4N49A Optoisolator Equivalent & Substitute Parts

Part Overview

The 4N49A is an optoisolator transistor with base output manufactured by TT Electronics/Optek Technology. This component provides 1000VDC isolation with a single channel transistor output configuration in a TO-78-6 metal can package. The device is currently in active production status with 808 units in stock. Alternative equivalent parts may be required due to inventory availability, compliance requirements, or specific application constraints.

Substiute Parts

4N49A

TT Electronics/Optek TechnologyIn Stock: 8254N49A Datasheet

Current PartRFQ

JANTX4N49A

TT Electronics/Optek TechnologyIn Stock: 10442JANTX4N49A Datasheet

Parametric EquivalentRFQ

4N49TX

TT Electronics/Optek TechnologyIn Stock: 8034N49TX Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 4N49A is determined by the following critical parameters:

• Voltage - Isolation: 1000VDC (exact match required)
• Number of Channels: 1 (exact match required)
• Output Type: Transistor with Base (exact match required)
• Current Transfer Ratio: 200% minimum @ 1mA (exact match required)
• Package / Case: TO-78-6 Metal Can (exact match required)
• Voltage - Output (Max): 40V (exact match required)
• Current - Output / Channel: 50mA (exact match required)
• Vce Saturation (Max): 300mV (exact match required)
• Operating Temperature: -55°C ~ 125°C (exact match required)

Substitute parts must maintain identical electrical and mechanical specifications across all these parameters to ensure functional compatibility in the 4N49A application circuit.

Parameter Comparison

Engineering Selection Recommendations

JANTX4N49A is the primary equivalent substitute for the 4N49A. Both parts maintain identical electrical specifications and are ROHS3 compliant with active product status. The JANTX4N49A exhibits improved rise and fall time performance (20µs maximum versus 25µs typical) and maintains higher inventory availability (10400 units in stock).

The 4N49TX is electrically equivalent but carries obsolete product status and does not meet ROHS3 compliance requirements. Selection of 4N49TX should be limited to legacy system maintenance where RoHS compliance is not mandated and component availability from existing stock is prioritized.

Frequently Asked Questions (FAQ)

Q: Can JANTX4N49A directly replace 4N49A in new designs? A: Yes. JANTX4N49A meets all electrical and mechanical specifications of the 4N49A and maintains ROHS3 compliance for new product development.

Q: What is the difference between 4N49A and JANTX4N49A? A: Both parts are electrically identical with matching isolation voltage, current transfer ratio, output specifications, and operating temperature range. JANTX4N49A offers faster rise and fall time performance (20µs maximum) and higher inventory availability.

Q: Is 4N49TX suitable for new applications? A: No. The 4N49TX is obsolete and does not meet ROHS3 compliance. Use only for replacement in existing systems where RoHS compliance is not required.

Q: Are all substitute parts in the same TO-78-6 package? A: Yes. All listed equivalents use the TO-78-6 metal can package with identical pinout and mechanical dimensions.

Q: What are the critical parameters for substitution? A: Isolation voltage (1000VDC), channel count (1), output type (transistor with base), current transfer ratio (200-1000% @ 1mA), maximum output voltage (40V), output current (50mA), and package type (TO-78-6) must remain unchanged for functional compatibility.