MAX489EPD RS422/RS485 Transceiver Equivalent & Substitute Parts

Part Overview

The MAX489EPD is a full-duplex RS422/RS485 transceiver IC in 14-DIP packaging manufactured by Analog Devices Inc./Maxim Integrated. This part is classified as obsolete, though 1,328 units remain in stock as new original inventory. The MAX489EPD operates as a 1/1 transceiver with a 250 kbps data rate and 70 mV receiver hysteresis, designed for industrial communication applications requiring robust noise immunity.

Due to its obsolete status, identifying active equivalent and substitute parts is essential for long-term design continuity and supply chain reliability. Equivalent parts maintain identical electrical and mechanical specifications, while manufacturer-recommended substitutes offer enhanced features or extended operating ranges within the same functional category.

Key Parameters

Parameter	Specification
Manufacturer Part Number	MAX489EPD
Manufacturer	Analog Devices Inc./Maxim Integrated
Type	Transceiver
Protocol	RS422, RS485
Number of Drivers/Receivers	1/1
Duplex	Full
Data Rate	250 kbps
Receiver Hysteresis	70 mV
Voltage - Supply	4.75V ~ 5.25V
Operating Temperature	-40°C ~ 85°C
Package / Case	14-DIP (0.300", 7.62mm)
Mounting Type	Through Hole
Product Status	Obsolete
RoHS Status	RoHS non-compliant

Substitute Part Grouping Explanation

Substitution eligibility for the MAX489EPD is determined by the following critical parameters:

Electrical Compatibility Requirements:

Protocol: RS422/RS485 full-duplex operation
Number of Drivers/Receivers: 1/1 configuration
Voltage Supply Range: 4.75V ~ 5.25V
Data Rate: 250 kbps minimum
Package / Case: 14-DIP (0.300", 7.62mm)
Mounting Type: Through Hole

Substitute Categories:

Parametric Equivalents maintain identical electrical specifications and differ only in product status (active vs. obsolete) and RoHS compliance:

MAX489EEPD+
MAX489EPD+

Manufacturer-Recommended Substitutes are approved alternatives that meet core electrical requirements but may vary in receiver hysteresis or operating temperature range:

LT1791ACN#PBF (20 mV hysteresis, 0°C ~ 70°C operating range)
LT1791HN#PBF (20 mV hysteresis, -40°C ~ 125°C operating range)
LT1791IN#PBF (20 mV hysteresis, -40°C ~ 85°C operating range)
LTC491IN#PBF (70 mV hysteresis, -40°C ~ 85°C operating range)

All substitutes maintain the same package, mounting type, supply voltage range, and protocol support as the original MAX489EPD.

Parameter Comparison

Part Number	Manufacturer	Product Status	Protocol	Drivers/Receivers	Data Rate	Receiver Hysteresis	Operating Temperature	Supply Voltage	Package	RoHS Status
MAX489EPD	Analog Devices/Maxim	Obsolete	RS422, RS485	1/1	250 kbps	70 mV	-40°C ~ 85°C	4.75V ~ 5.25V	14-DIP	Non-compliant
MAX489EEPD+	Analog Devices/Maxim	Active	RS422, RS485	1/1	250 kbps	70 mV	-40°C ~ 85°C	4.75V ~ 5.25V	14-DIP	ROHS3 Compliant
MAX489EPD+	Analog Devices/Maxim	Active	RS422, RS485	1/1	250 kbps	70 mV	-40°C ~ 85°C	4.75V ~ 5.25V	14-DIP	ROHS3 Compliant
LT1791ACN#PBF	Analog Devices	Active	RS422, RS485	1/1	250 kbps	20 mV	0°C ~ 70°C	4.75V ~ 5.25V	14-DIP	ROHS3 Compliant
LT1791HN#PBF	Analog Devices	Active	RS422, RS485	1/1	250 kbps	20 mV	-40°C ~ 125°C	4.75V ~ 5.25V	14-DIP	ROHS3 Compliant
LT1791IN#PBF	Analog Devices	Active	RS422, RS485	1/1	250 kbps	20 mV	-40°C ~ 85°C	4.75V ~ 5.25V	14-DIP	ROHS3 Compliant
LTC491IN#PBF	Analog Devices	Active	RS422, RS485	1/1	250 kbps	70 mV	-40°C ~ 85°C	4.75V ~ 5.25V	14-DIP	ROHS3 Compliant

