SMAJ54A

SMAJ54A is a unidirectional transient voltage suppressor (TVS) diode in the SMA (DO-214AC) package. It protects sensitive electronics from high-voltage transients on a ~54 V rail, commonly used in telecom, industrial, and automotive power circuits. The “A” suffix usually denotes unidirectional operation (a “B” variant would be bidirectional).
Key points:
- High peak pulse power capability (typical ~600 W for a 10/1000 μs pulse), suitable for absorbing brief surges.
- Stand-off voltage around 54 V; breakdown and clamping voltages are specified in the datasheet and depend on current.
- Quick response to overvoltage events, providing protection without slow reactions.
How to use:
- Place across the protected line to ground (unidirectional) or across the line (for bidirectional variants).
- Select Vwm just above the maximum normal operating voltage; verify Vr and Vclamp at the expected surge current (IPP).
- Ensure the package footprint and PCB layout minimize inductance and meet the device’s energy rating.
For exact electrical specs (Vr, Vclamp, IPP, capacitance), consult the SMAJ54A datasheet.

Here are the key features of SMAJ54A:
- Unidirectional TVS diode (suffix A) in SMA package (DO-214AC)
- Peak pulse power: up to 600 W (10/1000 µs)
- Reverse stand-off voltage (VRWM): 54 V
- Very fast response time (essentially instantaneous)
- Low leakage in normal operation
- Wide operating temperature: typically -55°C to +125°C
- Surface-mount, RoHS compliant
- Designed to protect power rails and data lines from surges and ESD
Note: Clamping voltage varies with surge current; refer to the datasheet for exact VCL vs. IPP curves.

It’s in the SMA package (DO-214AA), a surface-mount TVS diode.

- Pin count: 2 terminals (SMA package, two pins).
- Function: Surface-mount transient-voltage-suppressor (TVS) diode used to clamp voltage transients and protect circuits; 54 V stand-off (unidirectional version).

There isn’t a single exclusive manufacturer for SMAJ54A; it’s a standard TVS diode produced by several vendors, including Vishay Intertechnology and Littelfuse. Vishay Intertechnology is a global company that designs and manufactures semiconductors and passive electronic components.

SMAJ54A is a surface-mount TVS diode (unidirectional) for high‑energy transient suppression. It protects medium‑voltage DC rails and signal lines by clamping surges around 54 V. Typical applications include 48–54 V power rails, telecom and data interfaces (CAN, RS-485, Ethernet), automotive and industrial control electronics, power supplies and adapters, solar DC strings, and other equipment needing surge protection.

SMAJ54A is a 54V transient voltage suppressor diode in the SMA package. Common equivalents include:
- SMAJ54A (Littelfuse)
- SMBJ54A and SMBJ54CA (Vishay/ON Semiconductor) in the SMB package
- SMAJ54CA/SMBJ54CA for bidirectional versions
- Higher-power options: SMCJ54A or SM8S54A (same 54V rating in larger packages)
Note: cross-references depend on package, polarity, and power rating—verify datasheets for exact specs.