My Inquiry
My Account
onsemi SA43A
- Part No.:
- SA43A
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA43A.pdf
- Description:
- TVS DIODE 43VWM 69.4VC AXIAL
- Quantity:
- Payment:
- Shipping:
Inventory:3,079
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SA43A from Fairchild Semiconductor is a unidirectional 500 W transient voltage suppressor (TVS) diode in DO-15 package, with 43 V reverse stand-off voltage (VRWM), 47.8–52.8 V breakdown voltage (VBR), and 69.4 V clamping voltage (VC) at 7.2 A peak pulse current. It provides fast surge protection for DC power rails and I/O lines in industrial control and automotive electronics.
For engineers reviewing the SA43A datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, DO-15 terminal mapping, bidirectional variant context (SA43CA), clamping performance under 10/1000 μs transients, and real-world selection guidance against comparable TVS diodes.
Technical Context
The SA43A is a glass-passivated, unidirectional avalanche diode designed to clamp transient overvoltages before they damage downstream circuitry. Its low incremental surge resistance and sub-1.0 ps response time (0 V to BV) enable effective suppression of ESD, lightning-induced surges, and inductive switching spikes.
Rated for 500 W peak pulse power on 10/1000 μs waveform and 1.0 W steady-state dissipation at 75°C with 0.375" lead length, it operates up to +175°C junction temperature and supports non-repetitive forward surge currents up to 70 A (8.3 ms half-sine).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power (10/1000 μs) | 500 W - sustains single high-energy transients without failure |
| Reverse Stand-off Voltage (VRWM) | 43 V - maximum continuous DC or RMS voltage before clamping begins |
| Breakdown Voltage (VBR) | 47.8–52.8 V @ 1.0 mA - guaranteed avalanche initiation range for reliable triggering |
| Clamping Voltage (VC) | 69.4 V @ 7.2 A - maximum voltage seen by protected circuit during rated surge |
| Peak Pulse Current (IPPM) | 7.2 A - peak current handled at VC under standard 10/1000 μs test waveform |
| Reverse Leakage (IR) | <1.0 μA @ 43 V - minimal standby power loss and signal integrity impact |
| Junction Temperature Range | −65°C to +175°C - suitable for under-hood automotive and industrial environments |
Pinout & Package
SA43A uses the industry-standard DO-15 axial-leaded package. The cathode is marked by a color band on the body; the anode is the unmarked end. Leads are tinned and suitable for wave or hand soldering.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unbanded end) | Current entry point in forward bias; connected to ground or low-side reference | Completes clamping path when transient exceeds VRWM; must be routed with low-inductance connection to return plane |
| Cathode (banded end) | Protected line connection; clamps to anode during overvoltage | Connected to the line being protected (e.g., 48 V rail); voltage across device rises to VC only during surge |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Enhances long-term reliability and moisture resistance vs. epoxy-passivated alternatives |
| Sub-1.0 ps response time (0 V → BV) | Clamps before most microsecond-scale transients fully develop, protecting sensitive IC inputs |
| Low incremental surge resistance | Minimizes voltage overshoot during high di/dt events, improving clamping precision |
| 500 W peak pulse rating (10/1000 μs) | Matches IEC 61000-4-5 Level 4 surge immunity requirements for industrial ports |
| DO-15 mechanical compatibility | Enables drop-in replacement in legacy designs using standard axial footprint and mounting holes |
Applications
| Industrial PLC I/O Protection | Automotive Body Control Module (BCM) |
|---|---|
Use Scenario: Protecting 24–48 V digital input channels in programmable logic controllers from field-wiring induced surges and relay contact bounce. IC Role / Device Role / Timing Role: Unidirectional TVS placed between input terminal and ground to shunt transients before reaching optocoupler or MCU GPIO. Use Value: Clamps 43 V nominal line to ≤69.4 V during 7.2 A surge, preventing latch-up or permanent damage to isolation components rated for 75 V max. |
Use Scenario: Safeguarding LIN bus and sensor supply lines in BCMs exposed to load dump and jump-start conditions. IC Role / Device Role / Timing Role: Primary overvoltage clamp on 12 V/48 V auxiliary rails feeding Hall-effect sensors and LED drivers. Use Value: Withstands 70 A non-repetitive forward surge and operates up to +175°C, meeting AEC-Q101 stress requirements for under-dash placement. |
| DC Power Supply Input Stage | Telecom Remote Power Feeds |
Use Scenario: Front-end surge protection for 48 V telecom rectifier outputs and PoE-powered equipment inputs. IC Role / Device Role / Timing Role: First-line TVS in series with fuse and common-mode choke to absorb differential-mode transients per IEC 61000-4-5. Use Value: 500 W rating handles 2 kV/1 kA combination wave surges; DO-15 form factor allows compact layout near connector entry point. |
Use Scenario: Protecting remote radio units powered via 48 V DC over long outdoor cables susceptible to induced lightning energy. IC Role / Device Role / Timing Role: Bidirectional clamping (using SA43CA variant) across power pair to suppress both polarity surges without polarity dependence. Use Value: Identical VBR and VC specs as SA43A ensure consistent protection level; CA suffix denotes symmetrical bidirectional behavior for floating supply applications. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ43A | Same DO-214AC (SMA) package; 43 V VRWM, 69.4 V VC @ 7.2 A; slightly higher IR (5 μA max @ VRWM) | Surface-mount alternative requiring PCB redesign; lower thermal resistance than DO-15 but less robust mechanical mounting | Select when automated assembly and space constraints favor SMD; verify board-level thermal relief for 1.0 W dissipation |
| Vishay 1.5KE43A | Higher power (1500 W), same DO-15 package; 43 V VRWM, 69.4 V VC @ 21.7 A; larger case diameter (5.6 mm vs. 3.6 mm) | Used where higher surge margin is required (e.g., AC mains interfaces); not mechanically interchangeable due to size and lead spacing | Choose for enhanced ruggedness in harsh environments; confirm mechanical fit and creepage/clearance compliance |
Compared with SMAJ43A and 1.5KE43A, SA43A offers optimal balance of axial-leaded robustness, 500 W surge handling, and tight clamping for cost-sensitive industrial 48 V systems-without requiring SMT retooling or oversized packaging.
