HCPL-4731#500 Equivalent & Substitute Parts

Part Overview

The HCPL-4731#500 is a 2-channel optoisolator with Darlington output, rated for 3750Vrms isolation voltage. Manufactured by Broadcom Limited, this component is designed for applications requiring high-voltage isolation with dual-channel switching capability. The part is currently discontinued at DiGi Electronics, necessitating identification of equivalent and substitute components for ongoing design support and procurement.

Substiute Parts

HCPL-4731#500

Broadcom LimitedIn Stock: 1126HCPL-4731#500 Datasheet

Current PartRFQ

HCPL-4731-500E

Broadcom LimitedIn Stock: 1110HCPL-4731-500E Datasheet

Parametric EquivalentRFQ

HCPL2730S

Fairchild SemiconductorIn Stock: 2300HCPL2730S Datasheet

MFR RecommendedRFQ

HCPL2730SD

onsemiIn Stock: 4478HCPL2730SD Datasheet

MFR RecommendedRFQ

HCPL2731S

onsemiIn Stock: 1131HCPL2731S Datasheet

MFR RecommendedRFQ

HCPL2731SD

onsemiIn Stock: 3156HCPL2731SD Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the HCPL-4731#500 is determined by the following critical parameters:

Primary Substitution Criteria:

• Number of Channels: 2 (required)
• Output Type: Darlington (required)
• Package / Case: 8-SMD, Gull Wing (required)
• Voltage - Isolation: 3750Vrms or higher (required for equivalent isolation performance)
• Current - Output / Channel: 60mA minimum (required)
• Voltage - Output (Max): 18V or higher (required for output voltage compatibility)

Secondary Compatibility Factors:

• Current Transfer Ratio: Minimum 600% @ 500µA or equivalent performance at specified input current
• Operating Temperature range compatibility with application requirements
• RoHS and regulatory compliance status

Substitute parts are grouped into two categories:

1. Parametric Equivalent (Full Isolation Match): HCPL-4731-500E maintains identical isolation voltage (3750Vrms), current transfer ratio range, and output voltage specifications. This part is a direct functional replacement with improved product status (Active vs. Discontinued).

2. Functional Substitutes (Reduced Isolation Voltage): HCPL2730S, HCPL2730SD, HCPL2731S, and HCPL2731SD operate at 2500Vrms isolation voltage. These parts are suitable for applications where the full 3750Vrms isolation is not required, but maintain the 2-channel Darlington output configuration, 60mA output current, and 8-SMD Gull Wing package.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: HCPL-4731-500E

The HCPL-4731-500E is the direct parametric equivalent to the HCPL-4731#500. It maintains identical electrical specifications including 3750Vrms isolation voltage, 600-8000% current transfer ratio range, 18V maximum output voltage, and 60mA output current per channel. The component is currently Active in product status, ensuring ongoing availability and supply chain continuity. HCPL-4731-500E is ROHS3 compliant, addressing regulatory requirements where the original part does not. The packaging format (8-SMD, Gull Wing) and thermal operating range (0°C ~ 70°C) are identical, enabling direct board-level substitution without design modification.

Secondary Recommendations: HCPL2731S and HCPL2731SD

For applications where 3750Vrms isolation is not a design requirement, HCPL2731S and HCPL2731SD provide functional substitution at 2500Vrms isolation voltage. Both parts maintain the 18V maximum output voltage and 60mA output current specifications, ensuring compatibility with output stage designs. HCPL2731SD is available in Cut Tape & Digi-Reel packaging with higher inventory (3100 Pcs). Both parts are ROHS3 compliant and feature extended operating temperature range (-40°C ~ 85°C), providing broader environmental compatibility than the original part. Current transfer ratio is specified at 500% @ 1.6mA, with faster switching times (300ns turn-on, 5µs turn-off) compared to the original part.

Alternative Consideration: HCPL2730S and HCPL2730SD

HCPL2730S and HCPL2730SD operate at 2500Vrms isolation with reduced maximum output voltage (7V vs. 18V). These parts are suitable only for applications where output voltage does not exceed 7V. Current transfer ratio is lower (300% @ 1.6mA). HCPL2730S is manufactured by Fairchild Semiconductor with higher inventory availability (2200 Pcs). HCPL2730SD is manufactured by onsemi with the highest inventory level (4400 Pcs) but is marked Obsolete in product status.

Frequently Asked Questions (FAQ)

Q: Can HCPL-4731-500E be used as a direct replacement for HCPL-4731#500?

A: Yes. HCPL-4731-500E is a parametric equivalent with identical isolation voltage (3750Vrms), current transfer ratio specifications, output voltage (18V max), and output current (60mA). The 8-SMD Gull Wing package and operating temperature range are identical. HCPL-4731-500E is currently Active in product status, whereas the original part is Discontinued at DiGi Electronics.

Q: What is the key difference between HCPL2731S/HCPL2731SD and HCPL2730S/HCPL2730SD?

A: The primary difference is maximum output voltage. HCPL2731 series supports 18V maximum output voltage, matching the original HCPL-4731#500 specification. HCPL2730 series is limited to 7V maximum output voltage. Both series operate at 2500Vrms isolation voltage. Current transfer ratio also differs: HCPL2731 series specifies 500% @ 1.6mA minimum, while HCPL2730 series specifies 300% @ 1.6mA minimum.

Q: Can I use HCPL2730S or HCPL2730SD if my application requires 18V output voltage?

A: No. HCPL2730S and HCPL2730SD are rated for maximum 7V output voltage. Using these parts in applications requiring 18V output would exceed component ratings and result in device failure or unreliable operation. HCPL2731S or HCPL2731SD must be used for 18V output compatibility.

Q: What is the isolation voltage difference between the original part and the HCPL2730/HCPL2731 series?

A: The original HCPL-4731#500 provides 3750Vrms isolation voltage. HCPL2730 and HCPL2731 series provide 2500Vrms isolation voltage. The 1250Vrms difference must be evaluated against application isolation requirements. If the design specifies 3750Vrms isolation as a mandatory requirement, only HCPL-4731-500E is suitable.

Q: Are all substitute parts RoHS compliant?

A: HCPL-4731-500E, HCPL2730SD, HCPL2731S, and HCPL2731SD are ROHS3 compliant. HCPL2730S does not specify RoHS status in available documentation. The original HCPL-4731#500 is RoHS non-compliant.

Q: What are the switching time differences between substitute parts?

A: The original HCPL-4731#500 specifies 3µs turn-on and 34µs turn-off time. HCPL-4731-500E maintains identical timing. HCPL2730S, HCPL2730SD, HCPL2731S, and HCPL2731SD all specify 300ns turn-on and 5µs turn-off time, representing significantly faster switching performance.

Q: Which substitute part has the highest inventory availability?

A: HCPL2730SD (onsemi) has the highest inventory with 4400 Pcs available. However, this part is marked Obsolete in product status. For Active status parts, HCPL2730S (Fairchild Semiconductor) has 2200 Pcs available, and HCPL-4731-500E (Broadcom Limited) has 1044 Pcs available.

Q: Can I use HCPL2731SD as a drop-in replacement for HCPL-4731#500?

A: HCPL2731SD is mechanically and functionally compatible (same 8-SMD Gull Wing package, 2 channels, Darlington output, 18V max output, 60mA output current). However, it operates at 2500Vrms isolation versus 3750Vrms for the original part. Substitution is valid only if the application does not require the full 3750Vrms isolation specification. HCPL2731SD is marked Obsolete in product status.