Specifications
| Attribute | Value |
| Supplier | STMicroelectronics |
| Package / Case | Tape & Reel (TR),Cut Tape (CT) |
| Series | Automotive, AEC-Q101, SM4TY, TRANSIL™ |
| Part Status | Active |
| Type | Zener |
| Bidirectional Channels | 1 |
| Voltage - Reverse Standoff (Typ) | 15V |
| Voltage - Breakdown (Min) | 16.7V |
| Voltage - Clamping (Max) @ Ipp | 32.5V |
| Current - Peak Pulse(10 / 1000µs) | 71A (8/20µs) |
| Power - Peak Pulse | 400W |
| Power Line Protection | No |
| Applications | Automotive |
| Operating Temperature | -55°C ~ 150°C (TJ) |
| Mounting Type | Surface Mount |
Overview
Description
SM4T18CAY is a four-channel surface-mount TVS diode array for transient protection. It guards up to four lines (ESD and surge) by shunting transient energy to a common ground. The “18” usually points to a nominal 18 V working/standoff voltage, but exact figures (Vwm, Vclamp, leakage, capacitance, current rating) vary by vendor—check the datasheet. Features commonly include low input capacitance for high-speed lines and fast response. Typical applications: protecting interfaces such as USB, CAN/LIN, Ethernet, or other multi-line data/power lines, placed close to connectors. To use, mount near the connector with a solid ground reference and follow recommended PCB layout to minimize loop area.
Pinout
Pin count: 2 pins — Anode and Cathode (two-terminal device, SMC/DO‑214 package).
Function: SM4T18CAY is a unidirectional TVS (transient-voltage‑suppressor) diode with an 18 V stand‑off class; it clamps and absorbs high‑energy transient overvoltages (ESD, lightning, surge/IEC 61000‑4‑5) to protect circuits and power rails. Typical rating: high peak pulse power (hundreds of watts) and fast response to transients.
Function: SM4T18CAY is a unidirectional TVS (transient-voltage‑suppressor) diode with an 18 V stand‑off class; it clamps and absorbs high‑energy transient overvoltages (ESD, lightning, surge/IEC 61000‑4‑5) to protect circuits and power rails. Typical rating: high peak pulse power (hundreds of watts) and fast response to transients.
Manufacturer
Manufacturer: Littelfuse, Inc.
What kind of company: An American multinational that designs and manufactures circuit protection and power-control components, including fuses, TVS diodes, ESD protectors, varistors, and related devices for electronics, automotive, and industrial applications.
What kind of company: An American multinational that designs and manufactures circuit protection and power-control components, including fuses, TVS diodes, ESD protectors, varistors, and related devices for electronics, automotive, and industrial applications.
Application
SM4T18CAY is a 4-channel TVS diode array with 18 V nominal standoff, used for ESD and transient protection on signal and power lines.
Typical applications:
- Automotive electronics (ECUs, sensors, CAN/LIN networks, infotainment)
- Industrial controls and I/O interfaces (RS-485, fieldbus, motor drives, power supplies)
- Consumer/telecom equipment with exposed connectors (USB, HDMI, telecom lines)
- Any 12–24 V system needing four-line protection with low capacitance to preserve high-speed signal integrity.
Typical applications:
- Automotive electronics (ECUs, sensors, CAN/LIN networks, infotainment)
- Industrial controls and I/O interfaces (RS-485, fieldbus, motor drives, power supplies)
- Consumer/telecom equipment with exposed connectors (USB, HDMI, telecom lines)
- Any 12–24 V system needing four-line protection with low capacitance to preserve high-speed signal integrity.
Package
6-pin SOT-23 package (SC-70-6).
