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Texas Instruments SN74HCT574DBRE4
- Part No.:
- SN74HCT574DBRE4
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 20-SSOP (0.209", 5.30mm Width)
- Datasheet:
-
SN74HCT574DBRE4.pdf
- Description:
- IC FF D-TYPE SNGL 8BIT 20SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,205
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Product details
Overview
SN74HCT574DBRE4 from Texas Instruments is an octal edge-triggered D-type flip-flop with 3-state noninverting outputs, designed for bus interface and data latching in 5V digital systems. It operates from 4.5V to 5.5V, delivers ±6mA output drive, features 22ns typical propagation delay (tpd), and draws ≤80μA quiescent current - enabling direct TTL-load driving in I/O port and register applications.
For engineers reviewing the SN74HCT574DBRE4 datasheet, SN74HCT574DBRE4 pinout, SN74HCT574DBRE4 application, or SN74HCT574DBRE4 equivalent, key selection criteria include its 20-pin SSOP package, dual independent 3-state enable control (1OE/2OE), positive-edge clock triggering, bus-structured pinout, and compatibility with LSTTL loads without external pull-ups.
Technical Context
This device implements eight independent D-type flip-flops, each capturing input data on the low-to-high transition of CLK. Its dual output-enable inputs (1OE and 2OE) independently control two groups of four outputs, allowing segmented bus access and reducing contention during multi-device sharing.
The 3-state outputs exhibit high-current drive (±6mA at 5V) and low leakage (≤0.5μA IOZ), while input thresholds are TTL-compatible (VIH = 2V min, VIL = 0.8V max). Timing is characterized at CL = 50 pF and CL = 150 pF, with tpd ranging from 25ns to 66ns depending on VCC and load.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5V–5.5V - ensures interoperability with standard 5V TTL and CMOS logic rails. |
| Propagation Delay (tpd) | 25ns (5.5V, CL=50pF) - supports up to 27MHz clock operation in high-speed bus buffering. |
| Output Drive | ±6mA at 5V - directly drives 15 LSTTL loads without external buffers or pull-ups. |
| Quiescent Current (ICC) | ≤80μA - enables low-power operation in battery-backed or standby-aware register designs. |
| Input Compatibility | TTL-voltage compatible (VIH ≥ 2V, VIL ≤ 0.8V) - interfaces seamlessly with legacy 74LS and microcontroller GPIOs. |
| 3-State Leakage (IOZ) | ≤0.5μA - minimizes bus leakage and crosstalk when outputs are disabled. |
| Setup/Hold Time | tsu = 17ns, th = 5ns (5.5V) - defines minimum data stability window before and after CLK edge for reliable capture. |
Pinout & Package
SN74HCT574DBRE4 is packaged in a 20-pin SSOP (DB) with 0.65mm lead pitch, body size 7.2mm × 5.3mm, and 1.2mm max height. The package supports surface-mount assembly with exposed thermal pad (non-electrical) and is RoHS-compliant with NIPDAU lead finish and MSL Level-1 rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1OE | Input | Active-low enable for outputs Y1–Y4; controls first quad group independently. |
| 1A1–1A4 | Input | Data inputs for first four flip-flops (D1–D4). |
| 2Y1–2Y4 | Output | 3-state noninverting outputs for second quad group (Q5–Q8). |
| 2OE | Input | Active-low enable for outputs Y1–Y4; controls second quad group independently. |
| 2A1–2A4 | Input | Data inputs for second four flip-flops (D5–D8). |
| 1Y1–1Y4 | Output | 3-state noninverting outputs for first quad group (Q1–Q4). |
| GND | Power | Ground reference for all logic and output stages. |
| VCC | Power | Positive supply rail (4.5V–5.5V); decoupling required per TI recommendation (0.1μF ceramic). |
| CLK | Input | Common clock input; triggers all eight flip-flops on rising edge. |
Key Features
| Feature | Design Value |
|---|---|
| Bus-structured pinout | Minimizes PCB trace length and crosstalk between data inputs and corresponding outputs (e.g., 1A1 adjacent to 1Y1). |
| Dual independent 3-state enables | Allows interleaved or segmented bus access - e.g., Q1–Q4 active while Q5–Q8 tri-stated - supporting partial-word transfers. |
