SFH6731 Equivalent & Substitute Parts

Part Overview

The SFH6731 is a 2-channel logic output optoisolator manufactured by Vishay Semiconductor Opto Division, featuring 5300Vrms isolation voltage and push-pull totem pole output configuration. This component is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production requirements. The SFH6731 operates at 5MBd data rate with 1kV/µs common mode transient immunity in an 8-DIP through-hole package.

Substiute Parts

SFH6731

Vishay Semiconductor Opto DivisionIn Stock: 1554SFH6731 Datasheet

Current PartRFQ

HCPL-2231

Broadcom LimitedIn Stock: 5818HCPL-2231 Datasheet

MFR RecommendedRFQ

HCPL-2430-020E

Broadcom LimitedIn Stock: 5772HCPL-2430-020E Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the SFH6731 is determined by the following critical parameters:

• Channel Configuration: 2 channels required
• Output Architecture: Push-pull, totem pole output mandatory
• Isolation Voltage: Minimum 3750Vrms acceptable; higher ratings provide enhanced margin
• Common Mode Transient Immunity: Minimum 1kV/µs required
• Package: 8-DIP (0.300", 7.62mm) through-hole form factor
• Operating Temperature Range: -40°C ~ 85°C
• Input Type: DC input configuration
• Current Output Capability: 25 mA per channel

Two substitute parts meet these criteria: HCPL-2231 and HCPL-2430-020E. Both are manufactured by Broadcom Limited and maintain active product status, addressing the obsolescence of the original SFH6731.

Parameter Comparison

Engineering Selection Recommendations

HCPL-2430-020E is the primary substitute for the SFH6731. This part maintains ROHS3 compliance matching the original component, provides isolation voltage within acceptable parameters at 5000Vrms, and delivers superior performance characteristics including 40MBd data rate and significantly reduced propagation delay (55ns versus 300ns). The HCPL-2430-020E operates within a narrower supply voltage range (4.75V ~ 5.25V) compared to the SFH6731 (4.5V ~ 15V), requiring circuit design verification for supply compatibility.

HCPL-2231 serves as an alternative substitute when supply voltage flexibility is required. This part maintains the original 5MBd data rate and 300ns propagation delay specifications, supporting supply voltages from 4.5V to 20V. However, HCPL-2231 is RoHS non-compliant and provides lower isolation voltage at 3750Vrms, suitable only for applications where isolation voltage margin is not critical and RoHS compliance is not mandated.

For new designs and production requiring RoHS3 compliance and high-reliability isolation, HCPL-2430-020E is the recommended selection. For legacy system maintenance where supply voltage range and RoHS non-compliance are acceptable, HCPL-2231 provides functional equivalence.

Frequently Asked Questions (FAQ)

Q: Can HCPL-2231 directly replace SFH6731 in all applications?

A: HCPL-2231 meets the core functional requirements of 2-channel push-pull output, 1kV/µs CMTI, and 8-DIP package compatibility. However, the lower isolation voltage (3750Vrms versus 5300Vrms) and RoHS non-compliance status require application-specific evaluation. Use HCPL-2231 only when isolation voltage margin is not critical and RoHS compliance is not required.

Q: What are the supply voltage implications when switching to HCPL-2430-020E?

A: HCPL-2430-020E operates within 4.75V ~ 5.25V, a narrower range than SFH6731 (4.5V ~ 15V). Circuits designed for the SFH6731 with supply voltages below 4.75V or above 5.25V require redesign or alternative part selection. Verify supply voltage stability and regulation before implementation.

Q: Does HCPL-2430-020E provide performance advantages over SFH6731?

A: Yes. HCPL-2430-020E delivers 40MBd data rate (8× faster than SFH6731's 5MBd), propagation delay of 55ns (versus 300ns), and faster rise/fall times. These improvements enable higher-speed signal transmission and reduced timing uncertainty in digital isolation applications.

Q: Are all three parts pin-compatible?

A: Yes. SFH6731, HCPL-2231, and HCPL-2430-020E share identical 8-DIP (0.300", 7.62mm) package geometry and through-hole mounting configuration, enabling direct PCB footprint compatibility without layout modification.

Q: Which substitute part maintains the best compliance profile?

A: HCPL-2430-020E maintains ROHS3 compliance, matching the original SFH6731. HCPL-2231 is RoHS non-compliant. For regulated industries and modern manufacturing standards, HCPL-2430-020E is the compliance-aligned selection.