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Texas Instruments SN74HCT377DW
- Part No.:
- SN74HCT377DW
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
SN74HCT377DW.pdf
- Description:
- IC FF D-TYPE SNGL 8BIT 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:475
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Product details
Overview
SN74HCT377DW from Texas Instruments is an octal positive-edge-triggered D-type flip-flop with latched clock enable (CLKEN), operating at 4.5 V to 5.5 V, delivering 12 ns typical propagation delay, ±4-mA output drive at 5 V, and low 80-µA max ICC. It serves as a synchronous storage register in digital control logic, data buffering, and pattern generation circuits.
For engineers reviewing the SN74HCT377DW datasheet, SN74HCT377DW pinout, SN74HCT377DW application, or SN74HCT377DW equivalent, this page provides verified functional identity, SOIC-20 package mapping, timing behavior under CL = 50 pF, TTL-compatible input thresholds, and validated alternative options for register-level logic replacement.
Technical Context
The SN74HCT377DW implements eight independent D-type flip-flops sharing a common clock (CLK) and latched clock-enable (CLKEN) input. CLKEN is sampled on the falling edge of CLK to prevent false triggering during asynchronous transitions, ensuring robust synchronization in noisy environments.
Each flip-flop transfers data from D to Q on the positive-going edge of CLK only when CLKEN is low. Inputs meet TTL voltage compatibility (VIH = 2 V min, VIL = 0.8 V max), and outputs drive up to 10 LSTTL loads with VOL ≤ 0.33 V at IOL = 4 mA and VOH ≥ 3.7 V at IOH = –4 mA.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5 V to 5.5 V - Ensures stable operation across standard 5-V TTL/CMOS mixed-signal systems. |
| Propagation Delay (tpd) | 12 ns typical at VCC = 5.5 V, CL = 50 pF - Enables reliable 22-MHz clock operation in synchronous logic chains. |
| Output Drive | ±4 mA at 5 V - Sufficient to directly interface with legacy LSTTL inputs without level-shifting or buffering. |
| Input Current (II) | ±1 µA max - Minimizes loading on upstream drivers and supports high-fanout bus designs. |
| Power Consumption (ICC) | 80 µA max - Supports low-static-power system states while maintaining full-speed functionality. |
| Setup/Hold Times | tsu = 14 ns, th = 3 ns at VCC = 5.5 V - Defines minimum data stability window before and after CLK edge for reliable capture. |
| Operating Temperature | –40°C to +85°C - Qualified for industrial-grade embedded control and automation applications. |
Pinout & Package
SN74HCT377DW is housed in a 20-pin SOIC (DW) package, 7.5 mm wide, 12.8 mm long, with 1.27 mm pitch and maximum height of 2.65 mm. Pin 1 is located at the top-left corner with notch or beveled edge marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | CLKEN | Latched clock-enable input; low enables clocking, high holds Q outputs unchanged. |
| 2–9 | D1–D8 | Data inputs for each of eight flip-flops; sampled on CLK↑ when CLKEN = L. |
| 10 | GND | Ground reference for all internal logic and output drivers. |
| 11–18 | Q1–Q8 | Registered outputs; retain state between enabled clock edges. |
| 19 | VCC | Positive supply rail (4.5–5.5 V); powers all logic and output stages. |
| 20 | CLK | Positive-edge-triggered clock input; controls synchronous transfer of D to Q. |
Key Features
| Feature | Design Value |
|---|---|
| Latched CLKEN | Prevents metastability-induced false clocking by sampling CLKEN synchronously on CLK↓, not asynchronously. |
| TTL-Compatible Inputs | VIH = 2 V min and VIL = 0.8 V max allow direct connection to 5-V TTL outputs without pull-ups or level shifters. |
| Single-Rail Outputs | All Q outputs share VCC/GND rails - simplifies PCB routing and eliminates need for dual-supply decoupling. |
| Low ICC Standby | 80 µA max ICC ensures minimal power draw during idle periods in battery-backed or energy-sensitive systems. |
| 10-LSTTL Load Drive | Guaranteed fanout capability reduces need for external buffer stages in register-to-bus interfacing. |
Applications
| Industrial Control Registers | Microcontroller I/O Expansion |
|---|---|
|
Use Scenario: Holding status bits from PLC sensor inputs before parallel read by a main controller. IC Role / Device Role / Timing Role: Synchronous storage register capturing 8-bit parallel data on rising CLK edge under gated CLKEN control. Use Value: Eliminates race conditions during multi-cycle bus reads by freezing sampled values until next valid clock cycle. |
Use Scenario: Extending GPIO count of an MCU with limited native parallel I/O for LED matrix or relay bank control. IC Role / Device Role / Timing Role: Output latch providing glitch-free 8-bit parallel output synchronized to MCU clock domain. Use Value: Enables deterministic update timing with no output glitches during partial writes, critical for driving electromechanical loads. |
| Test Equipment Pattern Generation | Digital Audio Data Buffering |
|
Use Scenario: Generating repeatable stimulus patterns for IC functional testing using fixed or sequenced D-input vectors. IC Role / Device Role / Timing Role: Clock-controlled pattern register stepping through predefined bit sequences on each CLK↑. Use Value: Provides precise, jitter-free waveform edges due to 12 ns tpd and tight setup/hold margins, supporting >20 MHz test clocks. |
Use Scenario: Temporarily storing 8-bit audio sample words from ADC before serial transmission via SPI/I²S interface. IC Role / Device Role / Timing Role: Intermediary parallel latch isolating ADC conversion timing from variable serial transmit latency. Use Value: Prevents sample loss during serial bus contention by holding data stable until transmit channel becomes available. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal D-type register applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HCT273DW | Lacks latched CLKEN; uses active-low asynchronous clear (CLR̅) instead of clock enable. | Requires external gating logic to replicate CLKEN functionality; less suitable for shared-clock multi-register systems. | Select when reset-dominant behavior is needed or when CLKEN latching is unnecessary. |
| 74ACT377PC | Higher speed (tpd ≈ 8 ns), 5-V only, higher ICC (2 mA typ), non-latched clock enable. | Delivers faster throughput but consumes more power and lacks false-clocking immunity of SN74HCT377DW's latched CLKEN. | Select for performance-critical paths where power budget allows and CLKEN transition noise is controlled externally. |
Compared with SN74HCT273DW and 74ACT377PC, the SN74HCT377DW uniquely combines latched clock-enable immunity, 5-V TTL compatibility, and ultra-low standby current-making it optimal for industrial register interfaces requiring noise resilience and energy efficiency.
