TLP621-4BL Equivalent & Substitute Parts

Part Overview

The TLP621-4BL is a quad-channel optoisolator with transistor output manufactured by Isocom Components 2004 LTD. This 16-DIP through-hole component provides 5300Vrms isolation voltage and is designed for applications requiring galvanic isolation between input and output circuits. The part is currently active in production with 785 units in stock. Alternative models may be required due to inventory constraints, application-specific timing requirements, or supply chain considerations.

Substiute Parts

TLP621-4BL

Isocom Components 2004 LTDIn Stock: 883TLP621-4BL Datasheet

Current PartRFQ

ISP521-4X

Isocom Components 2004 LTDIn Stock: 2080ISP521-4X Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

The ISP521-4X qualifies as a parametric equivalent to the TLP621-4BL based on the following critical substitution criteria:

• Number of Channels: Both parts feature 4 isolated channels
• Isolation Voltage: Both rated at 5300Vrms
• Current Transfer Ratio: Identical minimum (50% @ 5mA) and maximum (600% @ 5mA) specifications
• Output Configuration: Both provide transistor output with 55V maximum output voltage and 50mA per-channel current rating
• Package Type: Both use 16-DIP (0.300", 7.62mm) through-hole mounting
• Operating Temperature Range: Both operate from -30°C to 100°C
• Electrical Characteristics: Matching Vf (1.15V typical), If (50mA maximum), and Vce saturation (400mV maximum)
• Compliance: Both are ROHS3 compliant with MSL 1 rating

Parameter Comparison

Engineering Selection Recommendations

Both the TLP621-4BL and ISP521-4X are active production parts from Isocom Components 2004 LTD with identical isolation voltage, channel configuration, and output specifications. Selection between these parts should be based on the following factors:

TLP621-4BL is the primary choice when the specified rise/fall time of 2µs and 3µs is a critical design requirement, as this part provides the faster rise time specification.

ISP521-4X is suitable for applications where the rise time specification of 4µs is acceptable. This part offers higher inventory availability (2000 units versus 785 units) and identical compliance certifications (ROHS3, MSL 1). Both parts are pin-compatible and functionally equivalent for standard isolation applications within the specified electrical parameters.

Both parts maintain identical maximum output voltage (55V), per-channel current rating (50mA), and operating temperature range (-30°C to 100°C), ensuring direct substitution capability in through-hole PCB designs.

Frequently Asked Questions (FAQ)

Q: Can ISP521-4X be used as a direct replacement for TLP621-4BL in existing designs?

A: Yes, the ISP521-4X is a direct pin-compatible replacement. Both parts use the 16-DIP package with identical pinout and electrical ratings for isolation voltage, output voltage, and current capacity. The primary difference is the rise time specification (4µs versus 2µs).

Q: What is the difference in timing performance between these parts?

A: The TLP621-4BL specifies a rise time of 2µs and fall time of 3µs. The ISP521-4X specifies a rise time of 4µs and fall time of 3µs. Applications requiring faster rise time transitions should use the TLP621-4BL. For applications with less stringent timing requirements, the ISP521-4X is functionally equivalent.

Q: Are both parts RoHS compliant?

A: Yes, both the TLP621-4BL and ISP521-4X are ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity level, suitable for standard manufacturing and storage conditions.

Q: Do these parts have the same isolation voltage rating?

A: Yes, both parts provide 5300Vrms isolation voltage with identical current transfer ratio specifications (50% minimum to 600% maximum at 5mA input current).

Q: Which part should be selected for new designs?

A: For new designs, either part is acceptable based on timing requirements. The ISP521-4X offers higher inventory availability. If the application requires the faster 2µs rise time, the TLP621-4BL should be specified.