| High-current 3-state outputs | ±6mA drive capability eliminates need for external bus drivers in most 5V system interconnects. |
| TTL-compatible inputs | Accepts standard 74LS logic levels without level-shifting, simplifying integration with legacy controllers and peripherals. |
| Low power consumption | 80μA max ICC enables use in power-sensitive register files and I/O expanders without thermal derating. |
Applications
| Industrial PLC I/O Expansion | Microcontroller Parallel Port Buffering |
|---|---|
Use Scenario: Expanding GPIO count of an ARM Cortex-M4 MCU to drive 16-bit parallel LCD interface and discrete LED indicators. IC Role / Device Role / Timing Role: Acts as bidirectional data latch and bus driver; CLK synchronized to MCU write strobe, OE controlled by address decoder. Use Value: Enables single-cycle parallel writes without software bit-banging; 3-state isolation prevents bus contention during read-modify-write sequences. |
Use Scenario: Isolating and latching sensor data from 8-bit ADC before transfer to an 8051-based data logger. IC Role / Device Role / Timing Role: Serves as input register; CLK triggered by ADC EOC signal, outputs held stable during MCU polling cycle. Use Value: Eliminates sampling uncertainty caused by asynchronous ADC-to-MCU handshaking; ±6mA drive ensures clean signal integrity over 10cm PCB traces. |
| Legacy Bus Interface Adapter | Test Equipment Digital Pattern Generator |
Use Scenario: Bridging ISA bus data lines to modern FPGA-based controller in retro-computing restoration project. IC Role / Device Role / Timing Role: Functions as bidirectional bus transceiver; 1OE/2OE mapped to ISA IOR/IOW signals, CLK tied to ISA BCLK. Use Value: Provides level- and timing-compliant interface without custom logic; TTL-compatible inputs accept ISA's 2.4V VIH threshold directly. |
Use Scenario: Generating synchronized 8-bit stimulus waveforms for IC functional testing using pattern generator firmware. IC Role / Device Role / Timing Role: Used as output register; CLK driven by programmable timer, OE controlled by test sequence state machine. Use Value: Guarantees glitch-free waveform edges via edge-triggered capture; 22ns tpd allows >20MHz pattern update rates under 50pF load. |
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 |
|---|---|---|---|
| SN74HCT374DBR | Identical pinout and function but with single shared OE (vs. dual OE in SN74HCT574DBRE4); same 20-pin SSOP package. | Lacks independent control of output groups - unsuitable for segmented bus arbitration or partial-word transfers. | Select when simplified enable logic suffices and cost reduction is prioritized over bus segmentation flexibility. |
| 74ACT574MTCX | Higher speed (tpd = 9ns typ), wider VCC range (4.5V–5.5V), but higher ICC (40mA max) and no dual OE; TSSOP-20 package. | Not drop-in due to different timing margins and power delivery requirements; requires layout review for noise and decoupling. | Choose for high-throughput applications where sub-10ns latency outweighs power and control granularity trade-offs. |
Compared with SN74HCT374DBR and 74ACT574MTCX, SN74HCT574DBRE4 uniquely balances low power, dual-group 3-state control, and proven 5V bus compatibility - making it optimal for industrial I/O expansion and mixed-signal interface designs requiring deterministic enable sequencing.
Availability
SN74HCT574DBRE4 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, microcontroller parallel port buffering, and legacy bus interface adapter applications requiring stable component supply across extended product lifecycles.
Supply support for SN74HCT574DBRE4 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 logic solutions, with decades of heritage in industry-standard logic families.
SN74HCT574DBRE4 belongs to the 74HCT high-speed CMOS logic series, engineered for 5V TTL-compatible operation in industrial control, instrumentation, and computing infrastructure where reliability and interoperability are critical.
FAQ
What is the maximum clock frequency supported by SN74HCT574DBRE4?
