SN74AC574DWR - Octal D-Type Edge-Triggered F-F, 3-State | TI
N.º da peça: SN74AC574DWR ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $0.92 | $0,92 |
| 10 | $0.83 | $8,30 |
| 100 | $0.71 | $71,00 |
| 500 | $0.62 | $310,00 |
| 1.000 | $0.54 | $540,00 |
SN74AC574DWR Visão geral
What is a D-type edge-triggered flip-flop? A flip-flop is a bistable memory element that captures one bit of data. An edge-triggered D-type flip-flop latches its D input value on the rising edge of the clock and holds that value stable until the next rising edge. When implemented in octal form with shared clock and OE controls, these devices serve as synchronous storage registers commonly used to capture multi-bit parallel data arriving from a bus, sensor array, or processor port. The 3-state output stage allows multiple octal registers to share a common bus without contention, which is why this topology is pervasive in microprocessor and DSP glue logic.
Key features of the SN74AC574 include a typical clock frequency rating that supports high-speed bus interfaces, 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads directly, and inputs that tolerate voltages up to 6 V maximum. These devices are particularly suitable for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers - the canonical applications for an octal registered buffer.
From an architecture standpoint, the SN74AC574 builds on TI's AC advanced CMOS process, which delivers balanced drive strength and lower power dissipation than legacy bipolar or HC families at comparable speeds. Compared with non-edge-triggered latches (such as the '573), edge-triggered '574 removes the critical setup/hold timing pitfalls of transparent latches and is preferred wherever a registered output is needed on a synchronous clock domain.
Typical applications include microprocessor and microcontroller bus expansion (registering address or data lines), memory interface buffering (capturing data into FIFO or RAM arrays), I/O port expansion for industrial controllers, LED drive registers, and parallel ADC/DAC data capture. The wide 2 V to 6 V supply range also makes the part compatible with both 3.3 V and 5 V system rails.
When designing with this device, designers should pay attention to the SOIC-20 land pattern, the required clock pulse width per the datasheet timing table, and the OE timing relative to clock edges to avoid bus contention during asynchronous resets. The 'DW' (SOIC-20) suffix supports standard reflow soldering and reel packaging for high-volume assembly.
This page synthesizes distributor pricing, drop-in pin-compatible alternatives from Texas Instruments and ON Semiconductor, and practical design notes not aggregated in the manufacturer datasheet alone.
Alternativas drop-in para SN74AC574DWR — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
SN74AC574DW
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
SN74AC574N
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
SN74AC574PWR
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
SN74AC574NSR
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MC74AC574DWR2G
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
74ACQ574SCX
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MC74AC574DWG
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
SN74AC574DWR Classificações máximas e características elétricas
| Função | Octal D-Type Edge-Triggered Flip-Flop |
| Number of Elements | 1 |
| Number of Bits per Element | 8 |
| Trigger Type | Positive Edge |
| Tipo de saída | Tri-State (3-State), Non-Inverting |
| Logic Family | AC (Advanced CMOS) |
| Supply Voltage (VCC) | 2 V to 6 V |
| Input Voltage Tolerance | Up to 6 V maximum |
| Temperatura de operação | -40C to +85C |
| Encapsulamento | 20-SOIC (DW), 0.295" / 7.50 mm body width |
| Contagem de pinos | 20 |
| Tipo de montagem | Surface Mount |
| Output Drive | Designed for highly capacitive or low-impedance loads |
| Clock Inputs | 1 (shared, positive-edge triggered) |
| Output Enable (OE) | Yes (active-low, places outputs in high-Z) |
| Status RoHS | Compliant |
Configuração de pinos do SN74AC574DWR
| Pino 1 | OE — Output Enable (active-low). Asserted low enables the 3-state outputs; pulled high, Q outputs are high-impedance. |
| Pino 2 | 1D — Data input for flip-flop 1. |
| Pino 3 | 1Q — 3-state output for flip-flop 1. |
| Pino 4 | 2D — Data input for flip-flop 2. |
| Pino 5 | 2Q — 3-state output for flip-flop 2. |
| Pino 6 | 3D — Data input for flip-flop 3. |
| Pino 7 | 3Q — 3-state output for flip-flop 3. |
| Pino 8 | 4D — Data input for flip-flop 4. |
| Pino 9 | 4Q — 3-state output for flip-flop 4. |
| Pino 10 | GND — Ground reference. |
| Pino 11 | CLK — Clock input, shared positive-edge trigger for all eight flip-flops. |
| Pino 12 | 5D — Data input for flip-flop 5. |
| Pino 13 | 5Q — 3-state output for flip-flop 5. |
| Pino 14 | 6D — Data input for flip-flop 6. |
| Pino 15 | 6Q — 3-state output for flip-flop 6. |
| Pino 16 | 7D — Data input for flip-flop 7. |
| Pino 17 | 7Q — 3-state output for flip-flop 7. |
| Pino 18 | 8D — Data input for flip-flop 8. |
| Pino 19 | 8Q — 3-state output for flip-flop 8. |
| Pino 20 | VCC — Supply voltage, 2 V to 6 V. |
Aplicações típicas
SN74AC574DWR é adequado para 7 aplicaçãos: Microprocessor Bus Register, Output Port Expander, LED Display Driver Register, Data Capture for Parallel ADC/DAC, Buffer Register / Memory Interface, Bidirectional Bus Buffer (with 245), Power-Sequencing Control Register.
Microprocessor Bus Register
The SN74AC574DWR's eight edge-triggered D-type flip-flops share one positive-edge clock, making it a natural fit as a synchronous register on an 8-bit or 16-bit demultiplexed address/data bus. Its 2V-6V VCC tolerance handles both 3.3V and 5V MCUs cleanly, while the 3-state outputs let multiple registered peripherals share a common bus without contention. Versus slower HC-family latches, AC logic preserves tight setup/hold margins for high-speed CPUs.
