My Inquiry
My Account
onsemi SA75CA
- Part No.:
- SA75CA
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA75CA.pdf
- Description:
- TVS DIODE 75VWM 121VC DO15
- Quantity:
- Payment:
- Shipping:
Inventory:6,324
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SA75CA from Fairchild Semiconductor is a bidirectional 500 W transient voltage suppressor (TVS) diode in DO-15 package, with 75 V reverse stand-off voltage (VRWM), 83.3–92.1 V breakdown voltage (VBR), 121 V clamping voltage at peak pulse current, and 4.1 µA max reverse leakage at VRWM. It protects DC power lines and data interfaces against ESD, lightning-induced surges, and inductive switching transients in industrial control systems.
For engineers reviewing the SA75CA datasheet, pinout, applications, or equivalent options, key selection criteria include clamping performance under 10/1000 µs surge, unidirectional vs. bidirectional polarity handling, DO-15 thermal derating above 75°C, and compatibility with IEC 61000-4-2/4-5 surge immunity requirements.
Technical Context
The SA75CA employs a glass-passivated junction for stable avalanche characteristics and low incremental surge resistance. Its bidirectional structure enables symmetrical clamping in both polarities, eliminating need for polarity-aware PCB layout in AC-coupled or floating signal paths.
It delivers sub-5 ns response time from 0 V to breakdown in either direction and maintains clamping voltage ≤121 V at 4.1 A peak pulse current (IPPM), supporting robust protection of 24–48 V industrial bus interfaces such as RS-485, CAN FD physical layer, and PLC I/O modules.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 500 W on 10/1000 µs waveform - sustains single high-energy surges without failure |
| Reverse Stand-off Voltage | 75 V - defines maximum continuous operating voltage before clamping begins |
| Breakdown Voltage | 83.3–92.1 V at 1.0 mA - ensures reliable, repeatable avalanche initiation across temperature |
| Clamping Voltage | 121 V at IPPM - limits downstream voltage stress during worst-case surge events |
| Peak Pulse Current | 4.1 A on 10/1000 µs waveform - quantifies surge-handling capacity for system-level testing |
| Reverse Leakage | ≤4.1 µA at 75 V - minimizes standby power loss and avoids false triggering in high-impedance circuits |
| Response Time | <5.0 ns bidirectional - enables protection of fast-edge digital signals and analog sensor inputs |
Pinout & Package
DO-15 axial-leaded package with no cathode band; terminals are non-polarized due to bidirectional construction. Leads are 0.375" long for standard through-hole mounting and thermal dissipation at TA = 75°C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode (symmetrical) | Surge current path terminal | Either lead conducts surge current during positive or negative transients - no polarity assignment required |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR over lifetime and improved humidity resistance vs. epoxy-passivated alternatives |
| 500 W peak pulse rating | Meets Level 4 IEC 61000-4-5 (4 kV line-to-earth, 2 kV line-to-line) without external series impedance |
| Low incremental surge resistance | Reduces clamping voltage overshoot during fast-rising transients (e.g., EFT bursts) |
| Bidirectional symmetry | Eliminates need for orientation marking or polarity-sensitive routing in AC or differential signal paths |
Applications
| Industrial RS-485 Transceivers | PLC Analog Input Modules |
|---|---|
|
Use Scenario: Protection of half-duplex RS-485 bus lines exposed to field wiring surges in factory automation cabinets. IC Role / Device Role: Primary surge clamp placed between A/B differential pair and transceiver IC. Use Value: Limits transient voltage to ≤121 V, preserving transceiver integrity during 4 kV IEC 61000-4-5 surges without de-rating. |
Use Scenario: Overvoltage protection on 4–20 mA current loop inputs subjected to accidental 24 V DC miswiring or relay coil flyback. IC Role / Device Role: Bidirectional shunt clamp across input terminals upstream of signal conditioning circuitry. Use Value: Clamps both positive and negative transients symmetrically while drawing <4.1 µA at 24 V nominal, avoiding measurement offset. |
| Smart Meter Communication Interfaces | DC Power Rail Protection (24–48 V) |
|
Use Scenario: Surge suppression on PLC or RF module supply rails in utility smart meters installed in outdoor meter boxes. IC Role / Device Role: Secondary protection stage after primary MOV, placed near communication IC power pins. Use Value: Fast <5 ns response captures residual fast-edge energy missed by slower MOVs, reducing risk of IC latch-up. |
Use Scenario: Protection of 48 V DC input to motor drive control boards exposed to inductive load switching in HVAC systems. IC Role / Device Role: Parallel-connected TVS across main DC input terminals, rated for repeated 500 W pulses. Use Value: Withstands ≥1000 cycles at 8.3 ms half-sine surge per JEDEC, enabling long-term reliability in cyclic industrial environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ75CA | DO-214AA package, 600 W rating, 123 V clamping at same IPPM | Higher thermal mass but requires SMT footprint; less suitable for through-hole legacy designs | Select when board space is constrained and reflow assembly is available |
| P6SMB75CA | Same DO-214AA package, 600 W rating, 123 V clamping, tighter VBR tolerance (±5%) | Improved parametric consistency but lacks axial-leaded mechanical robustness for high-vibration environments | Select when batch-to-batch VBR stability is critical and vibration is not a concern |
Compared with SMBJ75CA and P6SMB75CA, the SA75CA offers proven mechanical reliability in through-hole industrial assemblies, lower thermal resistance in leaded configuration, and direct compatibility with legacy DO-15 footprints-making it optimal for retrofit, repair, and ruggedized control hardware where axial mounting is specified.
