My Inquiry
My Account
Taiwan Semiconductor Corporation 1SMA4737
- Part No.:
- 1SMA4737
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- Single Zener Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
1SMA4737.pdf
- Description:
- DIODE ZENER 7.5V 1W DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:2,896
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1SMA4737 from Taiwan Semiconductor is a surface-mount 1 W Zener diode with nominal zener voltage 7.5 V ±5%, test current 34 mA, dynamic impedance 4 Ω at IZT, and maximum junction temperature 175 °C. It serves as a precision voltage reference and overvoltage clamp in power supply regulation and transient protection circuits.
For engineers reviewing the 1SMA4737 datasheet, 1SMA4737 pinout, 1SMA4737 application, or 1SMA4737 equivalent, key selection criteria include its DO-214AC (SMA) package, low leakage (<5 µA at 5 V), glass-passivated junction, and compliance with JESD201 Class 2 whisker resistance and J-STD-020 Level 1 moisture sensitivity.
Technical Context
The 1SMA4737 operates as a single-die, unidirectional Zener diode optimized for stable reverse-bias breakdown at 7.5 V under 34 mA test current. Its 4 Ω dynamic impedance at IZT and <5 µA leakage at 5 V support tight regulation in low-power reference and clamping roles.
Designed for surface-mount assembly on PCBs with 5 mm × 5 mm copper pads, it delivers 1 W continuous dissipation at 25 °C ambient and derates linearly to zero at 175 °C junction temperature. Non-repetitive surge capability reaches 60 W for 100 µs pulses.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 7.5 V ±5% - defines precise clamping threshold for 5 V–12 V rail protection |
| Test Current (IZT) | 34 mA - operating point where VZ and ZZT are specified and optimized |
| Zener Impedance (ZZT) | 4 Ω - ensures minimal voltage deviation under load transients up to 3.4 mA AC ripple |
| Maximum Power Dissipation (PD) | 1 W at TA = 25 °C - supports continuous regulation in compact SMT layouts |
| Junction Temperature Range (TJ) | −55 °C to +175 °C - enables operation in automotive under-hood and industrial control environments |
| Leakage Current (IR) | <5 µA at 5.0 V - guarantees negligible standby current in battery-backed or low-power systems |
| Surge Current (IFSM) | 30 A (8.3 ms half-sine) - withstands common AC line surges and ESD-induced transients |
Pinout & Package
Package: DO-214AC (SMA), surface-mount, single-anode/single-cathode configuration. Cathode indicated by molded band. Matte tin-plated leads, solderable per J-STD-002.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference ground | Connected to circuit ground or lower-potential node during reverse-bias regulation |
| Cathode | Zener breakdown terminal / voltage reference output | Connected to regulated node; clamps voltage to 7.5 V when reverse biased above breakdown |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated chip junction | Enables stable long-term VZ drift performance and high reliability in humid environments |
| Low inductance construction | Minimizes ringing during fast transient suppression, critical for ESD and surge immunity |
| J-STD-020 Level 1 moisture sensitivity | Allows unlimited floor life before reflow-no baking required prior to assembly |
| RoHS and halogen-free compliance | Fulfills IPC-61249-2-21 requirements for environmentally constrained industrial and consumer products |
| UL 94V-0 molding compound | Provides flame-retardant encapsulation essential for safety-certified power supplies |
Applications
| USB Port Overvoltage Protection | Industrial Sensor Reference Supply |
|---|---|
Use Scenario: Clamping induced transients on USB VBUS lines during hot-plug or ESD events. IC Role / Device Role / Timing Role: Zener diode acting as shunt regulator and transient voltage suppressor. Use Value: Limits VBUS to ≤7.5 V during 30 A surge, protecting downstream USB controllers without adding series resistance. | Use Scenario: Providing stable 7.5 V bias for analog front-end amplifiers in 4–20 mA loop-powered sensors. IC Role / Device Role / Timing Role: Precision voltage reference and noise-filtering element in low-current analog signal chains. Use Value: Delivers <5 µA leakage and 4 Ω impedance to maintain ADC reference stability across −40 °C to +85 °C. |
| Automotive Body Control Module (BCM) Reset Circuit | Consumer IoT Power Sequencing |
Use Scenario: Generating clean reset threshold for microcontrollers in 12 V automotive subsystems. IC Role / Device Role / Timing Role: Zener-based voltage monitor triggering POR (Power-On Reset) logic. Use Value: Operates reliably from −40 °C to +125 °C ambient with 175 °C max junction rating, meeting AEC-Q200 stress requirements. | Use Scenario: Enabling controlled power-up sequencing of SoC and PMIC rails in battery-powered smart home devices. IC Role / Device Role / Timing Role: Clamp diode ensuring safe voltage ramp rate and preventing latch-up during cold-start. Use Value: Low 0.060 g mass and DO-214AC footprint minimize board space while supporting automated placement. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4733A | Same 5.1 V nominal VZ, but through-hole DO-41 package; higher ZZT (17 Ω) | Requires PCB through-hole layout; unsuitable for high-density SMT designs | Select 1SMA4737 for surface-mount volume production requiring automated placement and thermal efficiency |
| BZX84-C7V5 | SOT-23 package; lower PD (300 mW); tighter VZ tolerance (±5% same), but higher ZZT (15 Ω) | Limited to low-power signal-level clamping; cannot sustain 1 W continuous dissipation | Choose 1SMA4737 when >300 mW regulation or 30 A surge handling is required |
Compared with 1N4733A and BZX84-C7V5, the 1SMA4737 uniquely combines 1 W power handling, 4 Ω dynamic impedance, and DO-214AC SMT compatibility-making it optimal for compact, thermally demanding, and high-reliability regulation tasks.
