74HC688PW,112 Equivalent & Substitute Parts

Part Overview

The 74HC688PW,112 is an 8-bit identity comparator manufactured by Nexperia USA Inc., designed for magnitude comparison applications with active-low output. This device is classified as obsolete, which necessitates identification of equivalent and substitute components for ongoing design support and procurement continuity. The 74HC688 series provides A=B output functionality in a 20-TSSOP surface-mount package, suitable for logic-level comparison operations across industrial and commercial applications.

Substiute Parts

74HC688PW,112

Nexperia USA Inc.In Stock: 105274HC688PW,112 Datasheet

Current PartRFQ

CD74HC688PWR

Texas InstrumentsIn Stock: 2903CD74HC688PWR Datasheet

UpgradeRFQ

CD74HC688PWT

Texas InstrumentsIn Stock: 1696CD74HC688PWT Datasheet

UpgradeRFQ

SN74HC688PWR

Texas InstrumentsIn Stock: 1913SN74HC688PWR Datasheet

SimilarRFQ

SN74HC688PWT

Texas InstrumentsIn Stock: 1254SN74HC688PWT Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74HC688PW,112 is determined by strict equivalence across the following critical parameters:

• 8-bit identity comparator architecture with A=B output function
• Active-low output configuration
• 20-TSSOP surface-mount package with identical pinout and mechanical dimensions
• Supply voltage range 2V ~ 6V
• Output current capability of 5.2mA (high and low)
• Quiescent current of 8 µA
• RoHS3 compliance and MSL Level 1 rating

Substitute parts are grouped into two categories based on product status and operational temperature range:

Upgrade Category (Active Status): CD74HC688PWR and CD74HC688PWT from Texas Instruments maintain full electrical equivalence with extended operating temperature range (-55°C ~ 125°C) and active product status.

Similar Category (Limited Availability): SN74HC688PWR and SN74HC688PWT from Texas Instruments provide functional equivalence with restricted operating temperature range (-40°C ~ 85°C) and discontinued or limited availability status.

Parameter Comparison

Engineering Selection Recommendations

For applications currently using the 74HC688PW,112, the following selection criteria apply based on product status and compliance:

Primary Selection: CD74HC688PWR is the recommended substitute. This part maintains active product status with Texas Instruments, provides extended operating temperature range (-55°C ~ 125°C), and delivers identical electrical performance with 29ns propagation delay. The part is available in Tape & Reel packaging and maintains full RoHS3 compliance and MSL Level 1 rating.

Secondary Selection: CD74HC688PWT provides equivalent electrical and thermal performance to CD74HC688PWR with identical specifications. This part is discontinued at DiGi Electronics but remains available through alternative distribution channels.

Alternative Selection: SN74HC688PWR is suitable for applications with operating temperature requirements limited to -40°C ~ 85°C. This part maintains active product status and is available in Cut Tape and Digi-Reel packaging formats. The propagation delay specification is 36ns at 6V with 50pF load, which represents a 7ns increase compared to the original part.

Restricted Selection: SN74HC688PWT is discontinued at DiGi Electronics and should be considered only when alternative sources are unavailable and application temperature range does not exceed -40°C ~ 85°C.

All substitute parts maintain RoHS3 compliance, MSL Level 1 rating, and identical 20-TSSOP package dimensions, ensuring direct mechanical and electrical compatibility with existing PCB designs.

Frequently Asked Questions (FAQ)

Q: Can CD74HC688PWR directly replace 74HC688PW,112 in existing designs?

A: Yes. CD74HC688PWR provides direct electrical and mechanical compatibility. Both parts feature identical 8-bit identity comparator architecture, A=B output function, active-low output configuration, 20-TSSOP package, and core electrical specifications including 5.2mA output current and 8 µA quiescent current. The extended operating temperature range of CD74HC688PWR (-55°C ~ 125°C) encompasses the original part's range (-40°C ~ 125°C), ensuring compatibility across all temperature conditions.

Q: What is the difference between CD74HC688PWR and SN74HC688PWR?

A: Both parts are 8-bit identity comparators from Texas Instruments with identical supply voltage, output current, and quiescent current specifications. The primary differences are: (1) propagation delay: CD74HC688PWR specifies 29ns while SN74HC688PWR specifies 36ns at 6V with 50pF load; (2) operating temperature range: CD74HC688PWR operates from -55°C ~ 125°C while SN74HC688PWR operates from -40°C ~ 85°C; (3) product status: CD74HC688PWR is active while SN74HC688PWR is discontinued at DiGi Electronics.

Q: Are the packaging formats interchangeable?

A: The 20-TSSOP package dimensions are identical across all substitute parts (0.173" width, 4.40mm). However, packaging formats differ: 74HC688PW,112 is supplied in Tube format, CD74HC688PWR and CD74HC688PWT are supplied in Tape & Reel, and SN74HC688PWR is supplied in Cut Tape and Digi-Reel formats. These format differences affect handling and automated assembly processes but do not impact electrical or mechanical compatibility on the PCB.

Q: Which substitute part should be selected for new designs?

A: CD74HC688PWR is the recommended selection for new designs. This part maintains active product status, provides the fastest propagation delay (29ns), supports the widest operating temperature range (-55°C ~ 125°C), and ensures long-term availability and supply continuity.

Q: Is the 7ns propagation delay difference between CD74HC688PWR and SN74HC688PWR significant?

A: The propagation delay difference (29ns versus 36ns) must be evaluated against specific application timing requirements. For applications with timing margins greater than 7ns, both parts are functionally equivalent. For timing-critical applications, CD74HC688PWR with 29ns propagation delay is the appropriate selection.

Q: Do all substitute parts maintain RoHS3 compliance?

A: Yes. All substitute parts listed (CD74HC688PWR, CD74HC688PWT, SN74HC688PWR, SN74HC688PWT) maintain RoHS3 compliance and MSL Level 1 rating, identical to the original 74HC688PW,112 part.