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Texas Instruments SN74ACT240DBR
- Part No.:
- SN74ACT240DBR
- Manufacturer:
- Texas Instruments
- Package:
- 20-SSOP (0.209", 5.30mm Width)
- Datasheet:
-
SN74ACT240DBR.pdf
- Description:
- IC BUFF INVERT 5.5V 20SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,853
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Product details
Overview
SN74ACT240DBR from Texas Instruments is an octal 3-state inverting buffer/driver IC designed for bus-oriented data transmission, clock distribution, and memory address driving in industrial and consumer systems. It operates from 4.5 V to 5.5 V, delivers ≤8.5 ns propagation delay at 5 V, supports TTL-compatible inputs up to 5.5 V, and features balanced CMOS push-pull outputs capable of ±24 mA drive per channel.
For engineers reviewing the SN74ACT240DBR datasheet, SN74ACT240DBR pinout, SN74ACT240DBR application, or SN74ACT240DBR equivalent, key selection considerations include its dual 4-bit independent enable control, high-speed 3-state bus interface capability, rail-to-rail input tolerance, and SSOP-20 package compatibility with dense PCB layouts in network switches and handheld electronics.
Technical Context
The SN74ACT240DBR implements two independent 4-bit inverting buffer sections, each with dedicated output-enable (OE) inputs-1OE controls Y1–Y4 outputs, 2OE controls Y1–Y4 of the second section. Its logic function is strictly inverting: when OE is low, A→Y inversion occurs; when OE is high, all eight outputs enter high-impedance state.
It uses advanced ACT (Advanced CMOS Technology) process, delivering TTL-compatible input thresholds (VIL = 0.8 V, VIH = 2 V), guaranteed VOH ≥3.76 V and VOL ≤0.44 V at 24 mA load, and thermal performance rated at RθJA = 70 °C/W in the DB (SSOP-20) package.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 4.5 V to 5.5 V - Ensures stable operation across standard 5 V supply rails with ±10% tolerance. |
| Max Propagation Delay | 8.5 ns at 5 V - Enables reliable timing in high-speed bus interfaces up to ~100 MHz clock domains. |
| Output Drive | ±24 mA per channel - Sufficient to drive 50 Ω transmission lines or multiple TTL loads without external buffering. |
| Input Voltage Range | 0 V to VCC + 0.5 V - Allows safe interfacing with 5 V logic even when VCC is temporarily absent or ramping. |
| 3-State Enable Logic | Active-low OE (1OE/2OE) - Simplifies bus arbitration and enables clean hot-swap or power sequencing via pull-up to VCC. |
| Operating Temperature | –40 °C to +85 °C - Qualified for commercial and industrial ambient environments without derating. |
| Package | SSOP-20 (DB), 7.2 mm × 7.8 mm body - Surface-mount footprint optimized for automated assembly and board space efficiency. |
Pinout & Package
SN74ACT240DBR is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65 mm lead pitch, 7.2 mm × 7.8 mm body size, and 2.0 mm max height. Pin 1 is located at the top-left corner with index marking; leads are gull-wing shaped for reflow soldering.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1OE | Input | Active-low enable for first 4-bit section (Y1–Y4); tie to VCC via pull-up for power-up high-Z safety. |
| 1A1–1A4 | Inputs | Inverting data inputs for first section; accept TTL/CMOS levels up to 5.5 V regardless of VCC. |
| 2OE | Input | Active-low enable for second 4-bit section (Y1–Y4); independent control enables staggered bus access. |
| 2A1–2A4 | Inputs | Inverting data inputs for second section; electrically isolated from first section except shared VCC/GND. |
| 1Y1–1Y4, 2Y1–2Y4 | Outputs | CMOS push-pull inverted outputs; high-Z when respective OE is high; ±24 mA sink/source capability. |
| VCC (Pin 20) | Power | 5 V supply input; bypass with 0.1 µF ceramic capacitor near pin for noise suppression. |
| GND (Pin 10) | Ground | Signal reference return; must be low-inductance connection to minimize ground bounce during switching. |
