Diodes Incorporated SMBJ48CA-13-F

Overview

SMBJ48CA-13-F from Diodes Incorporated is a bi-directional 600W surface-mount transient voltage suppressor (TVS) with 48V reverse standoff voltage, 53.3V minimum breakdown voltage at 1mA, 77.4V maximum clamping voltage at 7.7A peak pulse current, and SMB package. It protects DC power rails and data lines in industrial control systems against ESD, lightning-induced surges, and switching transients.

For engineers reviewing the SMBJ48CA-13-F datasheet, SMBJ48CA-13-F pinout, SMBJ48CA-13-F application, or SMBJ48CA-13-F equivalent, key selection criteria include clamping voltage margin relative to system operating voltage, peak pulse current capability under 8.3ms waveform, bi-directional symmetry for AC-coupled or floating signal paths, and RoHS-compliant matte tin termination for lead-free reflow compatibility.

Technical Context

This TVS diode operates as a voltage-clamped shunt protector: during overvoltage events exceeding VRWM = 48V, it avalanches to divert surge current away from downstream circuitry while limiting voltage across protected nodes to ≤77.4V. Its glass-passivated die ensures stable breakdown characteristics and low leakage (<5µA at 48V).

The bi-directional configuration enables symmetrical clamping on both polarities-critical for protecting AC interfaces, RS-485 buses, or ungrounded sensor inputs-without requiring polarity-aware layout. Thermal derating follows 4.8W/°C above +25°C ambient, with junction temperature rated from –55°C to +150°C.

Key Specifications

Pinout & Package

Package: SMB (Surface Mount Body), molded plastic case per UL 94V-0, 0.1g mass, matte tin-plated terminals solderable per MIL-STD-202 Method 208.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bi-directional TVS applications.

Compared with SMBJ48CA-13-F, SMBJ48CA-T lacks documented RoHS compliance and traceable lead-free plating, while SMCJ48CA-13-F trades compactness for enhanced energy handling-making the original optimal for space-constrained 48V industrial interfaces needing certified green manufacturing.

Availability

SMBJ48CA-13-F is available at Aetrix Electronics and suitable for industrial PLC I/O modules, 48V DC power distribution systems, RS-485 communication ports, and automotive body control modules requiring stable component supply across multi-year production cycles.

Supply support for SMBJ48CA-13-F 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

Diodes Incorporated is a global semiconductor company specializing in discrete, analog, and mixed-signal solutions, with design centers in Asia, Europe, and the US, serving industrial, computing, and communications markets.

This device belongs to the SMBJ series of transient voltage suppressors, engineered specifically for high-reliability surge protection in harsh electromagnetic environments-emphasizing stable clamping, low leakage, and consistent response across temperature extremes.

FAQ

What does the 'C' in SMBJ48CA-13-F signify?

The 'C' denotes bi-directional functionality, meaning the device clamps overvoltage transients equally in both polarities-essential for protecting AC-coupled signals, differential buses like RS-485, or floating sensor inputs without polarity constraints. This differs from uni-directional variants (e.g., SMBJ48A) which only protect against positive-going surges relative to ground.

Can SMBJ48CA-13-F replace SMBJ48A in an existing design?

No-SMBJ48A is uni-directional and requires correct cathode orientation to function; substituting the bi-directional SMBJ48CA-13-F eliminates polarity sensitivity but alters leakage behavior and clamping symmetry. If the original design relies on directional blocking (e.g., reverse-polarity protection), replacement requires validation of system-level surge response and DC bias stability.

What is the maximum allowable PCB trace length between SMBJ48CA-13-F and the protected node?

Trace inductance directly impacts clamping effectiveness: for 8.3ms surges, keep total loop inductance below 10nH. With typical 0.2mm trace width and 0.2mm spacing, this limits distance to ≤8mm from TVS to protected IC pin and return path. Use dedicated ground planes and minimize via count to preserve low-inductance shunt path.

How does SMBJ48CA-13-F perform under repeated surge stress?

It is rated for non-repetitive pulses only (max 4 pulses/minute per datasheet Note 6); repeated exposure degrades clamping voltage and increases leakage. For repetitive threats, add upstream current-limiting resistors or use hybrid protection (e.g., polymer PTC + TVS) to ensure long-term reliability without parameter shift.