Engineering Selection Recommendations

For Direct Replacement (Identical Specifications): MAX489EEPD+ and MAX489EPD+ are parametric equivalents to the MAX489EPD, maintaining 70 mV receiver hysteresis and -40°C ~ 85°C operating temperature. Both are active products with ROHS3 compliance, offering superior supply chain availability compared to the obsolete original part. MAX489EPD+ provides the highest inventory level (2,464 units) among equivalent options.

For Extended Temperature Range Applications: LT1791HN#PBF extends the upper operating temperature to 125°C while maintaining the same supply voltage and package specifications. This part is suitable for applications requiring enhanced thermal performance beyond the standard -40°C ~ 85°C range.

For Noise-Sensitive Applications: LT1791 series parts (LT1791ACN#PBF, LT1791HN#PBF, LT1791IN#PBF) feature 20 mV receiver hysteresis compared to the MAX489EPD's 70 mV, providing improved noise discrimination in electrically noisy environments. LT1791IN#PBF matches the original operating temperature range (-40°C ~ 85°C) while offering this enhanced specification.

For Matching Original Hysteresis Specification: LTC491IN#PBF maintains the 70 mV receiver hysteresis of the MAX489EPD with identical operating temperature range and supply voltage, offering an alternative from the LTC product line with active product status and ROHS3 compliance.

All recommended substitutes are manufactured by Analog Devices Inc., ensuring consistent quality and technical support standards.

Frequently Asked Questions (FAQ)

Q: Can MAX489EEPD+ and MAX489EPD+ be used interchangeably with MAX489EPD?

A: Yes. Both parts are parametric equivalents with identical electrical specifications: 1/1 transceiver configuration, RS422/RS485 protocol support, 250 kbps data rate, 70 mV receiver hysteresis, -40°C ~ 85°C operating temperature, and 14-DIP package. The primary differences are product status (active vs. obsolete) and RoHS compliance (ROHS3 vs. non-compliant).

Q: What is the difference between MAX489EPD+ and LT1791IN#PBF?

A: Both parts share identical operating temperature range (-40°C ~ 85°C), supply voltage (4.75V ~ 5.25V), and 14-DIP package. The key difference is receiver hysteresis: MAX489EPD+ has 70 mV while LT1791IN#PBF has 20 mV. Lower hysteresis provides better noise discrimination but may require cleaner signal conditioning in electrically noisy environments.

Q: Which substitute is best for industrial applications requiring extended temperature operation?

A: LT1791HN#PBF is rated for -40°C ~ 125°C, extending 40°C above the standard range. This part maintains all other specifications of the MAX489EPD while providing enhanced thermal capability for high-temperature industrial environments.

Q: Are all substitute parts RoHS compliant?

A: Yes. All listed substitute parts (MAX489EEPD+, MAX489EPD+, LT1791ACN#PBF, LT1791HN#PBF, LT1791IN#PBF, and LTC491IN#PBF) are ROHS3 compliant. The original MAX489EPD is RoHS non-compliant, making active substitutes preferable for new designs subject to RoHS regulations.

Q: Can LT1791 series parts replace MAX489EPD in existing designs without circuit modification?

A: LT1791 series parts are pin-compatible and functionally equivalent in 14-DIP package configuration. However, the reduced receiver hysteresis (20 mV vs. 70 mV) may affect noise immunity characteristics. Circuit validation is necessary if the original design relied on the 70 mV hysteresis specification for noise margin.

Q: What is the inventory status for each substitute?

A: MAX489EPD+ has the highest availability (2,464 units), followed by LTC491IN#PBF (2,200 units) and MAX489EEPD+ (963 units). LT1791HN#PBF has the lowest inventory (760 units). All parts are listed as new original stock.

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