ISP521-4G Equivalent & Substitute Parts

Part Overview

The ISP521-4G 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 DC input applications requiring galvanic isolation with transistor-based switching outputs. The part is currently active in production with ROHS3 compliance and unlimited moisture sensitivity rating. Substitute parts are identified based on matching electrical specifications, isolation voltage, channel configuration, output characteristics, and package format to ensure direct functional equivalence in circuit applications.

Key Parameters

Parameter	Value
Manufacturer Part Number	ISP521-4G
Manufacturer	Isocom Components 2004 LTD
Category	Optoisolators
Number of Channels	4
Voltage - Isolation	5300Vrms
Current Transfer Ratio (Min)	50% @ 5mA
Current Transfer Ratio (Max)	600% @ 5mA
Rise / Fall Time (Typ)	4µs, 3µs
Input Type	DC
Output Type	Transistor
Voltage - Output (Max)	55V
Current - Output / Channel	50mA
Voltage - Forward (Vf) (Typ)	1.15V
Current - DC Forward (If) (Max)	50 mA
Vce Saturation (Max)	400mV
Operating Temperature	-30°C ~ 100°C
Package / Case	16-DIP (0.400", 10.16mm)
Mounting Type	Through Hole
RoHS Status	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)
REACH Status	REACH Unaffected

Substitute Part Grouping Explanation

Substitute parts for the ISP521-4G are qualified based on the following critical parameters that determine functional equivalence:

Isolation Voltage: 5300Vrms (all substitutes match)
Number of Channels: 4 channels (all substitutes match)
Output Type: Transistor output (all substitutes match)
Package Format: 16-DIP through-hole (all substitutes match)
Current Transfer Ratio Range: 50% to 600% @ 5mA (all substitutes match)
Rise / Fall Time: 4µs / 3µs typical (all substitutes match)
Output Voltage Rating: 55V maximum (all substitutes match)
Output Current per Channel: 50mA (all substitutes match)
Vce Saturation: 400mV maximum (all substitutes match)
Operating Temperature Range: -30°C to 100°C (all substitutes match)
Input Type: DC (all substitutes match)
Compliance: ROHS3 Compliant, REACH Unaffected (all substitutes match)

All identified substitute parts maintain identical electrical and mechanical specifications, enabling direct replacement in applications requiring quad-channel optoisolation with transistor switching outputs.

Parameter Comparison

Parameter	ISP521-4G	ISP521-4XG	ISP621-4XG	ISP621-4XGR	ISP621-4XGRG	TLP521-4XG
Manufacturer	Isocom	Isocom	Isocom	Isocom	Isocom	Isocom
Number of Channels	4	4	4	4	4	4
Voltage - Isolation	5300Vrms	5300Vrms	5300Vrms	5300Vrms	5300Vrms	5300Vrms
Current Transfer Ratio (Min)	50% @ 5mA	50% @ 5mA	50% @ 5mA	50% @ 5mA	50% @ 5mA	50% @ 5mA
Current Transfer Ratio (Max)	600% @ 5mA	600% @ 5mA	600% @ 5mA	600% @ 5mA	600% @ 5mA	600% @ 5mA
Rise / Fall Time (Typ)	4µs, 3µs	4µs, 3µs	4µs, 3µs	4µs, 3µs	4µs, 3µs	4µs, 3µs
Output Type	Transistor	Transistor	Transistor	Transistor	Transistor	Transistor
Voltage - Output (Max)	55V	55V	55V	55V	55V	55V
Current - Output / Channel	50mA	50mA	50mA	50mA	50mA	50mA
Voltage - Forward (Vf) (Typ)	1.15V	1.15V	1.15V	1.15V	1.15V	1.15V
Current - DC Forward (If) (Max)	50 mA	50 mA	50 mA	50 mA	50 mA	50 mA
Vce Saturation (Max)	400mV	400mV	400mV	400mV	400mV	400mV
Operating Temperature	-30°C ~ 100°C	-30°C ~ 100°C	-30°C ~ 100°C	-30°C ~ 100°C	-30°C ~ 100°C	-30°C ~ 100°C
Package / Case	16-DIP (0.400", 10.16mm)	16-DIP (0.400", 10.16mm)	16-DIP (0.400", 10.16mm)	16-DIP (0.400", 10.16mm)	16-DIP (0.400", 10.16mm)	16-DIP (0.400", 10.16mm)
Mounting Type	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
REACH Status	REACH Unaffected	REACH Unaffected	REACH Unaffected	REACH Unaffected	REACH Unaffected	REACH Unaffected
Inventory Status	970 Pcs New Original	948 Pcs New Original	935 Pcs New Original	875 Pcs New Original	631 Pcs New Original	1171 Pcs New Original

Engineering Selection Recommendations

All substitute parts listed maintain full electrical and mechanical equivalence to the ISP521-4G. Selection among these alternatives should be based on:

Product Status: All parts are active in production, ensuring ongoing availability and support.

Compliance Certifications: All substitute parts carry ROHS3 compliance and REACH unaffected status, meeting current environmental and regulatory requirements equivalent to the main part.

Packaging and Mounting: All parts utilize identical 16-DIP through-hole packaging (0.400", 10.16mm), enabling direct PCB footprint compatibility without layout modifications.

Inventory Availability: TLP521-4XG offers the highest current stock level at 1171 pieces, followed by ISP521-4G at 970 pieces. ISP621-4XGRG has the lowest inventory at 631 pieces.

Series Designation: ISP521-4XG maintains the same series as the main part (ISP521-4), while ISP621-4XG, ISP621-4XGR, and ISP621-4XGRG belong to the ISP621-4 series. TLP521-4XG belongs to the TLP521-4 series. All series variants meet identical performance specifications.

Frequently Asked Questions (FAQ)

Q: Can ISP521-4XG be used as a direct replacement for ISP521-4G?

A: Yes. ISP521-4XG is a parametric equivalent with identical electrical specifications, isolation voltage, channel configuration, output characteristics, and 16-DIP package format. Direct substitution is supported without circuit modifications.

Q: What is the difference between ISP521-4 series and ISP621-4 series parts?

A: Both series maintain identical electrical and mechanical specifications as provided in the parameter comparison table. The series designation reflects internal manufacturing or product line categorization but does not affect functional equivalence or performance characteristics.

Q: Are all substitute parts suitable for the same operating temperature range?

A: Yes. All substitute parts operate across the identical temperature range of -30°C to 100°C, matching the ISP521-4G specification.

Q: Do substitute parts maintain the same isolation voltage rating?

A: Yes. All substitute parts provide 5300Vrms isolation voltage, identical to the ISP521-4G.

Q: Can these parts be used interchangeably on the same PCB?

A: Yes. All substitute parts use the 16-DIP through-hole package format with identical pin spacing (0.400", 10.16mm), enabling direct PCB footprint compatibility without layout changes.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All substitute parts carry ROHS3 compliance and REACH unaffected status, meeting current environmental regulations.

Q: What is the maximum output current per channel for all these parts?

A: All parts, including substitutes, support 50mA maximum output current per channel with 55V maximum output voltage rating.

Q: Do substitute parts have the same current transfer ratio specifications?

A: Yes. All substitute parts maintain the identical current transfer ratio range of 50% to 600% @ 5mA, with matching rise and fall times of 4µs and 3µs respectively.

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