Key Features
| Feature | Design Value |
|---|---|
| Inverting 3-state buffer architecture | Dual independent 4-bit sections allow flexible bus partitioning and isolated signal routing in multi-master systems. |
| TTL-compatible inputs with overvoltage tolerance | Accepts 0–5.5 V inputs while powered from 4.5–5.5 V, enabling mixed-voltage system interfacing without level shifters. |
| Balanced CMOS push-pull outputs | Sinks and sources matched current (±24 mA), minimizing skew between rising/falling edges on shared bus lines. |
| Low propagation delay (≤8.5 ns) | Supports setup/hold timing margins in 20+ MHz synchronous buses and reduces cumulative latency in cascaded drivers. |
| High noise immunity | Guaranteed VIH = 2 V / VIL = 0.8 V provides >0.4 V noise margin under worst-case VCC = 4.5 V conditions. |
Applications
| Network Switch Backplane Interface | Smartphone Baseband Bus Isolation |
|---|---|
Use Scenario: Isolating CPU-to-PHY control signals and status lines on multi-layer switch backplanes with shared address/data buses. IC Role / Device Role / Timing Role: Octal inverting buffer providing direction-controlled 3-state isolation between master and slave ASICs during arbitration cycles. Use Value: Prevents bus contention during hot-plug events and ensures deterministic signal integrity with <8.5 ns delay matching across all eight channels. |
Use Scenario: Level-shifting and isolating application processor GPIOs from peripheral modules (camera, sensor hub) in compact smartphone PCBs. IC Role / Device Role / Timing Role: Inverting 3-state driver enabling bidirectional control of shared I²C/SPI auxiliary lines with independent enable per module group. Use Value: Eliminates need for discrete MOSFET switches; 7.2 mm × 7.8 mm SSOP footprint saves >40% board area versus SOIC-20 alternatives. |
| Industrial PLC I/O Expansion Module | Wearable Health Sensor Hub Interface |
Use Scenario: Driving parallel address/data latches and LED indicators in modular programmable logic controller racks with strict EMI limits. IC Role / Device Role / Timing Role: Octal buffer translating microcontroller outputs to robust 24 mA drive for optocoupler inputs and status LEDs. Use Value: Single-chip solution replaces four discrete buffers; ±24 mA drive eliminates external transistor stages and reduces BOM count by 75%. |
Use Scenario: Interfacing ultra-low-power MCU with multiple analog front-end sensors (ECG, SpO₂, accelerometer) requiring isolated digital control paths. IC Role / Device Role / Timing Role: 3-state inverting driver enabling time-multiplexed sensor configuration without cross-talk or leakage current paths. Use Value: Active-low OE allows MCU to place unused sensor channels into high-Z during sleep mode, reducing system standby current by >15 µA per channel. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal 3-state inverting buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74ACT240DWR | SOIC-20 package (12.8 mm × 10.3 mm), RθJA = 101.2 °C/W, same electrical specs and pinout. | Preferred for through-hole prototyping or legacy board designs requiring larger pitch and thermal mass. | Select when manual soldering, higher thermal inertia, or compatibility with existing SOIC footprints is required. |
| SN74ACT240DGSR | VSSOP-20 package (5.1 mm × 4.9 mm), RθJA = 123.5 °C/W, identical logic and AC specs, pin-compatible. | Optimized for ultra-dense wearable and portable designs where board area is constrained below 25 mm². | Choose for space-critical applications; verify thermal management due to higher junction-to-ambient resistance. |
Compared with SN74ACT240DWR and SN74ACT240DGSR, the SN74ACT240DBR offers a middle-ground SSOP footprint (7.2 mm × 7.8 mm) with better thermal performance than VSSOP and 30% smaller area than SOIC-ideal for cost-sensitive industrial boards needing automated assembly and moderate power dissipation.
