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Texas Instruments SN74ALS273DWR
- Part No.:
- SN74ALS273DWR
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
SN74ALS273DWR.pdf
- Description:
- IC FF D-TYPE SNGL 8BIT 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:917
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Product details
Overview
SN74ALS273DWR from Texas Instruments is an octal positive-edge-triggered D-type flip-flop with asynchronous clear, implemented in ALS TTL logic. It features eight independent D inputs, single-rail Q outputs, buffered clock and direct-clear inputs, and operates at 5 V supply over 0°C to 70°C. It is used in synchronous digital systems for data latching and register staging.
For engineers reviewing the SN74ALS273DWR datasheet, SN74ALS273DWR pinout, SN74ALS273DWR application, or SN74ALS273DWR equivalent, this device serves as a legacy-compatible, high-speed storage element in industrial control logic, bus interface buffering, and pattern generation circuits requiring deterministic edge-triggered behavior and guaranteed setup/hold timing.
Technical Context
This device implements eight identical D-type flip-flops sharing a common clock (CLK) and asynchronous clear (CLR) input. Each flip-flop transfers its D-input state to the Q-output on the positive-going edge of CLK, provided setup time (10 ns) and hold time (0 ns) are met. CLR overrides clock action and forces all Q outputs low asynchronously.
The SN74ALS273DWR uses bipolar ALS (Advanced Low-Power Schottky) TTL technology, delivering 35 MHz maximum clock frequency, 24 mA low-level output drive, and 2.4 V minimum VOH at 12 mA load. Its propagation delays range from 2 ns (tPLH, CLK→Q) to 18 ns (tPHL, CLK→Q) under standard load conditions (CL = 50 pF, RL = 500 Ω).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | ALS TTL - enables interoperability with 74LS/74AS families and supports mixed-logic system integration. |
| Supply Voltage | 4.5 V to 5.5 V - ensures stable operation across standard 5 V rail tolerances without regulation overhead. |
| Max Clock Frequency | 35 MHz - supports high-throughput data capture in legacy microprocessor address/data latch applications. |
| Output Drive | 24 mA sink (IOL), –2.6 mA source (IOH) - drives multiple TTL inputs or small LED indicators directly. |
| Propagation Delay | 2–18 ns (CLK→Q) - guarantees tight timing margins in synchronous pipeline stages and state-machine registers. |
| Operating Temperature | 0°C to 70°C - qualified for commercial-grade embedded systems including instrumentation and peripheral controllers. |
| Setup/Hold Time | tsu = 10 ns, th = 0 ns - simplifies timing closure with minimal external delay compensation required. |
Pinout & Package
SN74ALS273DWR is housed in a 20-pin SOIC (DW) package, 7.5 mm wide, 12.8 mm long, 2.65 mm max height, with 1.27 mm pitch and RoHS-compliant NiPdAu lead finish. Pin 1 is located in Quadrant Q1 per tape-and-reel orientation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | CLR | Asynchronous active-low clear - resets all eight Q outputs to logic low regardless of clock state. |
| 2–9 | 1D–8D | Independent data inputs - each controls corresponding flip-flop's next-state value on CLK edge. |
| 10 | GND | Ground reference - provides return path for all internal logic and output currents. |
| 11–18 | 1Q–8Q | Non-inverted registered outputs - reflect stored D-input values after CLK edge, with TTL-compatible voltage levels. |
| 19 | CLK | Positive-edge-triggered clock - samples all D inputs simultaneously on rising transition. |
| 20 | VCC | Power supply - supplies +5 V to internal ALS circuitry and output drivers. |
Key Features
| Feature | Design Value |
|---|---|
| Octal D-type architecture | Enables compact 8-bit register implementation without external gating or cascading logic. |
| Direct-clear (CLR) input | Allows global reset of all outputs in one cycle - critical for initialization and fault recovery in control sequencers. |
| Buffered clock and clear inputs | Reduces fan-out loading and improves noise immunity compared to unbuffered TTL variants. |
| Single-rail TTL outputs | Eliminates need for external pull-ups or level-shifting when interfacing with standard 74-series logic. |
| ALS process technology | Delivers 3× speed improvement over standard LS TTL while maintaining compatible power consumption (~29 mA ICCL). |
Applications
| Buffer/Storage Registers | Shift Registers |
|---|---|
|
Use Scenario: Holding parallel data from a microprocessor data bus during memory read/write cycles. IC Role / Device Role / Timing Role: Synchronous latch that captures and holds 8-bit data on CLK edge, isolating bus activity from downstream logic. Use Value: Prevents bus contention and enables pipelined execution by decoupling processor timing from slower peripherals. |
Use Scenario: Constructing serial-to-parallel or parallel-to-serial converters using daisy-chained devices. IC Role / Device Role / Timing Role: Edge-triggered stage in multi-device shift chain, where Q outputs feed adjacent D inputs. Use Value: Enables deterministic bit-shift timing with predictable 2–18 ns propagation, supporting reliable 35 MHz serial throughput. |
| Pattern Generators | Industrial Control Logic |
|
Use Scenario: Generating fixed test sequences (e.g., walking 1s, checkerboard) for PCB functional testing. IC Role / Device Role / Timing Role: State-holding element in combinational feedback loops or counter-based waveform engines. Use Value: Provides glitch-free, edge-aligned output transitions essential for reproducible stimulus patterns. |
Use Scenario: Latching sensor status bits (e.g., limit switches, encoder states) in PLC I/O modules. IC Role / Device Role / Timing Role: Input register synchronizing asynchronous field signals to the controller's clock domain. Use Value: Eliminates metastability risk via guaranteed 10 ns setup time and robust ALS noise margin (>0.4 V). |
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 | Lower speed (30 MHz max), higher power (ICCL ≈ 40 mA), standard LS TTL - no ALS optimization. | Suitable for cost-sensitive, lower-frequency designs where 35 MHz headroom is unnecessary. | Choose SN74LS273N only if legacy LS compatibility is prioritized over speed/power trade-off. |
| SN74HC273PW | CMOS technology, 2–6 V supply, 25 MHz max, near-zero static current, but requires level translation for TTL interfaces. | Better for battery-powered or mixed-voltage systems; incompatible with direct TTL fan-out without buffers. | Prefer SN74HC273PW when supply flexibility and ultra-low quiescent power outweigh TTL interoperability needs. |
Compared with SN74ALS273DWR, SN74LS273N trades speed and efficiency for broader legacy adoption, while SN74HC273PW shifts to CMOS advantages at the cost of native TTL signal integrity - neither is pin-compatible, and both require layout or interface adjustments.
