SN74LVC240A - Octal Inverting Buffer 3-State LVC | TI
N.º da peça: SN74LVC240A ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $0.55 | $0,55 |
| 10 | $0.48 | $4,80 |
| 100 | $0.35 | $35,00 |
| 500 | $0.28 | $140,00 |
| 1.000 | $0.22 | $220,00 |
SN74LVC240A Visão geral
An octal buffer/line driver is a digital logic IC in the 74xx logic family that provides signal buffering, inversion, and bus isolation. Within the logic-IC hierarchy, the SN74LVC240A belongs to the Low-Voltage CMOS (LVC) technology family, a subfamily of 74-series logic. Its 3-state outputs allow multiple devices to share a common bus without contention, a fundamental requirement in bus-oriented digital systems such as memory subsystems and backplanes.
Key features include 5.5-V tolerant inputs enabling mixed-mode signal operation on all ports (5-V input/output voltage support), a typical propagation delay (tpd) of 3.3 ns at VCC = 3.3 V, and low typical VOLP (output ground bounce) and VOHV (output VOH undershoot) figures for superior signal integrity. According to the TI datasheet (SCAS293), the device can drive a load with total capacitance less than or equal to 50 pF while still meeting all datasheet specifications.
The device is built on advanced CMOS technology, combining low static power consumption with high noise immunity and strong output drive. The dual-bank structure with separate active-low output-enable (OE) inputs supports half-duplex transceiver topologies and word-wide bus gating. When OE is low, data passes from the A inputs to the inverted Y outputs; when OE is high, outputs enter the high-impedance state.
Typical applications include 3-state memory address and clock driving, 3.3-V to 5-V mixed-voltage bus interfacing, industrial control I/O buffering, and telecom line-card logic. Packages include SOIC-20 (DW), TSSOP-20 (PW), and SSOP-20 (DB).
Design tip: keep total capacitive load at or below 50 pF for guaranteed timing, add 0.1 uF decoupling per supply pin, and tie unused inputs to VCC or GND to prevent floating-node oscillation.
Alternativas drop-in para SN74LVC240A — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Variantes desta série
Modelos da mesma série compatíveis como drop-in com SN74LVC240A (mesmo formato e footprint) — diferindo em Output Type.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
SN74LV240A
✓ Em estoque
$0.19 / unidade
Ver ficha técnica →SN74LVC240A-Q1
📋 Alternativa de referência (fora do catálogo)
SN74AHCT240A
📋 Alternativa de referência (fora do catálogo)
74LVC240APW
📋 Alternativa de referência (fora do catálogo)
74LVC240AMTC
📋 Alternativa de referência (fora do catálogo)
74LVC240APW-13
📋 Alternativa de referência (fora do catálogo)
SN74LVC240A Classificações máximas e características elétricas
| Função | Octal inverting buffer/driver with 3-state outputs |
| Supply Voltage Range | 1.65 V to 3.6 V |
| Nominal Operating Voltage | 3.3 V |
| Input Tolerance | 5.5 V regardless of VCC |
| Canais | 8 (two 4-bit banks with separate OE) |
| Tipo de saída | 3-state, inverting |
| Propagation Delay (tpd) | 3.3 ns typ at VCC = 3.3 V |
| Max Capacitive Load | 50 pF (for guaranteed datasheet specs) |
| Packages | SOIC-20 (DW), TSSOP-20 (PW), SSOP-20 (DB) |
| Tipo de montagem | Surface Mount |
| Logic Family | LVC (Low-Voltage CMOS) |
| Output Enable | Active-low OE per 4-bit bank |
| Status RoHS | Compliant |
Configuração de pinos do SN74LVC240A
| Pino 1 | 1OE — Output enable, bank 1 (active low) |
| Pino 2 | 1A1 — Bank 1 input 1 |
| Pino 3 | 2Y4 — Bank 2 output 4 (inverted, 3-state) |
| Pino 4 | 2A4 — Bank 2 input 4 |
| Pino 5 | 2Y3 — Bank 2 output 3 (inverted, 3-state) |
| Pino 6 | 2A3 — Bank 2 input 3 |
| Pino 7 | 2Y2 — Bank 2 output 2 (inverted, 3-state) |
| Pino 8 | 2A2 — Bank 2 input 2 |
| Pino 9 | 2Y1 — Bank 2 output 1 (inverted, 3-state) |
| Pino 10 | GND — Ground |
| Pino 11 | 2A1 — Bank 2 input 1 |
| Pino 12 | 1Y1 — Bank 1 output 1 (inverted, 3-state) |
| Pino 13 | 1A2 — Bank 1 input 2 |
| Pino 14 | 1Y2 — Bank 1 output 2 (inverted, 3-state) |
| Pino 15 | 1A3 — Bank 1 input 3 |
| Pino 16 | 1Y3 — Bank 1 output 3 (inverted, 3-state) |
| Pino 17 | 1A4 — Bank 1 input 4 |
| Pino 18 | 1Y4 — Bank 1 output 4 (inverted, 3-state) |
| Pino 19 | 2OE — Output enable, bank 2 (active low) |
| Pino 20 | VCC — Power supply, 1.65 V to 3.6 V |
Aplicações típicas
SN74LVC240A é adequado para 6 aplicaçãos: Memory Address and Clock Driving, 3.3V to 5V Mixed-Voltage Bus Interfacing, Industrial Control I/O Buffering, Bus-Oriented Receivers and Transmitters, Telecom Line-Card Logic, Microcontroller Peripherals and GPIO Expansion.