Availability
SA75CA is available at Aetrix Electronics and suitable for industrial automation, smart metering, and DC power rail protection requiring stable component supply and long-lifecycle support.
Supply support for SA75CA 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 designer of high-performance analog and discrete semiconductors, with leadership in power management, signal conditioning, and protection devices.
The SAxxCA series was developed specifically for industrial-grade transient suppression in harsh electromagnetic environments, emphasizing robustness, bidirectional symmetry, and compliance with IEC 61000-4-x standards.
FAQ
What is the clamping voltage of the SA75CA at its rated peak pulse current?
The SA75CA has a maximum clamping voltage (VC) of 121 V at its peak pulse current (IPPM) of 4.1 A under the standard 10/1000 µs waveform. This value is measured per JEDEC test conditions and guarantees that downstream circuitry sees no more than 121 V during a full-rated surge event. The SA75CA maintains this clamping performance across its specified operating junction temperature range up to +175°C.
Is the SA75CA unidirectional or bidirectional, and how does that affect PCB layout?
The SA75CA is a bidirectional TVS diode, indicated by the "CA" suffix, meaning it provides symmetrical clamping for both positive and negative transients. Unlike unidirectional variants, it has no cathode band and requires no polarity-specific orientation on the PCB. This simplifies layout for AC-coupled interfaces like RS-485 or transformer-isolated power supplies, where signal polarity may reverse or be undefined.
What is the maximum reverse leakage current for the SA75CA at its rated stand-off voltage?
The SA75CA exhibits a maximum reverse leakage current (IR) of 4.1 µA at its reverse stand-off voltage (VRWM) of 75 V and TA = 25°C. This low leakage ensures minimal impact on high-impedance sensing circuits and prevents unnecessary power drain in battery-backed or energy-harvesting systems. Leakage remains within specification up to the full operating temperature range.
Can the SA75CA be used in parallel to increase surge handling capacity?
No, the SA75CA is not recommended for parallel operation due to mismatch in breakdown voltage (VBR) tolerance (83.3–92.1 V), which causes uneven current sharing and potential thermal runaway. For higher surge ratings, select a single device with higher PPPM (e.g., 1500 W TVS) or implement staged protection with upstream MOVs and downstream SA75CA as a precision clamp.
Does the SA75CA meet IEC 61000-4-5 surge immunity requirements?
Yes, the SA75CA's 500 W peak pulse power rating and 121 V clamping voltage enable compliance with IEC 61000-4-5 Level 4 (4 kV line-to-earth, 2 kV line-to-line) when properly integrated with appropriate series impedance and PCB layout. Its <5 ns response time ensures effective suppression of fast-rising components of the surge waveform that could otherwise bypass slower protection elements.
SA75CA 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:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 75V
- Voltage - Breakdown (Min):
- 83.3V
- Voltage - Clamping (Max) @ Ipp:
- 121V
- Current - Peak Pulse (10/1000µs):
- 4.1A
- 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
SA75CA FAQ
1.How can I place an order for SA75CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SA75CA 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 SA75CA reliable?
The price and inventory of SA75CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA75CA is usually 5 days.
3.What payment methods are accepted for SA75CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA75CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA75CA?
SA75CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA75CA 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 SA75CA?
For technical support, including SA75CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA75CA requirements.
6.How does Aetrix verify that SA75CA is sourced from the original manufacturer or authorized distributors?
All SA75CA 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 SA75CA meets industry standards.
7.What is the process for return or replacement of SA75CA?
All SA75CA units undergo pre-shipment inspection (PSI). If there is an issue with SA75CA, 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 SA75CA part is unused and in its original packaging.
Return procedure for SA75CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SA75CA 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…
