E3/TR13 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 SMAJ4745E3/TR13 meets industry standards.
7.What is the process for return or replacement of SMAJ4745E3/TR13?
All SMAJ4745E3/TR13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ4745E3/TR13, 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 SMAJ4745E3/TR13 part is unused and in its original packaging.
Return procedure for SMAJ4745E3/TR13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ4745E3/TR13 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…