Availability
SN74ACT240DBR is available at Aetrix Electronics and suitable for network switch backplanes, smartphone baseband subsystems, and industrial PLC I/O modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for SN74ACT240DBR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies with over 90 years of innovation in high-reliability IC design.
The SN74ACT240DBR belongs to TI's legacy ACT logic family, engineered for high-speed, low-noise 3-state bus interfacing in commercial and industrial systems operating at 5 V.
FAQ
What is the logic function of SN74ACT240DBR?
The SN74ACT240DBR implements two independent 4-bit inverting buffer sections. When 1OE or 2OE is low, it passes inverted data from A inputs to Y outputs (e.g., 1A1 → 1Y1). When either OE is high, the corresponding Y outputs enter high-impedance state. This behavior is confirmed in the Function Table (Table 7-1) and logic diagram of the SN74ACT240DBR datasheet.
Does SN74ACT240DBR support 3.3 V logic inputs?
Yes - SN74ACT240DBR inputs are TTL-compatible and accept voltages up to 5.5 V, making them fully compatible with 3.3 V CMOS outputs (which swing 0–3.3 V) when VCC = 5 V. The guaranteed VIH = 2.0 V and VIL = 0.8 V ensure reliable recognition of 3.3 V logic levels without external level shifting.
What is the maximum output current rating per pin for SN74ACT240DBR?
The SN74ACT240DBR is rated for ±24 mA DC output current per Y pin under recommended operating conditions (VCC = 4.5–5.5 V, TA ≤ 85 °C). This value is specified in Section 5.2 (Recommended Operating Conditions) and verified in Electrical Characteristics (Section 5.4) for both IOH and IOL.
Can SN74ACT240DBR be used in automotive applications?
No - SN74ACT240DBR is a catalog-grade device rated for –40 °C to +85 °C operation and is not AEC-Q100 qualified. For automotive use, TI offers the pin-compatible SN74ACT240-Q1, which undergoes extended temperature testing (–40 °C to +125 °C) and failure analysis per automotive reliability standards.
Is SN74ACT240DBR pin-compatible with other packages in the SN74ACT240 family?
Yes - all SN74ACT240 variants (including DB, DGS, DW, NS, PW, RKS, N) share identical pin numbering and signal assignment per Figure 4-1 and Table 4-1. The SN74ACT240DBR pinout matches SN74ACT240DWR and SN74ACT240DGSR exactly, enabling drop-in replacement across SSOP, SOIC, and VSSOP footprints.
SN74ACT240DBR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74ACT
- Package/Case:
- 20-SSOP (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Logic Type:
- Buffer, Inverting
- Number of Elements:
- 2
- Number of Bits per Element:
- 4
- Input Type:
- -
- Output Type:
- 3-State
- Current - Output High, Low:
- 24mA, 24mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SSOP
SN74ACT240DBR FAQ
1.How can I place an order for SN74ACT240DBR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ACT240DBR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for SN74ACT240DBR reliable?
The price and inventory of SN74ACT240DBR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ACT240DBR is usually 5 days.
3.What payment methods are accepted for SN74ACT240DBR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74ACT240DBR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74ACT240DBR?
SN74ACT240DBR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74ACT240DBR order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for SN74ACT240DBR?
For technical support, including SN74ACT240DBR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ACT240DBR requirements.
6.How does Aetrix verify that SN74ACT240DBR is sourced from the original manufacturer or authorized distributors?
All SN74ACT240DBR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SN74ACT240DBR meets industry standards.
7.What is the process for return or replacement of SN74ACT240DBR?
All SN74ACT240DBR units undergo pre-shipment inspection (PSI). If there is an issue with SN74ACT240DBR, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The SN74ACT240DBR part is unused and in its original packaging.
Return procedure for SN74ACT240DBR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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