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Texas Instruments SN74ALS273DW
- Part No.:
- SN74ALS273DW
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
SN74ALS273DW.pdf
- Description:
- IC FF D-TYPE SNGL 8BIT 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:404
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Product details
Overview
SN74ALS273DW from Texas Instruments is an octal positive-edge-triggered D-type flip-flop with asynchronous clear, implemented in TTL-compatible ALS logic. It features eight independent D inputs, a common buffered clock (CLK), and a shared direct-clear (CLR) input, operating at 5 V supply with 35 MHz max clock frequency and 12 mA output drive capability. It is used in synchronous digital systems for data latching, register storage, and shift register stages.
For engineers reviewing the SN74ALS273DW datasheet, SN74ALS273DW pinout, SN74ALS273DW application, or SN74ALS273DW equivalent, key selection considerations include its 20-pin SOIC (DW) package, 0°C to 70°C temperature rating, TTL-level input thresholds, single-rail CMOS-compatible outputs, and compatibility with legacy 74-series bus-hold and control logic designs.
Technical Context
This device implements eight independent edge-triggered storage elements with synchronous data capture on the rising edge of CLK and immediate asynchronous reset via active-low CLR. Each flip-flop has dedicated D input and Q output, with no internal feedback or output enable - all outputs are always active (non-3-state).
The SN74ALS273DW uses Advanced Low-Power Schottky (ALS) bipolar technology, delivering higher speed and lower power than standard LS TTL while maintaining pin compatibility with SN74LS273. Its propagation delays (tPLH/tPHL ≤ 15 ns) and setup/hold times (tsu = 10 ns, th = 0 ns) are specified under 50 pF load and 5 V supply across 0°C–70°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | ALS TTL - ensures interoperability with 74LS/74F logic and defined noise margins at 5 V. |
| Supply Voltage | 4.5 V to 5.5 V - requires stable 5 V rail; not suitable for 3.3 V operation. |
| Max Clock Frequency | 35 MHz - supports high-speed register transfer in legacy microprocessor support circuits. |
| Output Drive | IOL = 24 mA / IOH = –2.6 mA - drives standard TTL loads directly without buffers. |
| Propagation Delay | tPLH ≤ 12 ns, tPHL ≤ 18 ns - enables tight timing budgets in synchronous state machines. |
| Operating Temperature | 0°C to 70°C - rated for commercial-grade industrial and computing applications. |
| Input Thresholds | VIL = 0.8 V, VIH = 2.0 V - compatible with TTL and CMOS 5 V logic families. |
Pinout & Package
SN74ALS273DW is housed in a 20-pin small-outline integrated circuit (SOIC) package (DW), 7.5 mm wide, with 1.27 mm pitch and 2.65 mm max height. Pin 1 is marked by a beveled corner or notch orientation per JEDEC MS-013.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CLR) | Asynchronous Clear Input | Active-low global reset - forces all Q outputs low regardless of CLK or D state. |
| 2–9 (1D–8D) | Data Inputs | Independent D inputs for each of eight flip-flops; sampled on CLK rising edge. |
| 10 (GND) | Ground Reference | Power return path for logic and output drivers; must be low-impedance. |
| 11–18 (1Q–8Q) | True Outputs | Non-inverted registered outputs; no complementary (Q̅) pins provided. |
| 19 (CLK) | Clock Input | Buffered positive-edge-triggered clock; triggers all eight flip-flops simultaneously. |
| 20 (VCC) | Supply Voltage | +5 V power pin; requires local 0.1 µF ceramic decoupling near package. |
Key Features
| Feature | Design Value |
|---|---|
| Octal D-type storage | Eight independent registers in one package reduce board space vs discrete flip-flops. |
| Direct-clear functionality | Single-pin asynchronous reset simplifies system initialization and fault recovery. |
| Buffered clock and clear | Internal buffering improves noise immunity and fanout capability for CLK/CLR signals. |
| TTL-compatible I/O levels | Interoperates with legacy 74LS, 74F, and microcontroller GPIOs without level-shifting. |
| ALS process technology | Delivers 35 MHz operation with ~20 mA typical ICC - optimized for speed/power tradeoff in 5 V systems. |
Applications
| Buffer/Storage Registers | Shift Registers |
|---|---|
Use Scenario: Holding parallel data from an 8-bit bus during CPU read/write cycles in embedded controllers. IC Role / Device Role / Timing Role: Data latch synchronizing asynchronous peripheral transfers to the processor clock domain. Use Value: Prevents metastability and ensures glitch-free sampling using controlled edge-triggered capture. | Use Scenario: Constructing serial-to-parallel or parallel-to-serial converters in test equipment and protocol interfaces. IC Role / Device Role / Timing Role: Core storage element cascaded with external feedback or multiplexing for bit-shift sequencing. Use Value: Enables deterministic 8-bit shift timing with predictable 12–18 ns propagation delay per stage. |
| Pattern Generators | Microprocessor Support Logic |
Use Scenario: Generating fixed test vectors or waveform sequences in automated test fixtures and logic analyzers. IC Role / Device Role / Timing Role: State-holding unit in finite-state machines that produce repeatable digital stimulus patterns. Use Value: Provides deterministic, jitter-free output transitions synchronized to system clock edges. | Use Scenario: Latching address/data strobes or generating chip-select timing in 8-bit microcomputer systems (e.g., Z80, 8085). IC Role / Device Role / Timing Role: Synchronization and hold register for control signals between CPU and memory/peripheral ICs. Use Value: Meets strict setup/hold requirements (tsu = 10 ns) for reliable interface timing at 35 MHz. |
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 |
|---|---|---|---|
| SN74LS273N | Slower max clock (30 MHz), higher ICC (~30 mA), same pinout and function. | Lower-speed legacy systems where ALS speed/power advantage is unnecessary. | Choose SN74LS273N only if existing design uses LS family and timing margin allows. |
| SN74HC273PW | CMOS-based, 2–6 V supply, 30 MHz max, 3-state outputs optional, different voltage thresholds. | Modern 3.3 V or mixed-voltage systems requiring lower power and wider VCC range. | Use SN74HC273PW when upgrading to CMOS logic or adding output enable control. |
Compared with SN74LS273N and SN74HC273PW, the SN74ALS273DW delivers superior speed-to-power ratio in 5 V TTL environments, retains full pin compatibility with LS273, and avoids CMOS-level translation overhead - making it optimal for performance-critical upgrades of legacy 74-series designs.
