Littelfuse Inc. SMDJ33CA - Semicone IC Supplier

Mfr	Littelfuse Inc.
Device Type	Bidirectional TVS Diode (Zener)
Series	SMDJ
Number of Channels	1 (Bidirectional)
Peak Pulse Power Dissipation (Max)	3000 W (3 kW)
Peak Pulse Current (Max)	56.3 A
Reverse Standoff Voltage	33 V (Max)
Breakdown Voltage	36.7 V (Min), 40.6 V (Max)
Clamping Voltage	53.3 V (Max)
Reverse Leakage Current	1 µA (Min) / 2 µA (Typ)
Forward Voltage	3.5 V
Power Dissipation	6.5 W
Operating Temperature	-65°C to +150°C
Package	DO-214AB (SMCJ)
Mounting Type	Surface Mount
Compliance	RoHS Compliant

The SMDJ33CA from Littelfuse is a 1500W peak pulse power transient voltage suppression (TVS) diode designed to provide bidirectional protection against voltage transients in 33V DC power lines and signal interfaces. Housed in the compact DO-214AB (SMC) surface-mount, this avalanche-mode TVS diode features a reverse standoff voltage of 33V, a breakdown voltage of 37.5V minimum, and a maximum clamping voltage of 77.9V at the peak pulse current of 19.3A. With a fast response time of less than 5ns and low incremental surge resistance, this 1500W TVS diode provides reliable protection for sensitive electronic equipment against ESD, induced lightning, and switching transients. The bidirectional configuration makes it ideal for protecting AC lines, DC rails of either polarity, and bidirectional data lines, while operating across the full -55°C to +150°C junction temperature range in RoHS-compliant, halogen-free construction.
Application Scenarios
The SMDJ33CA bidirectional TVS diode is deployed across multiple voltage-sensitive systems for surge and transient protection. Primary applications include protection of 24V DC industrial power supplies, PLC input/output modules, and motor drives against switching transients. In automotive systems, this TVS diode protects 12V/24V vehicle electrical systems, electronic control units, and battery management circuits from inductive load dumps and load transients. Additional deployments cover telecom line protection for PoE and DSL interfaces, security system sensors and panels, and renewable energy controllers where 33V-rated components interface with higher-voltage battery systems requiring bidirectional overvoltage protection.
Frequently Asked Questions
Q1: What is the difference between SMDJ33CA and SMDJ33A? The SMDJ33CA is the bidirectional version protecting against both positive and negative transients, while the SMDJ33A is the unidirectional version for DC-only protection with lower forward-clamping voltage.
Q2: How many TVS diodes are needed for AC power protection? For single-phase AC, two bidirectional SMDJ33CA devices (line-to-neutral and line/neutral-to-ground) provide complete protection; for DC rails, a single bidirectional unit at the supply input handles both polarity surges.
Alternative bidirectional diode Models
● SMCJ33CA: The lower-power 1500W SMCJ series alternative with the same 33V voltage rating in the identical SMC/DO-214AB package footprint.
● SMDJ30CA: The lower-voltage 30V variant for 28V DC applications requiring tighter clamping thresholds in the same package.
● SMDJ36CA: The higher-voltage 36V alternative for 30V DC systems with additional margin against supply fluctuation.
● SM8S33CA: The automotive-grade 5100W TVS from Vishay/Littelfuse for enhanced surge capability in vehicle electrical systems.