Availability
SN74ALS273DWR is available at Aetrix Electronics and suitable for industrial control logic, legacy system repair, and test equipment design requiring stable component supply and long-term obsolescence management.
Supply support for SN74ALS273DWR 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 SN74ALS273DWR belongs to TI's legacy 74ALS logic family, designed specifically for high-speed, low-power TTL-compatible digital systems where timing predictability and direct interfacing with older microprocessor buses were critical.
FAQ
What is the maximum clock frequency supported by the SN74ALS273DWR?
The SN74ALS273DWR 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 in the switching characteristics table of the official datasheet and reflects guaranteed timing performance across the full commercial temperature range. The SN74ALS273DWR achieves this speed through ALS TTL process enhancements over standard LS logic.
Does the SN74ALS273DWR have 3-state outputs?
No, the SN74ALS273DWR does not feature 3-state outputs - it provides standard totem-pole TTL outputs with active high and active low drive capability. All eight Q outputs are always driven (no high-impedance mode), as confirmed by the logic diagram, electrical characteristics, and absence of output-enable (OE) functionality in the function table. This distinguishes the SN74ALS273DWR from variants like the SN74ALS374, which include tri-state control.
What is the purpose of the CLR input on the SN74ALS273DWR?
The CLR (clear) input on the SN74ALS273DWR is an asynchronous, active-low signal that forces all eight Q outputs to logic low independently of the clock. When asserted (low), it overrides any ongoing clock activity and immediately resets stored states. This function is essential for system initialization, error recovery, and synchronized startup sequences. The SN74ALS273DWR's CLR is buffered, improving noise immunity and fan-out capability compared to unbuffered alternatives.
Can the SN74ALS273DWR operate at 3.3 V supply voltage?
No, the SN74ALS273DWR is not rated for 3.3 V operation. Its recommended supply voltage range is strictly 4.5 V to 5.5 V, and absolute maximum VCC is 7 V. Operation below 4.5 V risks violating VIH/VIL thresholds, degrading noise margin, and causing unreliable switching - confirmed by the "recommended operating conditions" table. For 3.3 V systems, consider CMOS alternatives such as SN74LVC273, not the SN74ALS273DWR.
Is the SN74ALS273DWR pin-compatible with the SN74LS273N?
Yes, the SN74ALS273DWR and SN74LS273N share identical pinouts and package footprints (20-pin SOIC DW vs. 20-pin PDIP N), enabling direct board-level substitution in many cases. Both follow the same functional pin mapping: CLR on pin 1, D inputs on pins 2–9, GND on pin 10, Q outputs on pins 11–18, CLK on pin 19, and VCC on pin 20. However, due to differing AC characteristics and drive strength, timing validation is required when replacing SN74LS273N with SN74ALS273DWR in existing designs.
SN74ALS273DWR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74ALS
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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
SN74ALS273DWR FAQ
1.How can I place an order for SN74ALS273DWR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ALS273DWR 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 SN74ALS273DWR reliable?
The price and inventory of SN74ALS273DWR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ALS273DWR is usually 5 days.
3.What payment methods are accepted for SN74ALS273DWR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74ALS273DWR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74ALS273DWR?
SN74ALS273DWR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74ALS273DWR 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 SN74ALS273DWR?
For technical support, including SN74ALS273DWR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ALS273DWR requirements.
6.How does Aetrix verify that SN74ALS273DWR is sourced from the original manufacturer or authorized distributors?
All SN74ALS273DWR 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 SN74ALS273DWR meets industry standards.
7.What is the process for return or replacement of SN74ALS273DWR?
All SN74ALS273DWR units undergo pre-shipment inspection (PSI). If there is an issue with SN74ALS273DWR, 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 SN74ALS273DWR part is unused and in its original packaging.
Return procedure for SN74ALS273DWR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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