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Texas Instruments SN74HC377NSR
- Part No.:
- SN74HC377NSR
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 20-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
SN74HC377NSR.pdf
- Description:
- IC FF D-TYPE SNGL 8BIT 20SO
- Quantity:
- Payment:
- Shipping:
Inventory:833
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Product details
Overview
SN74HC377NSR from Texas Instruments is a positive-edge-triggered octal D-type flip-flop with latched clock enable (CLKEN), operating across 2 V to 6 V. It provides eight independent single-rail storage elements, 12 ns typical propagation delay at 5 V, ±4-mA output drive, and 80-µA max ICC. It is used in synchronous data latching for industrial control registers and digital logic buffering.
For engineers reviewing the SN74HC377NSR datasheet, SN74HC377NSR pinout, SN74HC377NSR application, or SN74HC377NSR equivalent, key selection criteria include clock-enable latching behavior, 20-pin SO package thermal resistance (113.4°C/W), guaranteed setup/hold timing at 5 V, and compatibility with LSTTL load driving (up to 10 loads).
Technical Context
The SN74HC377NSR implements eight edge-triggered D flip-flops sharing one CLK and one latched CLKEN input - unlike the SN74HC273, which uses asynchronous clear. CLKEN is sampled on the falling edge of CLK and held internally to prevent false triggering during enable transitions.
Each flip-flop transfers D-input data to Q-output on the rising edge of CLK only when CLKEN is low. Inputs are CMOS-compatible with VIH/VIL thresholds defined per VCC (e.g., 3.15 V/1.35 V at 4.5 V), and outputs meet standard push-pull voltage levels (VOH ≥ 4.4 V, VOL ≤ 0.26 V at 4.5 V, IOL = 4 mA).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2 V to 6 V - supports mixed-voltage system interfacing and battery-powered operation down to 2 V. |
| Propagation Delay (tpd) | 12 ns typical at VCC = 5 V, CL = 50 pF - enables reliable operation up to 20 MHz clock frequency in synchronous logic paths. |
| Output Drive Strength | ±4 mA at VCC = 5 V - sufficient to directly drive 10 LSTTL inputs without buffer amplification. |
| Quiescent Current (ICC) | 80 µA max at VCC = 6 V - ensures ultra-low static power in always-on register stages. |
| Input Leakage Current | ±1 µA max - minimizes unintended current paths in high-impedance or battery-sensitive circuits. |
| Junction-to-Ambient θJA | 113.4°C/W (SO-20 package) - defines thermal derating limit for continuous operation at ambient temperatures up to 85°C. |
| Setup/Hold Time (tsu/th) | 25 ns / 5 ns at VCC = 4.5 V - constrains maximum data path skew before CLK edge in register-file timing closure. |
Pinout & Package
SOP-20 (NS) package: 15.00 mm × 5.30 mm body, 1.27 mm pitch, gull-wing leads, RoHS-compliant NIPDAU finish, moisture sensitivity level 1 (260°C peak reflow).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1–8 (D1–D8) | Data inputs | Asynchronous parallel data inputs; must be stable ≥25 ns before CLK↑ under 4.5 V operation. |
| 9 (GND) | Ground reference | Common return for all internal logic and output drivers; requires low-inductance connection to PCB ground plane. |
| 10 (CLK) | Clock input | Positive-edge-triggered master clock; transition rate limited by input rise/fall time (≤500 ns at 4.5 V). |
| 11 (CLKEN) | Clock enable control | Latched on falling CLK edge; low enables data capture on next rising CLK, high holds Q outputs unchanged. |
| 12–19 (Q1–Q8) | Registered outputs | True (non-inverted) outputs reflecting Dn state captured at prior enabled CLK↑; fan-out limited to 10 LSTTL loads. |
| 20 (VCC) | Power supply | Primary CMOS supply rail; requires local 0.1-µF ceramic bypass capacitor placed within 5 mm of pin. |
Key Features
| Feature | Design Value |
|---|---|
| Latched clock enable | CLKEN sampled on CLK↓ and held internally - eliminates metastability and spurious toggling during enable transitions. |
| Wide supply range | 2 V to 6 V operation - allows direct interface with 3.3 V microcontrollers and legacy 5 V systems without level shifters. |
| Low dynamic power | 30 pF typical power dissipation capacitance per flip-flop - reduces switching current and EMI in high-frequency register banks. |
| CMOS input compatibility | VIH = 3.15 V / VIL = 1.35 V at 4.5 V - ensures robust noise margin (>1.2 V) against rail-to-rail digital noise in industrial environments. |
| Output short-circuit tolerance | ±25 mA continuous output current rating - withstands momentary bus contention or accidental shorts without latch-up. |
Applications
| Industrial PLC Register Bank | Digital Audio Sample Buffer |
|---|---|
Use Scenario: Storing I/O status bits from sensor arrays in programmable logic controllers with deterministic update timing. IC Role / Device Role / Timing Role: Synchronous 8-bit latch providing glitch-free state capture aligned to system clock edges. Use Value: Latched CLKEN prevents partial updates during enable assertion/deassertion, ensuring atomic register writes in real-time control loops. | Use Scenario: Holding parallel audio sample words between ADC capture and DSP processing stages in embedded audio codecs. IC Role / Device Role / Timing Role: Edge-triggered data staging element synchronizing multi-channel PCM data to a common frame clock. Use Value: 12 ns tpd and 25 ns tsu support 20+ MHz sampling rates while maintaining setup margin for FPGA-based timing closure. |
| Test Equipment Pattern Generator | Automotive Body Control Module |
Use Scenario: Generating repeatable stimulus patterns for IC functional testing using programmable logic sequencers. IC Role / Device Role / Timing Role: Octal parallel output register controlling TTL-level test vectors on 8-bit bus interfaces. Use Value: ±4-mA drive strength directly sources/sinks LSTTL loads, eliminating external buffers and reducing BOM count. | Use Scenario: Latching door lock actuator commands and window position feedback in 12 V automotive subsystems with 5 V logic rails. IC Role / Device Role / Timing Role: Isolated storage element decoupling microcontroller GPIO timing from mechanical actuator response delays. Use Value: 2 V to 6 V supply range accommodates brown-out conditions down to 2.5 V while retaining valid register state. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal D-type flip-flop applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HC273N | Shares same SO-20 footprint and 2–6 V supply, but uses asynchronous active-low CLR instead of latched CLKEN. | Requires external synchronization of clear signals; unsuitable where enable must be sampled concurrently with clock edge. | Select SN74HC273N only if system design already implements synchronized reset distribution and does not require CLKEN latching. |
| 74LVX377M | Lower voltage range (2.0–3.6 V), 3.3 V optimized; 10 ns tpd at 3.3 V; higher ICC (120 µA max) and lower drive (±2.6 mA). | Designed for 3.3 V-only systems; incompatible with 5 V logic domains without translation. | Choose 74LVX377M for cost-sensitive, low-voltage portable designs where 5 V tolerance is unnecessary. |
Compared with SN74HC273N, SN74HC377NSR trades asynchronous reset flexibility for deterministic enable timing; compared with 74LVX377M, it offers broader voltage interoperability and stronger drive at the expense of slightly higher static current - making SN74HC377NSR optimal for mixed-voltage industrial control register banks.