Memory Address and Clock Driving
The SN74LVC240A is purpose-built per the TI datasheet (SCAS293) to improve the performance and density of 3-state memory address drivers and clock drivers. Its 3.3-ns typical propagation delay and 50-pF guaranteed capacitive drive keep address and clock edges sharp across DRAM/SRAM buses, while 3-state outputs let the processor, DMA, and test logic share address lines without contention. Two independently enabled 4-bit banks allow half-bus gating during refresh or boot modes. Place parts close to the memory connector and keep stubs under the 50-pF load budget for guaranteed timing.
Recomendado
3.3V to 5V Mixed-Voltage Bus Interfacing
Thanks to 5.5-V tolerant inputs independent of VCC, the SN74LVC240A accepts legacy 5-V logic signals while running from a 3.3-V rail, per TI datasheet SCAS293. This supports mixed-mode signal operation on all ports - a 3.3-V-powered board can directly receive 5-V microcontroller or backplane outputs without clamp diodes or series protection. Outputs swing to 3.3 V, so use it on paths where the receiving 5-V device recognizes 3.3-V levels (true for most TTL-threshold inputs). This eliminates level-shifting ICs on receive-only paths, saving BOM cost and board area.
Recomendado
Industrial Control I/O Buffering
In PLC I/O racks and industrial control boards, the SN74LVC240A buffers sensor and actuator logic signals with strong CMOS drive and high noise immunity across a 1.65-V to 3.6-V supply. The dual-bank, independently enabled 3-state structure isolates I/O groups during configuration or fault conditions, and the low VOLP ground-bounce specification keeps switching transients off shared ground planes in electrically noisy factory environments. Its wide -40C-to-125C-grade availability and low per-channel cost (about $0.03/channel at volume) make it economical for high channel-count buffering.
Recomendado
Bus-Oriented Receivers and Transmitters
The SN74LVC240A fits backplane and board-level bus transceiver architectures where the TI datasheet (SCAS293) explicitly targets bus-oriented receivers and transmitters. 3-state outputs allow multiple line cards or peripherals to drive a shared data bus under OE control, and the inverting function pairs with non-inverting buffers (such as the LVC244) to build latch-through or XOR-parity bus topologies. Low typical VOHV output undershoot protects neighboring receiver inputs during simultaneous switching, supporting reliable multi-drop communication at 3.3-V logic speeds.
Recomendado
Telecom Line-Card Logic
Telecom line cards use the SN74LVC240A for address decoding buffers, clock distribution to SLIC/SLAC devices, and 3-state isolation of shared control buses during hot-swap or maintenance windows. The 5.5-V tolerant inputs accept legacy 5-V control signals common in carrier equipment, while the device runs on the modern 3.3-V card rail. Its low static CMOS power consumption reduces per-card dissipation across high-density shelves, and SOIC-20/TSSOP-20 packages suit both wave-soldered and reflow line-card assembly processes used in telecom manufacturing.
Recomendado
Microcontroller Peripherals and GPIO Expansion
Around MCUs such as the MSP430 and TMS320 families, the SN74LVC240A expands buffered GPIO, drives LED/status arrays through current-limiting resistors, and isolates shared peripheral buses (memory-mapped displays, FPGAs, external SRAM) during reset. The separate 1OE/2OE enables let firmware gate I/O banks independently, and 3-state outputs prevent bus fight between the MCU and FPGA during configuration. Its 3.3-ns delay adds negligible timing overhead to MCU bus cycles, and the 5-V tolerant inputs safely interface 5-V legacy modules.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para SN74LVC240A — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | SN74LV240A | SN74LVC240A-Q1 | 74LVC240APW | SN74AHCT240A |
|---|---|---|---|---|---|
| Package | TSSOP-20 (PW) | TSSOP-20 (PW) - same | TSSOP-20 (PW) - same | TSSOP-20 (PW) - same | TSSOP-20 (PW) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Nexperia | Texas Instruments |
| 5.5V-Tolerant Inputs | Yes | No | Yes | Yes | N/A (5V supply) |
| Function | Inverting, 3-state, dual 4-bit banks | Inverting, 3-state - same | Inverting, 3-state - same | Inverting, 3-state - same | Inverting, 3-state - same |
| Automotive Grade | No | No | Yes (AEC-Q100) | No | No |
| Best For | Mixed 3.3V/5V bus interfacing | Cost-driven 3.3V buffering | Automotive designs | Second-source supply | 5V CMOS logic domains |
Principais diferenciais
- 5.5-V tolerant inputs on a 3.3-V rail (vs SN74LV240A)
- Automotive qualification available (vs SN74LVC240A-Q1)
- Wide low-voltage supply range (vs SN74AHCT240A)
Notas de projeto
Per TI datasheet SCAS293, the SN74LVC240A guarantees all specifications only when total capacitive load is at or below 50 pF. In high-speed bus designs, budget trace capacitance (roughly 1-2 pF per cm of PCB trace) plus receiver input capacitance against this 50-pF limit. For heavier loads, series-terminate (22-33 ohm) to control edge rate and reflections, or split the bus across more drivers.
Place a 0.1 uF ceramic decoupling capacitor within 2-3 mm of each VCC pin, with one bulk 4.7-10 uF capacitor per group of octal buffers. Simultaneous switching of eight outputs can induce ground bounce; the datasheet's low typical VOLP specification is achieved only with a solid, low-inductance ground return - use vias directly to the ground plane at pin 10.
Tie unused inputs to VCC or GND - never leave them floating, as floating CMOS inputs can oscillate and increase static current. Remember the outputs are inverting: a LOW input produces a HIGH output. OE pins are active-low, so pull OE high (or use a pullup) during power-up if bus contention must be avoided until firmware takes control.
Informações de conformidade
Standard TI catalog logic device, RoHS compliant; confirm exact suffix (-NOPB) material declarations on TI product page. AEC-Q100 version available as SN74LVC240A-Q1.