Availability
1SMA4737 is available at Aetrix Electronics and suitable for USB power protection, industrial sensor biasing, automotive reset circuits, and consumer IoT power sequencing requiring stable component supply and full RoHS/halogen-free compliance.
Supply support for 1SMA4737 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated semiconductor manufacturer specializing in discrete power devices, analog ICs, and protection components for industrial, automotive, and consumer markets.
The 1SMA4737 belongs to TSC's SMA-series Zener diode family, engineered for high-volume surface-mount applications demanding robust surge immunity, tight voltage tolerance, and extended thermal reliability.
FAQ
What is the nominal zener voltage and tolerance of the 1SMA4737?
The 1SMA4737 has a nominal zener voltage of 7.5 V with a standard tolerance of ±5%, measured at 34 mA test current and 30 °C lead temperature. This tolerance ensures predictable clamping behavior in voltage regulation and overvoltage protection circuits where 7.1–7.9 V operation is acceptable.
What is the maximum continuous power dissipation for the 1SMA4737 at 60 °C ambient?
The 1SMA4737 delivers 1.25 W maximum continuous power dissipation at 60 °C ambient temperature when mounted on a PCB with adequate thermal relief (RTHJA < 76.8 K/W). This derating supports reliable operation in enclosed industrial enclosures without forced airflow.
Does the 1SMA4737 meet J-STD-020 moisture sensitivity requirements?
Yes, the 1SMA4737 is rated at J-STD-020 Level 1, meaning it has unlimited floor life before reflow soldering and requires no baking or dry-pack handling-simplifying manufacturing logistics for high-mix SMT production lines.
What is the typical leakage current of the 1SMA4737 at 5.0 V reverse bias?
The 1SMA4737 exhibits ≤5 µA typical leakage current at 5.0 V reverse bias and 25 °C ambient, enabling ultra-low quiescent current in battery-powered systems and precision analog references where standby power must remain below 25 µW.
Is the 1SMA4737 compatible with lead-free reflow profiles?
Yes, the 1SMA4737 features matte tin-plated leads compliant with J-STD-002 and is qualified for standard lead-free reflow profiles up to 260 °C peak temperature, supporting RoHS-compliant manufacturing without solderability degradation.
1SMA4737 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Series:
- -
- Package/Case:
- DO-214AC, SMA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 7.5 V
- Tolerance:
- ±5%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 4 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 5 V
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
1SMA4737 FAQ
1.How can I place an order for 1SMA4737 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMA4737 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 1SMA4737 reliable?
The price and inventory of 1SMA4737 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMA4737 is usually 5 days.
3.What payment methods are accepted for 1SMA4737?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMA4737 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMA4737?
1SMA4737 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMA4737 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 1SMA4737?
For technical support, including 1SMA4737 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMA4737 requirements.
6.How does Aetrix verify that 1SMA4737 is sourced from the original manufacturer or authorized distributors?
All 1SMA4737 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 1SMA4737 meets industry standards.
7.What is the process for return or replacement of 1SMA4737?
All 1SMA4737 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMA4737, 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 1SMA4737 part is unused and in its original packaging.
Return procedure for 1SMA4737:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMA4737 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
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
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…