Availability
SA43A is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and telecom power supply applications requiring stable component supply and long-term obsolescence management.
Supply support for SA43A 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
Fairchild Semiconductor (now part of ON Semiconductor) is a global leader in power management, analog, and discrete semiconductors, with core expertise in high-reliability protection devices and efficient power conversion.
The SAxxA series was engineered specifically for robust, cost-effective transient suppression in DC power distribution networks-targeting industrial controls, automotive subsystems, and infrastructure equipment where DO-15 form factor and proven surge endurance are critical.
FAQ
What is the clamping voltage of SA43A and how does it protect downstream circuits?
The SA43A has a maximum clamping voltage (VC) of 69.4 V at 7.2 A peak pulse current on a 10/1000 μs waveform. This means that during a transient event, the voltage across the SA43A will not exceed 69.4 V, limiting the stress imposed on downstream components such as MCUs, transceivers, or power regulators. Its fast response time (<1.0 ps from 0 V to breakdown) ensures clamping occurs before damaging overvoltage reaches sensitive nodes. The SA43A achieves this while maintaining low leakage (<1.0 μA at 43 V), minimizing impact on normal operation.
Is SA43A unidirectional or bidirectional, and what does the 'C' suffix indicate?
The SA43A is a unidirectional TVS diode, intended for use on grounded or referenced DC lines where surge polarity is known. The 'C' suffix-as in SA43CA-denotes the bidirectional variant, which provides symmetrical clamping in both polarities and is used in floating or AC-coupled applications like telecom data lines or LIN bus. SA43A itself has a cathode band marking; SA43CA has no band and behaves identically in either direction. Both share identical VRWM, VBR, and VC values per the datasheet.
Can SA43A replace SA43CA in a bidirectional circuit?
No, SA43A cannot directly replace SA43CA in a bidirectional circuit because SA43A only clamps in one direction (cathode-to-anode). If reverse polarity transients occur, SA43A would conduct heavily and likely fail, whereas SA43CA clamps equally in both directions. Using SA43A in place of SA43CA risks catastrophic failure during negative-going surges. For true bidirectional protection, SA43CA-or two back-to-back SA43A diodes-is required. Always match device polarity type to system surge profile.
What is the maximum operating temperature and thermal derating behavior of SA43A?
The SA43A has a maximum operating junction temperature (TJ) of +175°C and a storage temperature range of −65°C to +175°C. Its steady-state power dissipation is rated at 1.0 W with 0.375" lead length at TA = 75°C, and derates linearly to zero at +175°C ambient (per Figure 5 in the datasheet). At 100°C ambient, usable power drops to ~0.67 W. Designers must ensure adequate PCB copper area or airflow to maintain junction temperature within limit during sustained surge duty cycles.
How does SA43A compare to 1N5375B or other Zener-based transient suppressors?
Unlike general-purpose Zener diodes such as 1N5375B (43 V, 5 W), the SA43A is optimized for transient suppression: it delivers 500 W peak pulse power (vs. 5 W continuous), features glass passivation for reliability, and exhibits faster response (<1.0 ps vs. ~10 ns typical for Zeners). Its low incremental resistance yields tighter clamping (69.4 V VC vs. >80 V for Zener equivalents under surge), and its 70 A surge rating far exceeds Zener surge capability. SA43A is purpose-built for IEC-compliant surge events; Zeners are unsuitable for repetitive or high-energy transients.
SA43A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-204AC, DO-15, Axial
- Series:
- MiniMosorb™
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 43V
- Voltage - Breakdown (Min):
- 47.8V
- Voltage - Clamping (Max) @ Ipp:
- 69.4V
- Current - Peak Pulse (10/1000µs):
- 7.2A
- Power - Peak Pulse:
- 500W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- Axial
SA43A FAQ
1.How can I place an order for SA43A through Aetrix?
Please submit a Request for Quotation (RFQ) for SA43A 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 SA43A reliable?
The price and inventory of SA43A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA43A is usually 5 days.
3.What payment methods are accepted for SA43A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA43A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA43A?
SA43A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA43A 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 SA43A?
For technical support, including SA43A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA43A requirements.
6.How does Aetrix verify that SA43A is sourced from the original manufacturer or authorized distributors?
All SA43A 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 SA43A meets industry standards.
7.What is the process for return or replacement of SA43A?
All SA43A units undergo pre-shipment inspection (PSI). If there is an issue with SA43A, 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 SA43A part is unused and in its original packaging.
Return procedure for SA43A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SA43A Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…
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…
