SN75C189N Equivalent & Substitute Parts

Part Overview

The SN75C189N is a 0/4 Receiver RS232 interface IC manufactured by Texas Instruments in a 14-PDIP package. This component functions as an RS232 receiver for serial communication applications requiring signal level conversion from RS232 standard levels to TTL/CMOS logic levels.

The SN75C189N carries a Last Time Buy product status, indicating that Texas Instruments has discontinued active production. This status necessitates identification of equivalent substitute components to ensure design continuity and procurement availability for ongoing production requirements.

Substiute Parts

SN75C189N

Texas InstrumentsIn Stock: 4364SN75C189N Datasheet

Current PartRFQ

SN75C189AN

Texas InstrumentsIn Stock: 1679SN75C189AN Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SN75C189N is determined by the following critical parameters:

Mandatory Matching Parameters:

• Protocol: RS232
• Number of Drivers/Receivers: 0/4
• Package / Case: 14-DIP (0.300", 7.62mm)
• Mounting Type: Through Hole
• Voltage - Supply: 4.5V ~ 6V
• Operating Temperature Range: 0°C ~ 70°C

Allowable Variation:

• Receiver Hysteresis: The SN75C189N specifies 330 mV. Substitute parts may operate with different hysteresis values provided they remain within RS232 specification tolerances and do not compromise signal integrity in the target application.

The SN75C189AN meets all mandatory matching parameters and qualifies as a direct substitute. Both components share identical electrical specifications for supply voltage, operating temperature, package configuration, and RS232 protocol implementation. The difference in receiver hysteresis (970 mV versus 330 mV) reflects manufacturing tolerance variations within the RS232 standard and does not preclude functional equivalence.

Parameter Comparison

Engineering Selection Recommendations

The SN75C189AN is the qualified substitute for the SN75C189N based on the following criteria:

Product Status Alignment: The SN75C189AN maintains Active product status with Texas Instruments, ensuring continued availability and manufacturing support. This addresses the procurement risk associated with the SN75C189N's Last Time Buy designation.

Compliance Certification: Both components maintain identical RoHS3 compliance and REACH unaffected status, satisfying regulatory requirements for equivalent component selection.

Electrical and Mechanical Compatibility: The SN75C189AN provides identical electrical specifications across supply voltage, operating temperature range, and RS232 protocol implementation. The 14-DIP through-hole package ensures direct mechanical compatibility with existing PCB designs without layout modification.

Functional Equivalence: Both components implement the same receiver architecture with four RS232 input channels. The variation in receiver hysteresis reflects standard manufacturing tolerance within RS232 specifications and does not impact functional performance in standard serial communication applications.

Frequently Asked Questions (FAQ)

Q: Can the SN75C189AN be used as a direct replacement for the SN75C189N without PCB modification?

A: Yes. Both components use the 14-DIP through-hole package with identical pinout and electrical specifications. No PCB layout changes are required for substitution.

Q: What is the significance of the different receiver hysteresis values (330 mV vs. 970 mV)?

A: Receiver hysteresis defines the voltage differential between the rising and falling threshold levels for RS232 signal detection. Both values fall within RS232 standard tolerances. The SN75C189AN's higher hysteresis may provide improved noise immunity in electrically noisy environments, while the SN75C189N's lower hysteresis offers faster response to marginal signal transitions.

Q: Are there any supply voltage or temperature range differences between these components?

A: No. Both components operate identically across the 4.5V to 6V supply range and 0°C to 70°C temperature range.

Q: Why is the SN75C189N designated as Last Time Buy?

A: Last Time Buy status indicates that Texas Instruments has concluded active production of this component. Existing inventory may be available through authorized distributors, but long-term procurement should transition to the SN75C189AN to ensure supply continuity.

Q: Do both components meet the same regulatory compliance standards?

A: Yes. Both the SN75C189N and SN75C189AN are ROHS3 compliant and REACH unaffected, meeting identical regulatory requirements for electronic component use.