Recomendado
Output Port Expander
The SN74AC574DWR captures one byte from a low-pin-count microcontroller and holds it on eight parallel output pins, freeing the MCU from repetitive bit-banging. With AC-logic drive strength, the registered outputs swing rail-to-rail and can sink/source directly into relay coils, LEDs, or optocoupler arrays without external buffers. The shared OE pin enables rapid multiplexing between multiple 574s for 16/24/32-bit output expansion on the same bus.
Recomendado
LED Display Driver Register
Each SN74AC574DWR can store one row or column of an LED matrix display, allowing the host controller to shift data once and let the 574 hold steady-state current on the LEDs between refreshes. The AC family's fast edge rates minimize transition glitches in multiplexed 7-segment or dot-matrix displays, while the 3-state outputs ease cascading of multiple 574s for large-digit panels. The wide operating temperature range accommodates both indoor and outdoor signage.
Recomendado
Data Capture for Parallel ADC/DAC
The SN74AC574DWR captures output bytes from a parallel ADC or feeds input bytes to a parallel DAC, providing a one-clock-cycle pipeline stage that decouples conversion latency from downstream processing. Its edge-triggered behavior eliminates the transparency window of latches, eliminating race conditions in synchronous DSP pipelines. The 3-state outputs allow the same data lines to be shared with memory-mapped peripherals during read-back.
Recomendado
Buffer Register / Memory Interface
The SN74AC574DWR functions as a 1-byte holding register between high-speed processors and slower memory devices, easing timing closure on address or data paths with significant propagation delay. Used in pairs around a bus, two 574s create a registered memory interface that absorbs timing skew and relaxes downstream timing budgets. AC-logic drive strength cleanly drives SRAM/EEPROM control inputs without external buffers in many designs.
Recomendado
Bidirectional Bus Buffer (with 245)
Combined with an SN74AC245 bus transceiver, the SN74AC574DWR forms a register-and-isolate stage that supports hot-swap or level shifting between two bus domains. The 3-state outputs of the 574 isolate cleanly when bus direction is reversed, while the 245 controls direction during write/read transitions. AC logic family compatibility eliminates speed mismatch between the two devices in the same timing chain.
Recomendado
Power-Sequencing Control Register
The SN74AC574DWR's 3-state outputs and rail-to-rail AC-family drive make it suitable for sequencing eight power-rail enable lines in a controlled power-up/power-down order. A microcontroller loads the desired enable pattern once, and the 574 holds that pattern stable across all rail transitions. The shared OE pin lets the host instantly tri-state the enable lines for emergency shutdown.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para SN74AC574DWR — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | SN74AC574DW | SN74AC574N | SN74AC574PWR | MC74AC574DWR2G | MC74AC574DWG |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | onsemi | onsemi |
| Package | SOIC-20 (DW) | SOIC-20 (DW) - same | PDIP-20 (N) - same | TSSOP-20 (PW) - same | SOIC-20 (DW) - same | SOIC-20 (DW) - same |
| Logic Family | AC (Advanced CMOS) | AC | AC | AC | AC (equivalent AC family) | AC (equivalent AC family) |
| Supply Voltage (VCC) | 2 V to 6 V | 2 V to 6 V | 2 V to 6 V | 2 V to 6 V | 2 V to 6 V | 2 V to 6 V |
| Function | Octal D-type edge-triggered F-F | Octal D-type edge-triggered F-F | Octal D-type edge-triggered F-F | Octal D-type edge-triggered F-F | Octal D-type edge-triggered F-F | Octal D-type edge-triggered F-F |
| Output Type | Tri-State (Non-Inverting) | Tri-State (Non-Inverting) | Tri-State (Non-Inverting) | Tri-State (Non-Inverting) | Tri-State (Non-Inverting) | Tri-State (Non-Inverting) |
| Trigger Type | Positive Edge | Positive Edge | Positive Edge | Positive Edge | Positive Edge | Positive Edge |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| RoHS / Lead-Free | Compliant | Compliant | Compliant | Compliant | Compliant | Compliant |
Principais diferenciais
- Same-author SOIC-20 alternative with full sourcing resilience (vs MC74AC574DWR2G)
- Same pinout across multiple package options (vs SN74AC574N (PDIP-20))
- Tri-state outputs drive capacitive loads directly (vs MC74AC574DWG)
Notas de projeto
Estimated: For SOIC-20 (DW) layout, allocate a 1.27 mm pin pitch land pattern with a thermal pad footprint recommendation. Place a 100 nF decoupling capacitor within 3 mm of the VCC pin (20) and a 100 nF bulk capacitor at the board's VCC entry point. Keep clock trace short and routed over a continuous ground plane to minimize skew across the 8-bit register.
The SN74AC574DWR's AC family has fast edge rates (~3 ns typical) capable of driving highly capacitive bus loads, but long PCB traces or unterminated buses can cause reflections. Estimated: if bus length exceeds approximately 50 mm, add a series damping resistor near each output. Always hold OE high during clock transitions if the bus is being shared with another driver to prevent bus contention.
Do not leave the OE pin floating; unused OE must be tied low (to enable outputs) through a 10 kohm resistor to GND if not actively driven. Floating D inputs on unconnected flip-flops can float into the linear region and increase supply current. Always satisfy the datasheet-specified setup time (tsu) and hold time (th) around the rising clock edge to avoid metastability in synchronous designs.
Informações de conformidade
RoHS and lead-free per TI product page. AEC-Q100 not qualified; for automotive applications, look for SN74AC574-Q1 derivatives. Halogen-free status [DATA_NEEDED]. REACH compliance per TI material declarations.