Availability
SN74HC377NSR is available at Aetrix Electronics and suitable for industrial PLC register banks, digital audio sample buffering, test equipment pattern generation, and automotive body control modules requiring stable component supply across extended temperature ranges (–40°C to +85°C).
Supply support for SN74HC377NSR 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 for industrial, automotive, and personal electronics markets.
The SN74HC377NSR belongs to TI's 74HC logic family, engineered for high-noise-immunity, low-power, pin-compatible replacement of legacy TTL in synchronous digital systems requiring precise edge-triggered storage.
FAQ
What is the maximum clock frequency supported by SN74HC377NSR at 5 V?
The SN74HC377NSR supports a maximum clock frequency of 20 MHz at VCC = 4.5 V and TA = 25°C, based on its 25 ns minimum pulse width (tW) and 12 ns typical propagation delay. At full 5 V operation, timing margins align with this rating, enabling reliable use in 20-MHz synchronous logic chains when layout and loading comply with datasheet guidelines.
Does SN74HC377NSR require external pull-up or pull-down resistors on unused inputs?
Yes - all unused inputs of SN74HC377NSR must be tied to VCC or GND to prevent floating states that cause increased ICC, erratic outputs, or ESD susceptibility. The device has no internal termination; TI recommends hard-wiring unused D or CLKEN pins to a defined rail per SCBA004 application report guidance.
How does the latched CLKEN function differ from standard clock enable in SN74HC377NSR?
In SN74HC377NSR, CLKEN is latched on the falling edge of CLK and held until the next falling edge - preventing race conditions during enable transitions. Unlike combinational enables, this ensures data is only captured on rising CLK when CLKEN was low *at the prior falling CLK*, eliminating false triggers from asynchronous enable changes.
Can SN74HC377NSR drive LED indicators directly?
No - SN74HC377NSR is not rated for direct LED driving. Its ±4-mA output drive at 5 V is insufficient for typical indicator LEDs (requiring 10–20 mA). Use an external transistor or dedicated LED driver; connecting LEDs directly risks exceeding absolute maximum output current (±25 mA) and degrading VOL/VOH specs over time.
Is SN74HC377NSR pin-compatible with SN74HC377N or SN74HC377DWR?
Yes - SN74HC377NSR (SO-20), SN74HC377N (PDIP-20), and SN74HC377DWR (SOIC-20) share identical pinout, electrical specifications, and logic functionality. Only package dimensions, thermal resistance (θJA = 113.4°C/W for NS vs. 84.6°C/W for N), and mounting method differ - allowing drop-in replacement where board layout and thermal constraints permit.
SN74HC377NSR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74HC
- Package/Case:
- 20-SOIC (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Standard
- Type:
- D-Type
- Output Type:
- Non-Inverted
- Number of Elements:
- 1
- Number of Bits per Element:
- 8
- Clock Frequency:
- 64 MHz
- Max Propagation Delay @ V, Max CL:
- 27ns @ 6V, 50pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 5.2mA, 5.2mA
- Voltage - Supply:
- 2V ~ 6V
- 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-SO
SN74HC377NSR FAQ
1.How can I place an order for SN74HC377NSR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74HC377NSR 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 SN74HC377NSR reliable?
The price and inventory of SN74HC377NSR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74HC377NSR is usually 5 days.
3.What payment methods are accepted for SN74HC377NSR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74HC377NSR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74HC377NSR?
SN74HC377NSR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74HC377NSR 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 SN74HC377NSR?
For technical support, including SN74HC377NSR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74HC377NSR requirements.
6.How does Aetrix verify that SN74HC377NSR is sourced from the original manufacturer or authorized distributors?
All SN74HC377NSR 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 SN74HC377NSR meets industry standards.
7.What is the process for return or replacement of SN74HC377NSR?
All SN74HC377NSR units undergo pre-shipment inspection (PSI). If there is an issue with SN74HC377NSR, 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 SN74HC377NSR part is unused and in its original packaging.
Return procedure for SN74HC377NSR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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