SN74HCT574DBRE4 supports up to 27MHz maximum clock frequency at VCC = 5.5V and CL = 50pF, as specified in the switching characteristics table. At 4.5V and CL = 50pF, fmax drops to 24MHz. These values assume proper PCB layout, decoupling (0.1μF ceramic capacitor near VCC), and termination to minimize ringing and ensure setup/hold compliance. SN74HCT574DBRE4 does not guarantee operation beyond these limits under recommended conditions.
Does SN74HCT574DBRE4 support independent control of its two output groups?
Yes, SN74HCT574DBRE4 provides two independent 3-state enable inputs: 1OE controls outputs Y1–Y4 (Q1–Q4), and 2OE controls outputs Y1–Y4 (Q5–Q8). This allows segmented bus access - for example, holding Q1–Q4 active while tri-stating Q5–Q8 during partial-word transfers. Both enables are active-low and do not affect internal flip-flop operation or data retention.
Can SN74HCT574DBRE4 drive standard LSTTL loads directly?
Yes, SN74HCT574DBRE4 is explicitly rated to drive up to 15 LSTTL loads directly, thanks to its ±6mA output drive capability at 5V. This eliminates the need for external buffer ICs in most 5V system interconnects. The device's TTL-compatible input thresholds (VIH ≥ 2V, VIL ≤ 0.8V) further ensure seamless interfacing with legacy LSTTL sources without level translation.
What is the recommended decoupling for SN74HCT574DBRE4?
Texas Instruments recommends a 0.1μF ceramic capacitor placed as close as possible to the VCC pin of SN74HCT574DBRE4 to suppress high-frequency noise and stabilize the supply during output switching. For systems with multiple devices or sensitive analog sections, paralleling a 1μF capacitor is acceptable to improve low-frequency bypassing. Layout best practice mandates shortest possible trace lengths between capacitor pads and VCC/GND pins.
Is SN74HCT574DBRE4 pin-compatible with other 74HCT-series octal latches?
SN74HCT574DBRE4 shares the same 20-pin SSOP (DB) footprint and pin configuration with SN74HCT374DBR, but differs functionally: SN74HCT374DBR has a single OE input instead of dual OE (1OE/2OE). Other variants like SN74HCT273 (no 3-state) or SN74HCT573 (latch, not edge-triggered) are not pin-compatible. Always verify function table and timing before substitution.
SN74HCT574DBRE4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74HCT
- Package/Case:
- 20-SSOP (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Function:
- Standard
- Type:
- D-Type
- Output Type:
- Tri-State, Non-Inverted
- Number of Elements:
- 1
- Number of Bits per Element:
- 8
- Clock Frequency:
- 40 MHz
- Max Propagation Delay @ V, Max CL:
- 47ns @ 5.5V, 150pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 6mA, 6mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Current - Quiescent (Iq):
- 8 µA
- Input Capacitance:
- 3 pF
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SSOP
SN74HCT574DBRE4 FAQ
1.How can I place an order for SN74HCT574DBRE4 through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74HCT574DBRE4 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 SN74HCT574DBRE4 reliable?
The price and inventory of SN74HCT574DBRE4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74HCT574DBRE4 is usually 5 days.
3.What payment methods are accepted for SN74HCT574DBRE4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74HCT574DBRE4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74HCT574DBRE4?
SN74HCT574DBRE4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74HCT574DBRE4 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 SN74HCT574DBRE4?
For technical support, including SN74HCT574DBRE4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74HCT574DBRE4 requirements.
6.How does Aetrix verify that SN74HCT574DBRE4 is sourced from the original manufacturer or authorized distributors?
All SN74HCT574DBRE4 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 SN74HCT574DBRE4 meets industry standards.
7.What is the process for return or replacement of SN74HCT574DBRE4?
All SN74HCT574DBRE4 units undergo pre-shipment inspection (PSI). If there is an issue with SN74HCT574DBRE4, 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 SN74HCT574DBRE4 part is unused and in its original packaging.
Return procedure for SN74HCT574DBRE4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74HCT574DBRE4 Tags
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