HMHA281R3V Optoisolator Equivalent & Substitute Parts

Part Overview

The HMHA281R3V is a high-voltage optoisolator with transistor output manufactured by onsemi, designed for galvanic isolation applications requiring 3750Vrms isolation voltage. This component features a single channel configuration with 4-Mini-Flat surface mount packaging. The part is currently classified as obsolete, making identification of active equivalent alternatives essential for ongoing design support and procurement continuity.

Key Parameters

Parameter	Value
Manufacturer	onsemi
Category	Optoisolators
Number of Channels	1
Voltage - Isolation	3750Vrms
Current Transfer Ratio (Min)	50% @ 5mA
Current Transfer Ratio (Max)	600% @ 5mA
Output Type	Transistor
Voltage - Output (Max)	80V
Current - Output / Channel	50mA
Vce Saturation (Max)	400mV
Operating Temperature	-55°C ~ 100°C
Mounting Type	Surface Mount
Package / Case	4-SOIC (0.173", 4.40mm Width)
Moisture Sensitivity Level (MSL)	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution of the HMHA281R3V is determined by strict equivalence across the following critical parameters:

Voltage - Isolation: 3750Vrms (all substitutes maintain identical isolation rating)
Number of Channels: 1 (single channel configuration)
Output Type: Transistor (consistent output topology)
Current Transfer Ratio range: 50% to 600% @ 5mA (identical CTR specifications)
Voltage - Output (Max): 80V (maximum output voltage capability)
Current - Output / Channel: 50mA (output current rating)
Vce Saturation (Max): 400mV (saturation voltage specification)
Operating Temperature: -55°C ~ 100°C (thermal operating range)
Package / Case: 4-SOIC (0.173", 4.40mm Width) (mechanical and electrical footprint)
Rise / Fall Time: 3µs, 3µs (switching characteristics)

All identified substitutes maintain identical electrical and mechanical specifications across these parameters, ensuring direct functional equivalence.

Parameter Comparison

Parameter	HMHA281R3V	HMHA281R2	HMHA281R2V	HMHA281R4
Manufacturer	onsemi	onsemi	onsemi	onsemi
Product Status	Obsolete	Active	Active	Active
Number of Channels	1	1	1	1
Voltage - Isolation	3750Vrms	3750Vrms	3750Vrms	3750Vrms
Current Transfer Ratio (Min)	50% @ 5mA	50% @ 5mA	50% @ 5mA	50% @ 5mA
Current Transfer Ratio (Max)	600% @ 5mA	600% @ 5mA	600% @ 5mA	600% @ 5mA
Output Type	Transistor	Transistor	Transistor	Transistor
Voltage - Output (Max)	80V	80V	80V	80V
Current - Output / Channel	50mA	50mA	50mA	50mA
Vce Saturation (Max)	400mV	400mV	400mV	400mV
Operating Temperature	-55°C ~ 100°C	-55°C ~ 100°C	-55°C ~ 100°C	-55°C ~ 100°C
Mounting Type	Surface Mount	Surface Mount	Surface Mount	Surface Mount
Package / Case	4-SOIC (0.173", 4.40mm Width)	4-SOIC (0.173", 4.40mm Width)	4-SOIC (0.173", 4.40mm Width)	4-SOIC (0.173", 4.40mm Width)
Rise / Fall Time (Typ)	3µs, 3µs	3µs, 3µs	3µs, 3µs	3µs, 3µs
Moisture Sensitivity Level (MSL)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)
REACH Status	REACH Unaffected	REACH Unaffected	REACH Unaffected	REACH Unaffected
ECCN	EAR99	EAR99	EAR99	EAR99

Engineering Selection Recommendations

The HMHA281R3V is obsolete and should be replaced with one of the three active alternatives: HMHA281R2, HMHA281R2V, or HMHA281R4. All three substitutes maintain identical electrical and mechanical specifications, ensuring direct functional compatibility.

HMHA281R2 and HMHA281R2V are preferred selections due to higher inventory availability (18,100 and 19,100 units respectively) and active product status. Both are ROHS3 compliant, providing enhanced environmental and regulatory compliance compared to the obsolete original part.

HMHA281R4 remains an active alternative with 829 units in stock and ROHS3 compliance, suitable for applications where the other substitutes are unavailable.

All three substitutes are classified as REACH Unaffected and carry EAR99 export classification, maintaining regulatory equivalence with the original part.

Frequently Asked Questions (FAQ)

Q: Can HMHA281R2, HMHA281R2V, and HMHA281R4 be used interchangeably with HMHA281R3V?

A: Yes. All three substitutes maintain identical electrical parameters including isolation voltage (3750Vrms), current transfer ratio (50% to 600% @ 5mA), output voltage (80V max), output current (50mA), and operating temperature range (-55°C to 100°C). The 4-SOIC package footprint is identical across all parts, enabling direct PCB-level substitution.

Q: What is the difference between HMHA281R2 and HMHA281R2V?

A: Both parts are parametrically equivalent with identical electrical specifications and package configuration. The primary distinction is packaging format: HMHA281R2 is supplied in Tape & Reel (TR), while HMHA281R2V is also supplied in Tape & Reel (TR). Both are active products with ROHS3 compliance and high inventory availability.

Q: Why is HMHA281R3V classified as obsolete?

A: The HMHA281R3V has been discontinued by onsemi. The active alternatives (HMHA281R2, HMHA281R2V, and HMHA281R4) provide identical functionality and are recommended for all new designs and ongoing procurement.

Q: Are there any compliance differences between the obsolete part and the substitutes?

A: The substitutes HMHA281R2, HMHA281R2V, and HMHA281R4 are ROHS3 compliant, whereas the obsolete HMHA281R3V does not carry this certification. All parts maintain REACH Unaffected status and EAR99 export classification.

Q: What inventory considerations should guide part selection?

A: HMHA281R2V offers the highest inventory level at 19,100 units, followed by HMHA281R2 at 18,100 units. HMHA281R4 has lower availability at 829 units. For high-volume procurement, HMHA281R2V or HMHA281R2 are recommended.

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