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Texas Instruments SN74AC574DBR
- Part No.:
- SN74AC574DBR
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 20-SSOP (0.209", 5.30mm Width)
- Datasheet:
-
SN74AC574DBR.pdf
- Description:
- IC FF D-TYPE SNGL 8BIT 20SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,231
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Product details
Overview
SN74AC574DBR from Texas Instruments is an octal D-type edge-triggered flip-flop with 3-state outputs, designed for bus interface and data latching in digital systems. It operates from 2V to 6V VCC, delivers 8.5ns max propagation delay at 5V, and supports rising-edge clock triggering with independent output-enable control. It is used in I/O port expansion, bidirectional bus driving, and buffer register applications.
For engineers reviewing the SN74AC574DBR datasheet, SN74AC574DBR pinout, SN74AC574DBR application, or SN74AC574DBR equivalent, key selection criteria include its 20-pin SSOP package, 3-state output drive capability, 5V/3.3V compatibility, and timing margins for synchronous bus interfacing in industrial and embedded controllers.
Technical Context
This device implements eight independent D-type flip-flops sharing a common clock (CLK) input and a single active-low output-enable (OE) signal. Each flip-flop captures the logic state of its D input on the rising edge of CLK and holds it until the next clock transition.
The 3-state outputs allow direct connection to shared data buses without external pull-ups or isolation logic; OE controls all eight outputs simultaneously, placing them in high-impedance when asserted low, while internal latch operation remains unaffected.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2V to 6V - supports mixed-voltage system interfacing (e.g., 3.3V logic driving 5V bus) |
| Max tpd | 8.5ns at 5V - enables reliable operation up to 85MHz clock frequency in synchronous designs |
| Output Drive | ±24mA at 5V - sufficient to drive standard TTL loads and moderate-capacitance buses directly |
| Input Voltage Tolerance | Up to 6V regardless of VCC - allows safe interfacing with higher-voltage signals without level shifters |
| Setup/Hold Times | tsu = 2ns, th = 1.5ns at 5V - tight timing windows require clean clock edges and controlled trace routing |
| Power Dissipation | Cpd = 40pF - enables accurate dynamic power estimation in high-speed switching applications |
Pinout & Package
SN74AC574DBR is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65mm lead pitch, 7.2mm × 7.8mm body-plus-lead footprint, and 2mm max height. The package is RoHS-compliant, moisture-sensitive Level-1, and optimized for surface-mount assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (OE) | Active-low output enable | Asserting low disables all Q outputs into high-impedance; does not affect internal latch state |
| 2–9 (D1–D8) | Data inputs | Asynchronous inputs sampled only on rising CLK edge; must be stable during setup/hold window |
| 10 (GND) | Ground reference | Primary return path for all I/O and supply currents; requires low-inductance PCB connection |
| 11 (CLK) | Clock input | Rising-edge triggered; internal Schmitt trigger not present - requires monotonic, fast-rising edge (≤8 ns/V) |
| 12–19 (Q8–Q1) | 3-state outputs | Order reversed (Q8 first) to match physical pin layout; each reflects corresponding D input after CLK↑ |
| 20 (VCC) | Positive supply | Must be bypassed locally with 0.1µF ceramic capacitor; supports 2V–6V operation |
Key Features
| Feature | Design Value |
|---|---|
| Wide VCC range (2V–6V) | Enables interoperability across 3.3V and 5V domains without level translation circuitry |
| 3-state outputs with common OE | Allows time-multiplexed bus sharing among multiple devices using a single enable control line |
| 8.5ns max tpd at 5V | Supports high-speed data capture in microcontroller peripheral interfaces and FPGA glue logic |
| Input tolerance to 6V | Permits direct connection to legacy 5V buses or open-drain pull-up networks without clamping diodes |
| High noise immunity | Guaranteed 0.9V/2.1V input thresholds at 3V VCC provide >1.2V noise margin under worst-case conditions |
Applications
| Industrial PLC I/O Expansion | Microcontroller Parallel Interface Buffer |
|---|---|
Use Scenario: Adding 8-bit parallel input/output capability to a programmable logic controller mainboard via backplane bus. IC Role / Device Role / Timing Role: Latches incoming sensor data on rising CLK edge and presents it to the CPU bus via 3-state outputs enabled by address decoder. Use Value: Eliminates need for discrete buffers or bus transceivers; reduces BOM count and PCB area while maintaining timing integrity at 20MHz bus rates. | Use Scenario: Interfacing an 8-bit microcontroller with external memory-mapped peripherals requiring synchronized data capture. IC Role / Device Role / Timing Role: Captures parallel status signals from sensors or switches and holds them stable for CPU read access during variable instruction cycles. Use Value: Provides deterministic setup/hold timing (2ns/1.5ns) compatible with 8051- and ARM Cortex-M-based controllers running at ≤25MHz. |
| Legacy Bus Transceiver Replacement | Digital Test Equipment Data Capture |
Use Scenario: Replacing obsolete 74LS244/245 transceivers in aging instrumentation chassis with modern low-power, high-speed equivalents. IC Role / Device Role / Timing Role: Bidirectional bus driver where OE controls direction and CLK synchronizes data flow between two asynchronous subsystems. Use Value: Reduces power consumption by >80% versus LS-TTL while improving noise margin and eliminating external pull-ups required by open-collector alternatives. | Use Scenario: Capturing parallel digital waveform samples from a 100MHz logic analyzer front-end before serial transmission to host PC. IC Role / Device Role / Timing Role: Edge-triggered latch capturing 8-bit nibbles on each clock cycle; outputs driven onto local FIFO bus under OE control. Use Value: Enables precise timestamp alignment of captured data with system clock due to guaranteed 8.5ns propagation delay and minimal skew across all 8 channels. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal D-type latch applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LVC574APWR | Lower VCC range (1.65V–3.6V); 3.3V-only operation; 6.7ns tpd; higher drive (±24mA) | Optimized for modern low-voltage systems; not suitable for 5V bus interfacing | Select when operating exclusively at 3.3V and requiring lower power or tighter timing margins |
| 74ACT574SC | Same 4.5V–5.5V VCC range; 10ns tpd; TTL-compatible inputs; no 3.3V support | Designed for legacy 5V-only systems; lacks 3.3V compatibility and wide-supply flexibility | Select for drop-in replacement in existing 5V designs where AC-family timing and drive are required |
Compared with SN74AC574DBR, SN74LVC574APWR offers better performance at 3.3V but sacrifices 5V interoperability, while 74ACT574SC maintains strict 5V compatibility at the cost of wider supply range and higher static current - making SN74AC574DBR the optimal choice for mixed-voltage or voltage-flexible designs.
