My Inquiry
My Account
onsemi SA54A
- Part No.:
- SA54A
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA54A.pdf
- Description:
- TVS DIODE 54VWM 87.1VC DO15
- Quantity:
- Payment:
- Shipping:
Inventory:6,010
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SA54A from Fairchild Semiconductor is a unidirectional 500 W transient voltage suppressor (TVS) diode designed for primary overvoltage protection in DC power lines and signal interfaces. It features a 54 V reverse stand-off voltage (VRWM), 60.0–66.3 V breakdown voltage (VBR) at 1.0 mA, 87.1 V clamping voltage (VC) at 5.7 A peak pulse current (IPPM), and operates up to +175 °C junction temperature.
For engineers reviewing the SA54A datasheet, pinout, applications, or equivalent options, key selection criteria include clamping performance under 10/1000 μs surge, low leakage (<1.0 μA at 54 V), fast response time (<1.0 ps), glass-passivated junction reliability, and DO-15 package compatibility with standard PCB layouts for industrial power supply and automotive ECU protection.
Technical Context
The SA54A is a unidirectional silicon avalanche diode optimized for transient suppression on DC rails. Its clamping action begins at 60.0 V minimum breakdown and limits voltage to ≤87.1 V during a 5.7 A 10/1000 μs surge, delivering predictable energy absorption without thermal runaway.
It uses a glass-passivated junction for stable leakage (<1.0 μA at VRWM) and robust surge endurance. With a maximum operating junction temperature of +175 °C and 1.0 W steady-state power dissipation at 75 °C ambient (0.375" lead length), it supports high-reliability deployment in constrained thermal environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 54 V - Maximum continuous reverse operating voltage before significant leakage; defines safe DC rail margin. |
| VBR (min/max) | 60.0 / 66.3 V at 1.0 mA - Confirmed avalanche onset range; ensures consistent turn-on across production lots. |
| VC @ IPPM | 87.1 V at 5.7 A - Clamped voltage during standardized 10/1000 μs surge; determines protected circuit's maximum stress level. |
| PPPM | 500 W - Peak pulse power rating on 10/1000 μs waveform; quantifies single-event surge handling capability. |
| IR @ VRWM | <1.0 μA - Reverse leakage at rated stand-off voltage; critical for low-power standby circuits and battery-backed systems. |
| TJ max | +175 °C - Maximum junction temperature; enables operation in under-hood automotive or enclosed industrial enclosures. |
Pinout & Package
SA54A is housed in a DO-15 axial-leaded package with cathode indicated by a color band. The device has two terminals: anode and cathode. Lead length is specified as 0.375" for thermal derating compliance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal in forward bias; connected to protected line ground or low-side return path. | Reference point for unidirectional clamping; must be tied to lowest potential node in protected circuit. |
| Cathode | Current exit terminal in forward bias; marked by color band; connected to protected line (e.g., +54 V rail). | Defines polarity-sensitive connection; reverse connection renders device non-functional for overvoltage suppression. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable leakage performance and long-term reliability under humidity and thermal cycling stress. |
| 500 W peak pulse power (10/1000 μs) | Supports IEC 61000-4-5 Level 4 surge immunity (4 kV line-to-ground) in properly impedance-matched circuits. |
| Clamping voltage ≤87.1 V at 5.7 A | Provides defined overvoltage ceiling for downstream ICs rated to 100 V absolute maximum, enabling robust system-level protection. |
| Response time <1.0 ps | Engages before most semiconductor damage mechanisms initiate, preserving integrity of fast-switching power stages and microcontrollers. |
| Low IR <1.0 μA at VRWM | Minimizes standby power loss and avoids false triggering in high-impedance sensing or battery-powered applications. |
Applications
| Automotive Power Supply Protection | Industrial PLC Input Protection |
|---|---|
Use Scenario: Protecting 48 V DC power inputs in engine control units against load dump transients per ISO 7637-2 Pulse 5a. IC Role / Device Role / Timing Role: Primary unidirectional TVS clamp placed upstream of DC-DC converter input stage. Use Value: Limits transient voltage to ≤87.1 V, preventing damage to 100 V-rated MOSFETs and gate drivers while surviving 500 W surges. |
Use Scenario: Safeguarding 24 V digital input channels in programmable logic controllers exposed to inductive switching noise. IC Role / Device Role / Timing Role: Standoff-mode protector across input terminals, shunting induced spikes to common ground. Use Value: Sub-1.0 μA leakage avoids false logic states; fast <1.0 ps response prevents latch-up in optocoupler input stages. |
| Telecom DC Feeder Line Protection | Renewable Energy Charge Controller |
Use Scenario: Secondary overvoltage guard on -48 V telecom rectifier outputs subject to lightning-induced surges. IC Role / Device Role / Timing Role: Unidirectional clamp referenced to negative rail, absorbing positive-going transients only. Use Value: 54 V VRWM aligns with nominal -48 V system tolerance; 87.1 V VC ensures compatibility with -100 V-rated interface ICs. |
Use Scenario: Protecting MPPT controller inputs connected to solar panel strings operating up to 60 V open-circuit. IC Role / Device Role / Timing Role: Front-end TVS on PV+ line, clamping lightning-induced surges before they reach buck converter MOSFETs. Use Value: +175 °C TJ rating supports outdoor enclosure mounting; DO-15 package allows manual rework and high-voltage creepage spacing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ54A (ON Semiconductor) | Same VRWM (54 V), but SMB package (surface-mount); lower PPPM (600 W), higher VC (88.0 V at 6.8 A). | Requires PCB redesign for SMT layout; better suited for space-constrained consumer electronics vs. through-hole industrial modules. | Select SMBJ54A only when board area is critical and thermal management supports SMT power dissipation. |
| P6KE56A (Littelfuse) | Higher VRWM (56 V), same DO-15 package; slightly higher VBR (62.2–68.8 V); VC = 93.6 V at 5.3 A. | Looser voltage margin may allow higher residual stress on downstream 100 V-rated components during worst-case surges. | Choose P6KE56A only if system design tolerates ≥93.6 V clamping and requires broader vendor sourcing flexibility. |
Compared with SMBJ54A and P6KE56A, the SA54A offers tighter VBR tolerance (60.0–66.3 V), lower clamping (87.1 V), and proven DO-15 mechanical robustness for high-vibration environments-making it preferred for automotive and industrial applications where reliability trumps miniaturization.
