Diodes Incorporated SMBJ20CA-13-F

Overview

SMBJ20CA-13-F from Diodes Incorporated is a bi-directional 600W transient voltage suppressor (TVS) diode in SMB package, with 20V reverse standoff voltage (VRWM), 22.2V minimum breakdown voltage (VBR), and 32.4V maximum clamping voltage (VC) at 18.5A peak pulse current (IPP); used for ESD and surge protection on DC power rails and data lines in industrial control systems.

For engineers reviewing the SMBJ20CA-13-F datasheet, SMBJ20CA-13-F pinout, SMBJ20CA-13-F application, or SMBJ20CA-13-F equivalent, key selection criteria include clamping voltage margin relative to protected IC VCC, peak pulse current handling under IEC 61000-4-5 8/20μs surges, thermal derating above +25°C, and bi-directional symmetry for AC-coupled or floating signal line protection.

Technical Context

This bi-directional TVS operates symmetrically across both polarities, enabling protection of AC signals or ungrounded interfaces without polarity constraints. Its glass-passivated junction ensures stable breakdown characteristics and low leakage (<5μA at VRWM) over temperature.

The device responds to transients within <1ns, clamping voltages below 32.4V at 18.5A (8/20μs waveform), and sustains 600W non-repetitive peak pulse power with 4.8W/°C derating above +25°C ambient - critical for sustained surge events in motor drives and power supplies.

Key Specifications

Pinout & Package

Package: SMB (Surface Mount Body), molded plastic case per UL 94V-0, 3.3–3.94mm length, 4.06–4.57mm width, 1.96–2.21mm height; terminals are matte tin-plated for RoHS-compliant solderability.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient suppression applications.

Compared with SMBJ20CA-13-F, Littelfuse's SMBJ20CA offers full form-fit-function equivalence, while ON Semi's P6SMB20CA trades 0.6V higher clamping and 0.3W/°C lower thermal derating for legacy qualification pedigree - making Diodes' version optimal for new designs prioritizing clamping precision and thermal margin.

Availability

SMBJ20CA-13-F is available at Aetrix Electronics and suitable for industrial motor drives, automotive body control modules, telecom power feeds, and medical diagnostic equipment requiring stable component supply across extended production lifecycles.

Supply support for SMBJ20CA-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 manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.

This device belongs to Diodes' SMBJ series of surface-mount TVS diodes, engineered specifically for high-reliability transient suppression in harsh environments - emphasizing low clamping voltage, tight VBR tolerance, and robust thermal performance.

FAQ

What is the maximum clamping voltage for SMBJ20CA-13-F at its rated peak pulse current?

The maximum clamping voltage (VC) is 32.4V at 18.5A peak pulse current (IPP), measured using an 8/20μs current waveform per IEC 61000-4-5. This value is guaranteed across the full operating temperature range (−55°C to +150°C) and defines the upper voltage limit imposed on protected circuitry during surge events.

Is SMBJ20CA-13-F suitable for protecting RS-485 communication lines?

Yes - its bi-directional architecture, 32.4V clamping voltage, and low capacitance (<100pF at 1MHz) make it appropriate for RS-485 bus protection. It should be placed between differential pair lines (A/B) and ground, with layout attention to minimize parasitic inductance to preserve sub-nanosecond response time.

How does the SMBJ20CA-13-F differ from the unidirectional SMBJ20A-13-F?

SMBJ20CA-13-F is bi-directional with symmetrical breakdown in both polarities and no cathode band marking; SMBJ20A-13-F is unidirectional, features a cathode band, and conducts only when cathode is positive relative to anode. Their VRWM, VBR, and VC values are identical, but CA variant supports AC or floating signal protection where polarity is undefined.

Does SMBJ20CA-13-F require derating at elevated ambient temperatures?

Yes - its peak pulse power must be derated linearly at 4.8W/°C above +25°C ambient, per the pulse derating curve in DS19002 Rev. 20-2. At +75°C ambient, maximum usable peak pulse power drops to 360W (600W − 4.8W/°C × 50°C), directly impacting survivability under repeated surge conditions.