Availability
SN74ALS273DW is available at Aetrix Electronics and suitable for buffer/register storage, shift register construction, pattern generation, and microprocessor support logic requiring stable component supply across long-lifecycle industrial and computing platforms.
Supply support for SN74ALS273DW 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.
The SN74ALS273DW belongs to TI's legacy 74ALS logic family, designed specifically to replace 74LS devices with improved speed and reduced power consumption in 5 V digital control and data-path applications.
FAQ
What is the maximum clock frequency supported by the SN74ALS273DW?
The SN74ALS273DW supports a maximum clock frequency of 35 MHz under recommended operating conditions (VCC = 4.5 V to 5.5 V, CL = 50 pF, TA = 0°C to 70°C). This rating is verified per the SDAS218A datasheet switching characteristics table and reflects guaranteed timing performance across the commercial temperature range. Exceeding 35 MHz may result in setup/hold violations or metastability.
Does the SN74ALS273DW have 3-state outputs?
No, the SN74ALS273DW does not feature 3-state outputs. All eight Q outputs are always active (totem-pole) and lack output-enable (OE) control. This distinguishes it from variants like SN74ALS374 or SN74HC273 with tri-state capability. The SN74ALS273DW is intended for point-to-point or bus-driving applications where contention is managed externally.
What is the function of Pin 1 on the SN74ALS273DW?
Pin 1 of the SN74ALS273DW is the active-low asynchronous clear (CLR) input. When pulled low, it immediately forces all eight Q outputs to logic low, independent of the clock signal or D input states. This function is critical for system initialization, error recovery, and synchronous reset coordination in digital control logic using the SN74ALS273DW.
Can the SN74ALS273DW operate at 3.3 V?
No, the SN74ALS273DW is not rated for 3.3 V operation. Its absolute maximum supply voltage is 7 V, but the recommended operating range is strictly 4.5 V to 5.5 V. At 3.3 V, the ALS TTL circuitry will fail to meet VIH/VIL thresholds, resulting in undefined logic states, excessive propagation delay, or complete functional failure. Use SN74HC273 or SN74AHC273 for 3.3 V systems.
Is the SN74ALS273DW pin-compatible with the SN74LS273?
Yes, the SN74ALS273DW is fully pin-compatible with the SN74LS273 in the same SOIC (DW) or PDIP (N) packages. Both share identical pin assignments, electrical interface definitions, and functional behavior - including the same CLR, CLK, D, and Q pin locations and logic operation. This allows direct drop-in replacement to improve speed and reduce power without PCB layout changes.
SN74ALS273DW Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74ALS
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Function:
- Master Reset
- Type:
- D-Type
- Output Type:
- Non-Inverted
- Number of Elements:
- 1
- Number of Bits per Element:
- 8
- Clock Frequency:
- 35 MHz
- Max Propagation Delay @ V, Max CL:
- 15ns @ 5V, 50pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 2.6mA, 24mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Current - Quiescent (Iq):
- 20 mA
- Input Capacitance:
- -
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SOIC
SN74ALS273DW FAQ
1.How can I place an order for SN74ALS273DW through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ALS273DW 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 SN74ALS273DW reliable?
The price and inventory of SN74ALS273DW are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ALS273DW is usually 5 days.
3.What payment methods are accepted for SN74ALS273DW?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74ALS273DW transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74ALS273DW?
SN74ALS273DW orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74ALS273DW 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 SN74ALS273DW?
For technical support, including SN74ALS273DW datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ALS273DW requirements.
6.How does Aetrix verify that SN74ALS273DW is sourced from the original manufacturer or authorized distributors?
All SN74ALS273DW 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 SN74ALS273DW meets industry standards.
7.What is the process for return or replacement of SN74ALS273DW?
All SN74ALS273DW units undergo pre-shipment inspection (PSI). If there is an issue with SN74ALS273DW, 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 SN74ALS273DW part is unused and in its original packaging.
Return procedure for SN74ALS273DW:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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