Availability
SN74HCT377DW is available at Aetrix Electronics and suitable for industrial control registers, microcontroller I/O expansion, test equipment pattern generation, and digital audio data buffering requiring stable component supply and long-term sourcing continuity.
Supply support for SN74HCT377DW 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 over 50 years of innovation in industrial, automotive, and communications markets.
The SN74HCT377DW belongs to TI's HCT logic family, designed specifically for 5-V TTL-compatible digital systems requiring low power, noise-immune clock control, and drop-in replacement capability for legacy 74-series devices.
FAQ
What is the function of the CLKEN pin on the SN74HCT377DW?
The CLKEN pin on the SN74HCT377DW is a latched clock-enable input that must be low to allow data transfer from D to Q on the next positive CLK edge. It is sampled synchronously on the falling edge of CLK, preventing false triggering from asynchronous transitions - a key differentiator from non-latched enable schemes used in similar devices like the SN74HCT273DW. This behavior is explicitly confirmed in the logic diagram and function table of the SN74HCT377DW datasheet.
Does the SN74HCT377DW support mixed-voltage operation below 4.5 V?
No, the SN74HCT377DW does not support operation below 4.5 V. Its recommended operating conditions specify a strict 4.5 V to 5.5 V supply range, and electrical characteristics such as VOH, VOL, and tpd are only guaranteed within that window. Operation at 3.3 V is not supported - for lower-voltage systems, consider the SN74LVC377A or similar LVC-family alternatives explicitly rated for 3.3-V operation.
Can the SN74HCT377DW drive standard TTL loads directly?
Yes, the SN74HCT377DW can drive up to 10 LSTTL loads directly. Its output drive strength is specified as ±4 mA at 5 V, with VOL ≤ 0.33 V at IOL = 4 mA and VOH ≥ 3.7 V at IOH = –4 mA - meeting and exceeding standard LSTTL input requirements (VIL ≤ 0.8 V, VIH ≥ 2.0 V). This eliminates the need for external buffers in most 5-V TTL/CMOS interfacing scenarios.
What is the maximum clock frequency supported by the SN74HCT377DW?
The SN74HCT377DW supports a maximum clock frequency of 22 MHz at VCC = 5.5 V and TA = 25°C with CL = 50 pF, as specified in the switching characteristics table. At VCC = 4.5 V, the maximum frequency drops to 20 MHz. These values assume proper signal integrity, layout, and load conditions - real-world operation may require derating based on board-level parasitics and temperature extremes.
Is the SN74HCT377DW pin-compatible with other 20-pin SOIC octal flip-flops?
The SN74HCT377DW shares the same 20-pin SOIC (DW) mechanical footprint and pinout as SN74HCT273DW and SN74LS377N, but functional pin assignments differ - notably, pin 1 is CLKEN (not CLR̅) and pins 11–18 are Q1–Q8 outputs (same location). While physically mountable in identical footprints, electrical and functional compatibility requires verification of enable/clear logic, timing, and drive strength per application.
SN74HCT377DW Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74HCT
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Function:
- Standard
- Type:
- D-Type
- Output Type:
- Non-Inverted
- Number of Elements:
- 1
- Number of Bits per Element:
- 8
- Clock Frequency:
- 37 MHz
- Max Propagation Delay @ V, Max CL:
- 28ns @ 5.5V, 50pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 4mA, 4mA
- 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-SOIC
SN74HCT377DW FAQ
1.How can I place an order for SN74HCT377DW through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74HCT377DW 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 SN74HCT377DW reliable?
The price and inventory of SN74HCT377DW are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74HCT377DW is usually 5 days.
3.What payment methods are accepted for SN74HCT377DW?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74HCT377DW transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74HCT377DW?
SN74HCT377DW orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74HCT377DW 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 SN74HCT377DW?
For technical support, including SN74HCT377DW datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74HCT377DW requirements.
6.How does Aetrix verify that SN74HCT377DW is sourced from the original manufacturer or authorized distributors?
All SN74HCT377DW 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 SN74HCT377DW meets industry standards.
7.What is the process for return or replacement of SN74HCT377DW?
All SN74HCT377DW units undergo pre-shipment inspection (PSI). If there is an issue with SN74HCT377DW, 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 SN74HCT377DW part is unused and in its original packaging.
Return procedure for SN74HCT377DW:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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