SN75C185N Equivalent & Substitute Parts

Part Overview

The SN75C185N is a full-duplex RS232 transceiver manufactured by Texas Instruments, featuring 3 drivers and 5 receivers in a 20-pin DIP package. This component is classified as Last Time Buy, indicating discontinued production with limited inventory availability. The SN75C185N operates across a wide supply voltage range of 4.5V to 13.2V and is designed for through-hole mounting applications. Due to its Last Time Buy status, identifying functionally equivalent substitute parts is essential for ongoing design support and production continuity.

Substiute Parts

SN75C185N

Texas InstrumentsIn Stock: 4509SN75C185N Datasheet

Current PartRFQ

SN75185DBR

Texas InstrumentsIn Stock: 2914SN75185DBR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN75C185N is determined by the following critical parameters:

• Protocol Compatibility: Both main and substitute parts must implement RS232 transceiver functionality
• Driver/Receiver Configuration: The 3/5 driver/receiver count must be maintained for pin-compatible operation
• Supply Voltage Range: The substitute must operate within the application's supply voltage requirements
• Operating Temperature Range: The substitute must support the specified temperature range (0°C ~ 70°C minimum)
• Compliance Standards: RoHS3 compliance and REACH unaffected status must be maintained

The SN75185DBR qualifies as a manufacturer-recommended substitute based on identical protocol, driver/receiver configuration, and compliance certifications. However, differences in mounting type, package form factor, and supply voltage range require careful evaluation for specific applications.

Parameter Comparison

Engineering Selection Recommendations

The SN75185DBR is the manufacturer-recommended substitute for the SN75C185N and maintains active product status, ensuring continued availability and support. Both components are ROHS3 compliant and REACH unaffected, meeting current regulatory requirements.

Selection between these parts depends on application constraints:

SN75C185N is appropriate for through-hole PCB designs requiring wide supply voltage operation (up to 13.2V) and higher receiver hysteresis (1.1V) for noise immunity in electrically noisy environments.

SN75185DBR is appropriate for surface-mount PCB designs operating within standard 5V supply rails and where compact form factor is required. The reduced receiver hysteresis (500 mV) is suitable for applications with controlled signal integrity.

Both parts share identical RS232 protocol implementation, driver/receiver configuration, and operating temperature range, ensuring functional equivalence within their respective mounting and voltage constraints.

Frequently Asked Questions (FAQ)

Q: Can the SN75185DBR directly replace the SN75C185N in an existing through-hole design?

A: No. The SN75185DBR is a surface-mount component in 20-SSOP package, while the SN75C185N uses through-hole 20-DIP package. PCB redesign is required for mounting compatibility.

Q: What is the impact of the reduced supply voltage range in the SN75185DBR?

A: The SN75185DBR operates from 4.5V to 5.5V, compared to the SN75C185N's 4.5V to 13.2V range. Applications requiring supply voltages above 5.5V cannot use the SN75185DBR without voltage regulation.

Q: Are the receiver hysteresis differences significant for substitution?

A: The SN75C185N features 1.1V hysteresis while the SN75185DBR has 500 mV hysteresis. The SN75C185N provides greater noise immunity in high-noise environments. The SN75185DBR is suitable for controlled signal integrity applications.

Q: Do both parts meet current compliance requirements?

A: Yes. Both the SN75C185N and SN75185DBR are ROHS3 compliant and REACH unaffected, meeting current regulatory standards.

Q: Why is the SN75C185N marked as Last Time Buy?

A: Last Time Buy status indicates the manufacturer has discontinued production. Existing inventory is available for final orders, but long-term availability is not guaranteed. The SN75185DBR, with Active status, is the recommended path for new designs.