ROV20H681K Equivalent & Substitute Parts

Part Overview

The ROV20H681K is a 680 V, 10 kA disc varistor manufactured by Littelfuse, designed for transient voltage suppression in through-hole applications. This component is classified as obsolete, making equivalent substitute parts necessary for ongoing design support and procurement. The varistor provides overvoltage protection across a wide operating temperature range of -40°C to 125°C and is RoHS3 compliant.

Substiute Parts

ROV20H681K

LittelfuseIn Stock: 1210ROV20H681K Datasheet

Current PartRFQ

B72220S0421K101

EPCOS - TDK ElectronicsIn Stock: 4780B72220S0421K101 Datasheet

MFR RecommendedRFQ

ERZ-V20D681

Panasonic Electronic ComponentsIn Stock: 1530ERZ-V20D681 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the ROV20H681K are qualified based on the following electrical and mechanical parameters:

• Varistor voltage range: 612 V (Min) to 748 V (Max) — ensures voltage clamping compatibility
• Mounting type: Through Hole — maintains PCB assembly compatibility
• Package form: Disc configuration — ensures mechanical fit in existing designs
• Maximum AC/DC voltage ratings: 420 V AC / 560 V DC — maintains system protection levels
• RoHS3 compliance and REACH unaffected status — ensures regulatory alignment

Substitute parts may vary in surge current capacity (7.5 kA to 10 kA) and energy dissipation (175 J to 430 J), which are application-dependent parameters. Package dimensions may differ slightly (20mm to 22.50mm disc) while maintaining through-hole compatibility.

Parameter Comparison

Engineering Selection Recommendations

Both substitute parts maintain the core electrical specifications required for 680 V transient voltage suppression. Selection between alternatives depends on application-specific surge current and energy dissipation requirements:

B72220S0421K101 (EPCOS - TDK Electronics) is an active product with MFR recommended status, offering 8 kA surge capacity and 175 J energy rating. This substitute is suitable for applications with moderate transient energy levels and provides the advantage of active product status with ongoing manufacturer support.

ERZ-V20D681 (Panasonic Electronic Components) is an active product in the ZNR® series, rated for 7.5 kA surge capacity and 382 J energy dissipation. This substitute provides higher energy handling than the EPCOS alternative while maintaining voltage compatibility. The package dimension is 22.50mm disc, requiring verification of PCB layout clearance.

Both substitutes are RoHS3 compliant and REACH unaffected, ensuring regulatory compliance equivalent to the original part.

Frequently Asked Questions (FAQ)

Q: Can B72220S0421K101 replace ROV20H681K in all applications?

A: B72220S0421K101 is electrically compatible for voltage clamping (680 V nominal). However, the surge current rating is 8 kA versus the original 10 kA. Applications experiencing surge currents exceeding 8 kA require evaluation of the energy dissipation profile (175 J) against system transient specifications.

Q: What is the impact of the package dimension difference in ERZ-V20D681?

A: ERZ-V20D681 uses a 22.50mm disc package versus the 20mm disc in the original part. Both are through-hole mounted and mechanically compatible with standard PCB layouts. Verify PCB footprint clearance and lead spacing before implementation.

Q: Are all three parts suitable for the same operating temperature range?

A: The original ROV20H681K operates from -40°C to 125°C. B72220S0421K101 operates from -40°C to 105°C, and ERZ-V20D681 operates from -40°C to 85°C. Applications requiring operation above 85°C must use the original part or B72220S0421K101.

Q: Do substitute parts maintain the same capacitance characteristics?

A: Capacitance values are provided at 1 kHz: ROV20H681K at 550 pF, B72220S0421K101 at 550 pF, and ERZ-V20D681 at 650 pF. Applications sensitive to capacitive loading should account for the 100 pF difference in the Panasonic substitute.

Q: What is the inventory status of substitute parts?

A: B72220S0421K101 has 4718 pcs in stock, and ERZ-V20D681 has 1500 pcs in stock, compared to 1151 pcs of the original ROV20H681K. Both substitutes offer improved availability for procurement planning.