SN74LS688DWRIn StockTexas Instruments
The SN74LS688DWR is an 8-bit identity/magnitude comparator with enable input, featuring cascadable architecture and 45pF load capacitance. From $1.53, in stock worldwide shipping.
- Manufacturer
- Texas Instruments
- Package
- Small Outline Packages
- Pin Count
- 20
- Lifecycle
- ACTIVE
- Datasheet
- SN74LS688DWR Datasheet PDF
- Category
- Integrated Circuit
- Price
- From $1.5300(MOQ 1)
- Temp Range
- ?°C to 70.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- 8-bit identity comparator (P=Q) with active-low enable for easy bus expansion
- Cascadable design supports wider word comparisons without additional glue logic
- LS-family TTL with 24mA open-collector output drive and 45pF load capacitance
- Available in 20-pin SOIC (DWR) package for space-efficient PCB layouts
Applications
The SN74LS688DWR is widely used in address decoding and memory mapping circuits where microprocessors must compare address buses to predefined values. It is also applied in programmable logic controllers, industrial automation equipment, and data communication systems for identity checking and port selection. Its cascadable feature makes it ideal for building wide-word comparators in embedded control and digital signal processing applications.
Specifications
| Pbfree Code | Yes |
| YTEOL | 15 |
| Additional Feature | CASCADABLE |
| Family | LS |
| JESD-30 Code | R-PDSO-G20 |
| JESD-609 Code | e4 |
| Load Capacitance (CL) | 45pF |
| Logic IC Type | IDENTITY COMPARATOR |
| Max I(ol) | 0.024A |
| Number of Bits | 8 |
| Number of Functions | 8 |
| Output Characteristics | TOTEM-POLE |
| Output Polarity | INVERTED |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | SOP20,.4 |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Packing Method | TR |
| Peak Reflow Temperature (Cel) | 260 |
| Power Supply Current-Max (ICC) | 65mA |
| Prop. Delay@Nom-Sup | 23ns |
| Propagation Delay (tpd) | 23ns |
| Qualification Status | Not Qualified |
| Schmitt Trigger | YES |
| Supply Voltage-Max (Vsup) | 5.25V |
| Supply Voltage-Min (Vsup) | 4.85V |
| Supply Voltage-Nom (Vsup) | 5V |
| Surface Mount | YES |
| Technology | TTL |
| Temperature Grade | COMMERCIAL |
| Terminal Finish | Nickel/Palladium/Gold (Ni/Pd/Au) |
| Terminal Form | GULL WING |
| Terminal Pitch | 1.27mm |
| Terminal Position | DUAL |
| Time@Peak Reflow Temperature-Max (s) | 30 |
| Package | Small Outline Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.90 |
| Country of Origin | Malaysia |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for SN74LS688DWR:
Comparator, LS Series, 8-Bit, Inverted Output, TTL, PDSO20
Frequently Asked Questions
What is the SN74LS688DWR and what does it do?
The SN74LS688DWR is an 8-bit identity comparator IC from Texas Instruments. It compares two 8-bit words (P and Q) and asserts a low output when P equals Q. It includes an active-low enable pin for cascading multiple devices to support wider word comparisons in address decoding and bus matching applications.
What are the key electrical specifications of the SN74LS688DWR?
The SN74LS688DWR operates in the LS TTL logic family with a maximum output low current (I_OL) of 24mA, a load capacitance of 45pF, and is housed in a 20-pin SOIC package (JESD-30 code R-PDSO-G20). It is RoHS compliant (Pb-free, JESD-609 code e4) and has an estimated product life exceeding 15 years.
How do I cascade multiple SN74LS688DWR devices to compare more than 8 bits?
To cascade SN74LS688DWR devices for comparisons wider than 8 bits, connect the active-low enable output of one stage to the enable input of the next stage. When all lower-order bits match, the first stage enables the next, creating a ripple-enable chain. This cascadable architecture allows 16-bit, 24-bit, or wider comparisons with minimal additional components.
What packages are available for the SN74LS688DWR and what are alternatives?
The SN74LS688DWR is available in a 20-pin SOIC wide-body package (DWR suffix). Texas Instruments also offers this device in DIP and other surface-mount packages under the SN74LS688 family. Functional alternatives include the SN74HC688 (CMOS, lower power) and SN74ALS688 (advanced low-power Schottky) for designs requiring different power or speed characteristics.
Related Guides
Is Buying Electronic Components from Chinese Suppliers Safe? A 2025–2026 Buyer's Guide
A 2025–2026 buyer's guide to sourcing electronic components from Chinese suppliers: real risks, authorized vs. broker channels, and a 5-point safety framework.
Apr 22, 2026
BOM Optimization: How to Reduce Electronic Component Costs Without Sacrificing Quality
Practical strategies for reducing BOM costs by 15-30% through smart component selection, supplier diversification, and procurement optimization.
Apr 9, 2026
Top 10 Microcontrollers in 2025: A Comprehensive Comparison Guide
Detailed comparison of the most popular MCUs in 2025 — STM32, ESP32, RP2040, nRF52, and more. Specs, pricing, ecosystem, and use-case recommendations.
Apr 9, 2026
How to Read an IC Datasheet: A Practical Guide for Engineers
Master the art of reading IC datasheets. Learn what every section means, which specs matter most, and how to extract the information you need for your design.
Apr 9, 2026
Why Buy from FindMyChip
About Texas Instruments
Texas Instruments (TI) is a global semiconductor company headquartered in Dallas, Texas. TI designs and manufactures analog and embedded processing chips used in industrial, automotive, consumer, communications, and enterprise systems.
| Qty. | Unit Price | Ext. Price |
|---|---|---|
| 1+ | $2.3200 | $2.32 |
| 25+ | $1.7600 | $44.00 |
| 100+ | $1.6500 | $165.00 |
| 1000+ | $1.5300 | $1530.00 |
In Stock · 24h Response · Worldwide Shipping
Response within 24 hours · Worldwide shipping
“Their engineering team helped us find a pin-compatible alternative when our original MCU went EOL.”