Availability
SA54A is available at Aetrix Electronics and suitable for automotive power supply protection, industrial PLC input protection, telecom DC feeder line protection, and renewable energy charge controller applications requiring stable component supply and long-lifecycle support.
Supply support for SA54A 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 was a leading designer of high-performance analog and power semiconductors, acquired by ON Semiconductor in 2016; its legacy TVS portfolio remains widely deployed in industrial and automotive systems.
The SA54A belongs to Fairchild's SAxxA series of 500 W unidirectional TVS diodes, engineered specifically for ruggedized overvoltage protection in harsh-environment DC power systems with demanding thermal and surge requirements.
FAQ
What is the clamping voltage of SA54A under a standard 10/1000 μs surge?
The SA54A clamps to a maximum of 87.1 V when subjected to its rated peak pulse current of 5.7 A on the 10/1000 μs waveform. This value is measured per industry-standard test conditions (TA = 25°C) and defines the upper voltage limit imposed on protected circuitry during transient events. The SA54A maintains this clamping performance consistently due to its tightly controlled avalanche characteristics and glass-passivated junction structure.
Is SA54A unidirectional or bidirectional, and how is polarity identified?
The SA54A is a unidirectional transient voltage suppressor, meaning it conducts only during reverse-biased overvoltage events. Polarity is identified by a color band on the cathode end of the DO-15 package; the banded end connects to the protected line (e.g., +54 V rail), while the unbanded anode connects to ground or return. Bidirectional variants in the same family use the "C" suffix (e.g., SA54CA).
What is the maximum junction temperature rating for SA54A?
The SA54A has a maximum operating junction temperature (TJ) of +175 °C, enabling reliable operation in high-temperature environments such as engine compartments, enclosed industrial drives, or solar charge controllers mounted in direct sunlight. This rating is validated under specified thermal conditions, including 0.375" lead length and proper PCB copper pour for heat spreading.
Does SA54A meet any international surge immunity standards?
The SA54A's 500 W peak pulse power rating on the 10/1000 μs waveform aligns with the energy requirements of IEC 61000-4-5 Level 4 (4 kV line-to-ground) when used with appropriate series impedance. While the device itself is not certified to a standard, its electrical parameters enable compliant system-level designs for industrial and automotive applications when integrated per recommended layout guidelines.
How does SA54A compare to SA54CA in terms of electrical behavior?
The SA54A is unidirectional and clamps only reverse surges, whereas the SA54CA is bidirectional and provides symmetrical clamping for both polarities. Their breakdown voltages (VBR) and clamping voltages (VC) are identical in magnitude but apply to opposite directions: SA54A protects against positive transients on grounded systems, while SA54CA protects floating or AC-coupled lines where polarity reversal occurs. Both share the same DO-15 package and thermal ratings.
SA54A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-204AC, DO-15, Axial
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 54V
- Voltage - Breakdown (Min):
- 60V
- Voltage - Clamping (Max) @ Ipp:
- 87.1V
- Current - Peak Pulse (10/1000µs):
- 5.7A
- Power - Peak Pulse:
- 500W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-15
SA54A FAQ
1.How can I place an order for SA54A through Aetrix?
Please submit a Request for Quotation (RFQ) for SA54A 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 SA54A reliable?
The price and inventory of SA54A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA54A is usually 5 days.
3.What payment methods are accepted for SA54A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA54A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA54A?
SA54A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA54A 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 SA54A?
For technical support, including SA54A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA54A requirements.
6.How does Aetrix verify that SA54A is sourced from the original manufacturer or authorized distributors?
All SA54A 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 SA54A meets industry standards.
7.What is the process for return or replacement of SA54A?
All SA54A units undergo pre-shipment inspection (PSI). If there is an issue with SA54A, 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 SA54A part is unused and in its original packaging.
Return procedure for SA54A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SA54A 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
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…
