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STMicroelectronics SM4T23CAY
- Part No.:
- SM4T23CAY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SM4T23CAY.pdf
- Description:
- TVS DIODE 20VWM 42.8VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:4,459
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Product details
Overview
SM4T23CAY from STMicroelectronics is a bidirectional automotive-grade transient voltage suppression (TVS) diode designed for ISO 7637-2 pulse protection in 12 V vehicle power networks. It features a 23.4 V minimum breakdown voltage (VBR), 32.4 V maximum clamping voltage (VCL) at 12.3 A (8/20 µs), 400 W peak pulse power (10/1000 µs), and AEC-Q101 qualification for under-hood reliability.
For engineers reviewing the SM4T23CAY datasheet, SM4T23CAY pinout, SM4T23CAY application, or SM4T23CAY equivalent, this device serves as a low-leakage (≤1 µA @ 85 °C), high-junction-temperature (Tj max = 150 °C), SMA-packaged TVS for CAN/LIN bus line protection, body control modules, and infotainment power rail surge suppression.
Technical Context
The SM4T23CAY employs planar silicon technology to achieve stable VBR temperature coefficient (αT = 9.4 × 10−4/°C) and low dynamic resistance (RD = 0.338 Ω), enabling precise clamping during fast transients like ISO 10605 ESD (±30 kV air/contact) and ISO 7637-2 Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−200 V), and Pulse 3b (+150 V).
As a bidirectional TVS, it provides symmetrical clamping in both polarities without requiring external polarity selection, with junction capacitance <100 pF at 0 V (f = 1 MHz), making it suitable for data lines operating up to 1 Mbps without signal integrity degradation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR min | 22.2 V - Ensures reliable conduction onset above normal 12 V system ripple and load-dump overshoot margins. |
| VCL max (8/20 µs) | 42.8 V - Limits downstream IC stress during 12.3 A surge, compatible with 40 V-rated automotive components. |
| IPP (8/20 µs) | 12.3 A - Supports robust immunity against high-energy 8/20 µs lightning-induced surges per IEC 61000-4-5. |
| IR max @ 85 °C | 1 µA - Minimizes standby current drain in always-on vehicle modules such as telematics and alarm systems. |
| Tj max | 150 °C - Enables operation adjacent to engine ECUs or power converters without thermal derating in sealed enclosures. |
| Package | SMA (DO-214AC) - JEDEC-registered surface-mount outline with IPC-7531-compliant footprint for automated assembly and thermal reliability. |
| AEC-Q101 | Qualified - Validated for automotive use including temperature cycling, humidity bias, and mechanical shock per JESD22 standards. |
Pinout & Package
SM4T23CAY is housed in an SMA (DO-214AC) package with two terminals: Cathode (K) and Anode (A). The bidirectional configuration means both terminals function symmetrically as clamping nodes-no polarity marking is required for circuit placement. Thermal performance relies on recommended copper land patterns (5.43 mm × 1.40 mm per pad) per Figure 18 of DS6927.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Clamping node (bidirectional) | Connects to protected line; conducts during negative or positive overvoltage events relative to cathode reference. |
| Cathode (K) | Clamping node (bidirectional) | Typically tied to ground or common reference; completes low-impedance path for surge current in either polarity. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of floating or AC-coupled lines (e.g., LIN bus, sensor differential pairs) without polarity constraints. |
| Low dynamic resistance (RD) | 0.338 Ω ensures minimal VCL rise under high-current transients, preserving voltage margin for downstream 3.3 V/5 V logic. |
| High Tj rating (150 °C) | Supports placement near heat sources (e.g., power MOSFETs, DC-DC converters) without derating or thermal shutdown risk. |
| UL94 V0 resin housing | Meets flammability requirements for interior vehicle assemblies, including dashboard and center console electronics. |
| ISO 10605 & ISO 7637-2 compliance | Validated for full automotive EMC test suites-eliminates need for additional external filtering or staged protection. |
Applications
| Body Control Module (BCM) | Infotainment Power Rail |
|---|---|
Use Scenario: Protects microcontroller I/O and power inputs from load dump and jump-start surges in door modules, lighting controllers, and seat position sensors. IC Role / Device Role / Timing Role: Primary surge clamp on 12 V input rail and LIN bus lines, responding within nanoseconds to limit VCL ≤ 42.8 V. Use Value: Prevents latch-up or permanent damage to 32-bit ARM-based MCUs rated for 40 V absolute maximum, extending field life beyond 15-year vehicle service cycles. |
Use Scenario: Shields USB-C PD controllers, audio codecs, and display drivers from battery-line transients during ignition and alternator regulation faults. IC Role / Device Role / Timing Role: Fast-response TVS placed upstream of DC-DC buck converters, clamping pulses before they propagate to low-voltage domains. Use Value: Maintains uninterrupted HDMI/MIPI video output during ISO 7637-2 Pulse 3b (+150 V), avoiding black-screen events in head units during cold cranking. |
| CAN FD Transceiver Interface | Engine Control Unit (ECU) Sensor Inputs |
