SN65LBC170DW Equivalent & Substitute Parts

Part Overview

The SN65LBC170DW is a 3/3 transceiver half-duplex interface IC manufactured by Texas Instruments, designed for RS422 and RS485 communication protocols. This device operates at 4.75V to 5.25V supply voltage with a maximum data rate of 30Mbps and is housed in a 20-SOIC surface mount package. The product is currently classified as obsolete, making identification of equivalent and substitute parts essential for ongoing system support and new design implementations.

Substiute Parts

SN65LBC170DW

Texas InstrumentsIn Stock: 2202SN65LBC170DW Datasheet

Current PartRFQ

SN65C1167ENSR

Texas InstrumentsIn Stock: 9568SN65C1167ENSR Datasheet

MFR RecommendedRFQ

SN65LBC171DW

Texas InstrumentsIn Stock: 879SN65LBC171DW Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the SN65LBC170DW is determined by the following critical parameters:

Primary Substitution Criteria:

• Protocol compatibility (RS422, RS485)
• Number of drivers/receivers (3/3 configuration)
• Duplex mode (Half-duplex operation)
• Data rate capability (30Mbps minimum)
• Supply voltage range (4.75V ~ 5.25V)
• Operating temperature range (-40°C ~ 85°C)
• Package compatibility (20-SOIC form factor)

Substitute Categories:

1. Parametric Equivalent: SN65LBC171DW matches all electrical and mechanical specifications of the main part, including identical driver/receiver configuration, duplex mode, data rate, voltage range, temperature range, and package type. This part is a direct functional replacement.

2. Functional Substitute (with Design Considerations): SN65C1167ENSR provides RS422/RS485 transceiver functionality but differs in configuration (2/2 drivers/receivers versus 3/3), duplex mode (full-duplex versus half-duplex), package size (16-SOIC versus 20-SOIC), and receiver hysteresis (60 mV versus 40 mV). This part requires circuit redesign evaluation.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Recommended): SN65LBC171DW is the parametric equivalent and primary choice for replacing SN65LBC170DW. Both parts are obsolete but maintain identical electrical specifications, driver/receiver configuration, duplex operation, and package form factor. This substitution requires no circuit redesign and provides pin-for-pin compatibility. Both parts are ROHS3 compliant with MSL rating of 1.

For Active Product Requirement: If procurement of an active (non-obsolete) product is mandatory, SN65C1167ENSR is available from Texas Instruments with active product status. However, this part introduces design changes: reduced driver/receiver count (2/2 versus 3/3), full-duplex operation (versus half-duplex), smaller package footprint (16-SOIC versus 20-SOIC), and increased receiver hysteresis (60 mV versus 40 mV). Implementation of this substitute requires circuit evaluation and potential PCB layout modification. The supply voltage range is broader (4.5V ~ 5.5V), providing improved flexibility. All parts maintain ROHS3 compliance and MSL rating of 1.

Frequently Asked Questions (FAQ)

Q: Can SN65LBC171DW be used as a direct replacement for SN65LBC170DW? A: Yes. SN65LBC171DW is a parametric equivalent with identical electrical and mechanical specifications. No circuit redesign is required. Both parts are obsolete but functionally interchangeable.

Q: What are the key differences between SN65LBC170DW and SN65C1167ENSR? A: The primary differences are: (1) driver/receiver configuration—SN65LBC170DW has 3/3 versus SN65C1167ENSR's 2/2; (2) duplex mode—SN65LBC170DW operates half-duplex versus SN65C1167ENSR's full-duplex; (3) package size—SN65LBC170DW uses 20-SOIC versus SN65C1167ENSR's 16-SOIC; (4) receiver hysteresis—SN65LBC170DW has 40 mV versus SN65C1167ENSR's 60 mV. These differences require circuit evaluation before substitution.

Q: Is SN65C1167ENSR suitable for applications requiring half-duplex operation? A: SN65C1167ENSR is designed for full-duplex operation. While it supports RS422 and RS485 protocols, its full-duplex configuration differs from the half-duplex operation of SN65LBC170DW. Application requirements must be evaluated to determine compatibility.

Q: What is the impact of the different receiver hysteresis values? A: SN65LBC170DW has 40 mV receiver hysteresis while SN65C1167ENSR has 60 mV. Higher hysteresis reduces sensitivity to noise but may affect signal detection in low-amplitude applications. System noise margins and signal characteristics must be evaluated.

Q: Can the 16-SOIC package of SN65C1167ENSR fit into a 20-SOIC footprint? A: No. The 16-SOIC package (0.209", 5.30mm width) is physically smaller than the 20-SOIC package (0.295", 7.50mm width). PCB layout modification is required for this substitution.

Q: Are all three parts RoHS compliant? A: Yes. SN65LBC170DW, SN65LBC171DW, and SN65C1167ENSR are all ROHS3 compliant with MSL rating of 1 (unlimited moisture sensitivity level).

Q: Which part should be selected for new designs? A: SN65C1167ENSR is the only active product and is recommended for new designs. However, application requirements for driver/receiver count, duplex mode, and package size must be confirmed before selection. For legacy system support, SN65LBC171DW provides parametric equivalence to the original SN65LBC170DW.