SN74ALS640B-1DWG4 Texas Instruments Integrated Circuit (Small Outline Packages) In Stock
SN74ALS640B-1DWG4 is an octal bidirectional inverting bus transceiver by Texas Instruments in the ALS logic family, featuring 3-state outputs and direction control in a 20-pin wide SOIC package. Key specs: 8-bit bidirectional inverted data transfer, 48mA output sink current, 50pF load capacitance. Available in stock with worldwide shipping.
- Manufacturer
- Texas Instruments
- Package
- Small Outline Packages
- Pin Count
- 20
- Lifecycle
- OBSOLETE
- Datasheet
- SN74ALS640B-1DWG4 Datasheet PDF
- Category
- Integrated Circuit
- Temp Range
- ?°C to 70.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- Octal (8-bit) bidirectional inverting bus transceiver with 3-state outputs
- ALS bipolar logic family providing TTL-compatible high-speed operation from 5V supply
- 48mA output sink current (I(ol)) for driving heavily loaded backplane and bus lines
- Direction control and active-low output enable for flexible bus arbitration
- 20-pin wide SOIC (DW) package with RoHS-compliant lead-free finish
Applications
The SN74ALS640B-1DWG4 is used in CPU data bus interfaces, memory system buffers, and backplane communication where bidirectional 8-bit data transfer with signal inversion is required. Its high 48mA drive current and 3-state capability make it ideal for multi-master bus systems, address/data demultiplexing, and board-to-board interconnects in industrial computing and telecommunications.
Specifications
| YTEOL | 0 |
| Additional Feature | WITH DIRECTION CONTROL |
| Control Type | COMMON CONTROL |
| Count Direction | BIDIRECTIONAL |
| Family | ALS |
| JESD-30 Code | R-PDSO-G20 |
| JESD-609 Code | e4 |
| Load Capacitance (CL) | 50pF |
| Logic IC Type | BUS TRANSCEIVER |
| Max I(ol) | 0.048A |
| Number of Bits | 8 |
| Number of Functions | 1 |
| Number of Ports | 2 |
| Output Characteristics | 3-STATE |
| Output Polarity | INVERTED |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | SOP20,.4 |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Packing Method | TUBE |
| Peak Reflow Temperature (Cel) | 260 |
| Power Supply Current-Max (ICC) | 55mA |
| Prop. Delay@Nom-Sup | 11ns |
| Propagation Delay (tpd) | 10ns |
| Qualification Status | Not Qualified |
| Supply Voltage-Max (Vsup) | 5.5V |
| Supply Voltage-Min (Vsup) | 4.5V |
| Supply Voltage-Nom (Vsup) | 5V |
| Surface Mount | YES |
| Technology | TTL |
| Temperature Grade | COMMERCIAL |
| Terminal Finish | NICKEL PALLADIUM GOLD |
| 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 |
| HTS Code | 8542.39.00.60 |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for SN74ALS640B-1DWG4:
Rochester Electronics LLC ALS SERIES, 8-BIT TRANSCEIVER, INVERTED OUTPUT, PDSO20, GREEN, PLASTIC, SOP-20
Frequently Asked Questions
What does the SN74ALS640B-1DWG4 do and how does it differ from the SN74ALS245?
The SN74ALS640B-1DWG4 is an inverting bus transceiver, meaning it inverts the data logic level during transmission in either direction, unlike the SN74ALS245 which passes data non-inverted. The -1 speed suffix indicates a faster propagation delay variant, and its 48mA output sink current is double that of some competing devices, enabling heavier bus loading.
What is the output drive capability of the SN74ALS640B-1DWG4?
The SN74ALS640B-1DWG4 provides a maximum output sink current (I(ol)) of 48mA per output channel, which is among the highest available in standard TTL-compatible logic families. This high drive strength is suitable for driving long traces, multiple parallel receiver inputs, and terminated transmission line environments in industrial and computing backplane applications.
What package is the SN74ALS640B-1DWG4 available in?
The SN74ALS640B-1DWG4 is housed in a 20-pin wide-body SOIC (DW) package with JESD-30 code R-PDSO-G20, suitable for surface-mount PCB assembly. The G4 suffix indicates lead-free, RoHS-compliant packaging per JESD-609 code e4, supporting modern environmentally conscious manufacturing requirements.
Is the SN74ALS640B-1DWG4 suitable for backplane applications?
Yes, the SN74ALS640B-1DWG4 is specifically designed for high-drive bus applications including backplane interfaces. Its 48mA sink current handles the low impedance of terminated backplane buses, while its 3-state outputs and direction control allow multiple boards to share the same physical bus without conflict in multi-master system architectures.
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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.
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