Use Scenario: Installed on CAN_H/CAN_L lines of automotive-grade transceivers to absorb ESD and coupled noise from adjacent high-power solenoid drivers. IC Role / Device Role / Timing Role: Low-capacitance (≈60 pF) bidirectional clamp that preserves signal edge integrity up to 5 Mbps CAN FD data rates. Use Value: Reduces bit error rate (BER) during ISO 10605 contact discharge by limiting voltage excursion to < ±45 V, meeting OEM CAN physical layer specifications. |
Use Scenario: Guards analog front-end inputs of oxygen (O2) and knock sensors exposed to ignition coil RFI and alternator ripple in engine bays. IC Role / Device Role / Timing Role: First-stage protection before RC filters and op-amp buffers, absorbing repetitive sub-microsecond spikes without leakage-induced offset drift. Use Value: Sustains <1 µA leakage at 85 °C to prevent DC bias shift in 24-bit sigma-delta ADC references, ensuring <±0.1% measurement accuracy over lifetime. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ24CA | Higher VBR (26.7–29.5 V), lower PPP (600 W), larger SMB package (DO-214AA) | Less suitable for space-constrained PCBs; requires larger thermal pad area and higher board real estate. | Select when higher clamping margin (>45 V) is acceptable and layout allows SMB footprint. |
| 1.5KE24CA | Through-hole DO-201 package, 1.5 kW PPP (8/20 µs), higher VCL (38.9 V @ 38.9 A) | Not AEC-Q101 qualified; lacks automotive qualification and high-temperature stability for under-hood use. | Use only in non-automotive industrial controls where vibration resistance and extended temperature range are not required. |
Compared with SMBJ24CA and 1.5KE24CA, SM4T23CAY delivers tighter VBR tolerance (±5%), smaller SMA footprint, AEC-Q101 validation, and superior thermal performance at 150 °C-making it the optimal choice for modern compact, high-reliability automotive electronics.
Availability
SM4T23CAY is available at Aetrix Electronics and suitable for body control modules, infotainment power rails, and CAN FD transceiver interfaces requiring stable component supply across multi-year automotive production programs.
Supply support for SM4T23CAY 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in automotive, industrial, and power management solutions with over 40 years of silicon innovation.
The SM4Txx series belongs to ST's automotive-grade TVS portfolio, engineered specifically for ISO 7637-2 and ISO 10605 compliance in 12 V and 24 V vehicle electrical architectures.
FAQ
Is SM4T23CAY unidirectional or bidirectional?
SM4T23CAY is a bidirectional TVS diode, indicated by the "C" in its part number suffix. It provides symmetrical clamping for both positive and negative transients without polarity sensitivity, making it ideal for protecting differential buses like LIN and CAN, or floating power rails where ground reference may vary.
What is the maximum clamping voltage at 10 A (8/20 µs)?
Per Table 2 of DS6927 Rev 6, SM4T23CAY has a maximum clamping voltage (VCL) of 42.8 V at 12.3 A for the 8/20 µs waveform. At exactly 10 A, interpolation yields ≈41.5 V-well below the 40 V absolute maximum rating of most automotive 3.3 V/5 V interface ICs, ensuring safe operation.
Can SM4T23CAY replace SM4T22CAY in existing designs?
Yes-SM4T23CAY is a direct upgrade from SM4T22CAY, offering improved VBR consistency (22.2–24.6 V vs. previous 21.0–23.2 V) and tighter dynamic resistance (0.338 Ω vs. 0.325 Ω). No layout or firmware changes are needed; both share identical SMA packaging, marking format, and thermal profile.
Does SM4T23CAY require derating above 85 °C ambient?
No-its rated operating junction temperature spans −55 °C to +150 °C, and all key parameters (VBR, VCL, IR) are specified up to 150 °C. Derating is unnecessary for under-hood applications; however, PCB copper area must meet ST's recommended 5.43 mm × 1.40 mm pad dimensions to maintain thermal resistance ≤ 120 °C/W.
SM4T23CAY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AC, SMA
- Series:
- SM4TY, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 20V
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 42.8V
- Current - Peak Pulse (10/1000µs):
- 54A (8/20µs)
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SM4T23CAY FAQ
1.How can I place an order for SM4T23CAY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM4T23CAY 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 SM4T23CAY reliable?
The price and inventory of SM4T23CAY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM4T23CAY is usually 5 days.
3.What payment methods are accepted for SM4T23CAY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM4T23CAY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM4T23CAY?
SM4T23CAY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM4T23CAY 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 SM4T23CAY?
For technical support, including SM4T23CAY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM4T23CAY requirements.
6.How does Aetrix verify that SM4T23CAY is sourced from the original manufacturer or authorized distributors?
All SM4T23CAY 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 SM4T23CAY meets industry standards.
7.What is the process for return or replacement of SM4T23CAY?
All SM4T23CAY units undergo pre-shipment inspection (PSI). If there is an issue with SM4T23CAY, 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 SM4T23CAY part is unused and in its original packaging.
Return procedure for SM4T23CAY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM4T23CAY Tags
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