ISL8490IP RS422/RS485 Transceiver Equivalent & Substitute Parts

Part Overview

The ISL8490IP is a 1/1 full-duplex RS422/RS485 transceiver manufactured by Renesas Electronics Corporation in an 8-DIP package. This component is classified as obsolete, which necessitates identification of active equivalent parts for new designs and ongoing system support. The ISL8490IP operates across industrial temperature ranges (-40°C to 85°C) with a 5 Mbps data rate capability, making it suitable for industrial communication applications requiring robust serial interface functionality.

Substiute Parts

ISL8490IP

Renesas Electronics CorporationIn Stock: 15359ISL8490IP Datasheet

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ADM488ANZ

Analog Devices Inc.In Stock: 797ADM488ANZ Datasheet

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LTC490CN8#PBF

Analog Devices Inc.In Stock: 2149LTC490CN8#PBF Datasheet

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LTC490IN8#PBF

Analog Devices Inc.In Stock: 3772LTC490IN8#PBF Datasheet

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MAX490CPA+

Analog Devices Inc./Maxim IntegratedIn Stock: 4744MAX490CPA+ Datasheet

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MAX490EPA+

Analog Devices Inc./Maxim IntegratedIn Stock: 15123MAX490EPA+ Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the ISL8490IP is determined by strict alignment of the following electrical and mechanical parameters:

Critical Matching Parameters:

• Protocol: RS422/RS485 full-duplex operation
• Configuration: 1/1 driver/receiver architecture
• Receiver Hysteresis: 70 mV
• Package: 8-DIP (0.300", 7.62mm)
• Mounting Type: Through Hole
• Supply Voltage Range: Compatibility within 4.5V ~ 5.5V envelope

Acceptable Variation Parameters:

• Data Rate: Substitute parts may operate at lower data rates (250 kbps minimum) while maintaining full backward compatibility
• Operating Temperature: Substitute parts must support at least the -40°C ~ 85°C range or a subset thereof
• Supply Voltage: Substitute parts with narrower ranges (4.75V ~ 5.25V) remain compatible with standard 5V supply designs
• Product Status: Active parts are preferred over obsolete parts for new procurement

All identified substitute parts maintain identical package geometry, pin configuration, and core RS422/RS485 transceiver functionality, ensuring direct replacement capability in existing PCB layouts.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: MAX490EPA+

The MAX490EPA+ is the optimal substitute for the ISL8490IP based on the following criteria:

• Active product status with continuous manufacturer support and availability
• Full parameter alignment: identical 1/1 RS422/RS485 transceiver configuration, 70 mV receiver hysteresis, and 8-DIP package
• Operating temperature range (-40°C ~ 85°C) matches the original specification exactly
• ROHS3 compliance satisfies modern regulatory requirements
• Data rate of 2.5 Mbps remains suitable for industrial RS422/RS485 applications
• Supply voltage range (4.75V ~ 5.25V) is compatible with standard 5V supply designs

Secondary Recommendation: LTC490IN8#PBF

The LTC490IN8#PBF provides an alternative with identical temperature range coverage (-40°C ~ 85°C) and active product status. This part is suitable when supply voltage tolerance of 4.75V ~ 5.25V is acceptable for the application.

Conditional Recommendation: LTC490CN8#PBF

The LTC490CN8#PBF is suitable only for applications operating within the 0°C ~ 70°C temperature range. This part is not recommended for systems requiring full industrial temperature coverage (-40°C ~ 85°C).

Not Recommended: ADM488ANZ

The ADM488ANZ operates at 250 kbps data rate, which is significantly lower than the ISL8490IP specification (5 Mbps). This part is suitable only for low-speed RS422/RS485 applications and should not be used as a direct replacement for the ISL8490IP in systems requiring higher data rates.

Frequently Asked Questions (FAQ)

Q: Can MAX490EPA+ be used as a direct replacement for ISL8490IP in existing designs?

A: Yes. The MAX490EPA+ maintains identical pin configuration, package geometry (8-DIP), and core RS422/RS485 transceiver functionality. No PCB modifications are required for substitution.

Q: What is the primary reason the ISL8490IP requires substitution?

A: The ISL8490IP is classified as obsolete. Active substitute parts ensure continued availability, manufacturer support, and compliance with current regulatory standards (ROHS3).

Q: Are there temperature-related constraints when selecting a substitute?

A: Yes. The LTC490CN8#PBF and MAX490CPA+ operate only within 0°C ~ 70°C. These parts are not suitable for applications requiring the full industrial range (-40°C ~ 85°C). The MAX490EPA+ and LTC490IN8#PBF support the complete temperature range.

Q: Does the data rate difference between ISL8490IP (5 Mbps) and substitute parts affect compatibility?

A: Substitute parts with lower data rates (MAX490EPA+ at 2.5 Mbps, ADM488ANZ at 250 kbps) remain fully compatible with RS422/RS485 systems. Lower data rate capability does not prevent operation at reduced speeds. However, ADM488ANZ is not recommended for applications requiring 5 Mbps operation.

Q: What is the significance of the 70 mV receiver hysteresis specification?

A: The 70 mV receiver hysteresis is a critical parameter for RS422/RS485 signal integrity. All identified substitute parts maintain this specification, ensuring equivalent noise immunity and signal detection characteristics.

Q: Are there supply voltage considerations when substituting parts?

A: The ISL8490IP accepts 4.5V ~ 5.5V. Substitute parts with narrower ranges (4.75V ~ 5.25V) remain compatible with standard 5V supply designs. Systems operating at the extremes of the original range (below 4.75V or above 5.25V) should use MAX490EPA+ or LTC490IN8#PBF to maintain full compatibility.

Q: What does ROHS3 compliance mean for component selection?

A: ROHS3 compliance indicates the part meets current Restriction of Hazardous Substances regulations. All active substitute parts are ROHS3 compliant, whereas the obsolete ISL8490IP is RoHS non-compliant. This is relevant for applications subject to environmental and regulatory requirements.