TVS Diode for 24VDC Industrial Input Protection

Question

Problem: TVS Diode for 24VDC Industrial Input Protection. Solve this hands-on electronics task on EWskills.

Accepted Answer

1. Component Purpose

Industrial 24VDC bus lines pick up fast transient spikes from motors, solenoids, and contactors. A unidirectional TVS diode across the power input clamps these spikes to a safe level.

Standoff voltage of 27–30V is above normal bus voltage (24V +10% = 26.4V) but ensures clamping stays ≤50V to protect downstream components.

Required: Unidirectional · Vstandoff 27–30V · Vclamp ≤50V · ≥400W · SMA · Littelfuse

2. How to Find It on DigiKey

Go to DigiKey.com → Circuit Protection → TVS - TVS Diodes

Apply these filters:

Unidirectional Channels → 1
Voltage - Reverse Standoff (Typ) → 27V to 30V range
Power - Peak Pulse → 400W or higher
Package / Case → SMA
Manufacturer → Littelfuse Inc.
Part Status → Active

Tip: Unidirectional TVS is correct for DC power rails — it clamps positive surges and conducts like a normal diode in reverse. Bidirectional would waste headroom on the unused polarity.

3. Key Specifications & What They Mean

Specification	Required	Why
Direction	Unidirectional	DC rail; single-polarity surges.
Standoff Voltage	27–30V	Above 24V+10%; below 50V clamp limit.
Clamping Voltage	≤50V	Protects downstream 50V-rated parts.
Peak Pulse Power	≥400W	Industrial surge levels.
Package	SMA	Standard power TVS package.
Manufacturer	Littelfuse	Company AVL requirement.
Temp Range	−55°C to +125°C	Industrial conditions.
RoHS	Yes	Compliance required.

4. Selecting a Safe, Production-Ready Part

The filtered list will show matching parts. Before you pick one, check: Is it Active? Is stock available? Is the manufacturer reputable? Is a datasheet available?

Full checklist: How to Select a Safe, Production-Ready Component — EWskills Guide

5. Filtered DigiKey Link

➡ View Matching Parts — Littelfuse, Unidirectional TVS, 27–30V, ≥400W, SMA

29. TVS Diode for 24VDC Industrial Input Protection