Availability
SN74AC574DBR is available at Aetrix Electronics and suitable for industrial automation, test equipment, and embedded controller applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.
Supply support for SN74AC574DBR 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 delivering analog and embedded processing solutions, with over 90 years of innovation in logic, power management, and signal chain technologies.
The SN74AC574DBR belongs to TI's AC-series advanced CMOS logic family, engineered for high-speed, low-power, and wide-supply-voltage operation in industrial and communications infrastructure applications.
FAQ
What is the maximum clock frequency supported by SN74AC574DBR at 5V?
At VCC = 5V ± 0.5V and TA = 25°C, SN74AC574DBR supports a maximum clock frequency of 85MHz. This value is derived from timing requirements including minimum pulse width (5ns), setup time (2ns), and hold time (1.5ns), ensuring reliable edge-triggered operation in synchronous bus environments.
Does SN74AC574DBR require external pull-up resistors on its outputs?
No, SN74AC574DBR does not require external pull-up resistors on its outputs. Its 3-state outputs actively drive high or low when enabled, and enter high-impedance when OE is high. Pull-ups are unnecessary unless interfacing with open-drain systems - a configuration not supported by SN74AC574DBR's push-pull output architecture.
Can SN74AC574DBR operate reliably at 3.3V VCC?
Yes, SN74AC574DBR operates reliably at 3.3V VCC. Its recommended operating range is 2V to 6V, and electrical characteristics are fully specified at 3.3V ± 0.3V, including 55MHz max clock frequency, 13.5ns max tPLH, and guaranteed input thresholds (VIH = 2.1V, VIL = 0.9V).
What is the thermal resistance (RθJA) of the SN74AC574DBR package?
The SN74AC574DBR in its DB (SSOP-20) package has a junction-to-ambient thermal resistance (RθJA) of 70°C/W, measured under standard JEDEC JESD51-2 conditions. This value assumes a 1-inch² copper pad with 2oz copper and no internal planes; actual board-level performance may vary based on layout and airflow.
Is SN74AC574DBR pin-compatible with other members of the '574 family?
SN74AC574DBR shares identical pinout and function with SN74AC574 variants in DW (SOIC), PW (TSSOP), and N (PDIP) packages. However, it is not pin-compatible with non-AC series devices such as SN74LS574 or SN74HC574 due to differences in output structure, timing, and supply voltage ranges - always verify package drawing DB0020A for SN74AC574DBR.
SN74AC574DBR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74AC
- Package/Case:
- 20-SSOP (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Standard
- Type:
- D-Type
- Output Type:
- Tri-State, Non-Inverted
- Number of Elements:
- 1
- Number of Bits per Element:
- 8
- Clock Frequency:
- 153 MHz
- Max Propagation Delay @ V, Max CL:
- 9.5ns @ 5V, 50pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 24mA, 24mA
- Voltage - Supply:
- 2V ~ 6V
- Current - Quiescent (Iq):
- 4 µA
- Input Capacitance:
- 4.5 pF
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SSOP
SN74AC574DBR FAQ
1.How can I place an order for SN74AC574DBR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74AC574DBR 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 SN74AC574DBR reliable?
The price and inventory of SN74AC574DBR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74AC574DBR is usually 5 days.
3.What payment methods are accepted for SN74AC574DBR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74AC574DBR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74AC574DBR?
SN74AC574DBR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74AC574DBR 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 SN74AC574DBR?
For technical support, including SN74AC574DBR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74AC574DBR requirements.
6.How does Aetrix verify that SN74AC574DBR is sourced from the original manufacturer or authorized distributors?
All SN74AC574DBR 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 SN74AC574DBR meets industry standards.
7.What is the process for return or replacement of SN74AC574DBR?
All SN74AC574DBR units undergo pre-shipment inspection (PSI). If there is an issue with SN74AC574DBR, 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 SN74AC574DBR part is unused and in its original packaging.
Return procedure for SN74AC574DBR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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