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STMicroelectronics 74ACT273TTR
- Part No.:
- 74ACT273TTR
- Manufacturer:
- STMicroelectronics
- Category:
- Flip Flops
- Package:
- 20-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
74ACT273TTR.pdf
- Description:
- IC FF D-TYPE SNGL 8BIT 20TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,087
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Product details
Overview
74ACT273TTR from STMicroelectronics is an octal D-type flip-flop with asynchronous clear, designed for high-speed synchronous data latching in TTL- and CMOS-compatible digital systems. It features 190 MHz max clock frequency (typ.), 24 mA symmetrical output drive, 4.5–5.5 V operating range, and 2 kV ESD protection. It is used in address/data register staging, bus interface synchronization, and clock-domain crossing in industrial control logic.
For engineers reviewing the 74ACT273TTR datasheet, 74ACT273TTR pinout, 74ACT273TTR application, or 74ACT273TTR equivalent, key selection criteria include propagation delay matching (tPLH/tPHL ≈ 4 ns), 50 Ω transmission line drive capability, asynchronous clear timing (tWL = 4.0 ns min), and TSSOP-20 thermal and layout compatibility in space-constrained PCBs.
Technical Context
The 74ACT273TTR implements eight edge-triggered D flip-flops sharing a common clock and active-low asynchronous clear. All inputs are TTL-compatible (VIH ≥ 2.0 V, VIL ≤ 0.8 V), enabling direct interfacing with legacy 74LS and 74F logic without level shifters.
Its C2MOS sub-micron process delivers balanced tPLH/tPHL propagation delays (≤9.0 ns over temperature), symmetrical ±24 mA output sourcing/sinking, and low ICC of 4 µA (max) at 25°C - supporting low-static-power operation in always-on control registers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Max Clock Frequency | 190 MHz (typ.) at VCC = 5 V - enables sub-5.3 ns clock period timing in high-throughput register files |
| Propagation Delay (CLK→Q) | 4.0 ns (max, TA = −40 to +85°C) - ensures tight setup/hold margin for 100+ MHz system clocks |
| Output Drive Strength | ±24 mA (min) - directly drives 50 Ω transmission lines without external buffers |
| Supply Voltage Range | 4.5 V to 5.5 V - compatible with regulated 5 V rails and tolerates ±10% variation |
| Input Thresholds | VIH ≥ 2.0 V, VIL ≤ 0.8 V - guarantees interoperability with TTL, 74LS, and 74F families |
| ESD Protection | 2 kV HBM - meets IEC 61000-4-2 Level 2 for board-level robustness in industrial environments |
Pinout & Package
TSSOP-20 package: 6.5 mm × 4.4 mm body, 0.65 mm pitch, thin-profile surface-mount with exposed pad not present. RoHS-compliant, lead-free finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | CLEAR | Asynchronous active-low reset - forces all Q outputs low independent of clock or D inputs |
| 2,5,6,9,12,15,16,19 | Q0–Q7 | True outputs of D flip-flops - latch and hold D-input state on rising clock edge |
| 3,4,7,8,13,14,17,18 | D0–D7 | Data inputs - sampled only on positive clock transition; unaffected by CLEAR until next clock |
| 11 | CLOCK | Rising-edge-triggered clock - initiates synchronous capture of D inputs to Q outputs |
| 10 | GND | Signal and power ground reference - must be low-inductance connection for noise immunity |
| 20 | VCC | Positive supply - requires local 0.1 µF ceramic decoupling adjacent to pin |
Key Features
| Feature | Design Value |
|---|---|
| Pin- and function-compatible with 74LS273/74F273 | Drop-in replacement in legacy designs without PCB or firmware changes |
| 50 Ω transmission line driving | Eliminates need for external series termination resistors in point-to-point routing |
| Balanced tPLH/tPHL delays | Reduces clock skew-induced metastability risk in multi-bit register banks |
| Improved latch-up immunity | Withstands transient overvoltage events per JEDEC JESD78 Class II without destructive failure |
Applications
| Industrial PLC I/O Register | Legacy Bus Interface Buffer |
|---|---|
Use Scenario: Latching parallel sensor input data from 8-bit ADCs or opto-isolated field inputs into a microcontroller's memory-mapped I/O space. IC Role / Device Role / Timing Role: Synchronous data register holding sampled values until CPU read cycle; CLEAR resets all channels on fault condition. Use Value: 4.0 ns max propagation delay ensures deterministic sampling alignment across all 8 bits under 100 MHz bus clocks. | Use Scenario: Interfacing a modern FPGA-based controller with legacy 74LS TTL peripheral buses (e.g., ISA-style expansion). IC Role / Device Role / Timing Role: Level-shifting and timing-synchronized data staging between 3.3 V FPGA I/O and 5 V TTL peripherals. Use Value: TTL-compatible VIH/VIL thresholds and 24 mA drive eliminate external translators while maintaining signal integrity over 15 cm traces. |
| Motor Control State Register | Test Equipment Pattern Generator |
Use Scenario: Holding real-time PWM enable/disable states for 8 independent motor phases in a servo drive module. IC Role / Device Role / Timing Role: Safety-critical register storing commanded actuator states; asynchronous CLEAR provides hardware-initiated emergency stop. Use Value: 2 kV ESD rating and −55°C to +125°C operating range ensure reliability in electrically noisy, thermally demanding motor cabinets. | Use Scenario: Generating precise, repeatable 8-bit stimulus patterns for IC functional testing in ATE systems. IC Role / Device Role / Timing Role: High-fidelity pattern storage element synchronized to tester master clock with minimal jitter accumulation. Use Value: 190 MHz max clock frequency supports >100 MHz pattern rates, and matched tPLH/tPHL minimizes bit-to-bit skew in generated waveforms. |
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 |
|---|---|---|---|
| SN74ACT273PW | TSSOP-20, identical AC/DC specs, same 2 kV ESD, but TI packaging marking differs | No functional difference; validated for same industrial register and bus interface roles | Select when dual-sourcing required or TI logistics preferred |
| 74VHC273FT | Lower drive (±8 mA), wider VCC (2–5.5 V), slower fMAX (110 MHz), no 50 Ω line drive spec | Suitable for low-power, mixed-voltage systems but not for high-speed transmission line interfaces | Choose only if supply voltage flexibility or ultra-low ICC (<1 µA) outweighs speed and drive needs |
Compared with SN74ACT273PW and 74VHC273FT, the 74ACT273TTR uniquely combines 190 MHz speed, ±24 mA drive, and guaranteed 50 Ω line driving - making it the only option among the three for noise-immune, high-frequency register staging in industrial backplanes.
Availability
74ACT273TTR is available at Aetrix Electronics and suitable for industrial PLC I/O modules, legacy bus interface adapters, motor control state registers, and ATE pattern generators requiring stable component supply across extended temperature and long production lifecycles.
Supply support for 74ACT273TTR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, specializing in automotive, industrial, and power management ICs with vertical manufacturing and broad analog/digital portfolio.
The 74ACT series targets high-speed, TTL-compatible logic replacement in industrial and telecom infrastructure - emphasizing robustness, timing precision, and drop-in compatibility with legacy 74xx families.
FAQ
Is the 74ACT273TTR pin-compatible with the 74LS273?
Yes, the 74ACT273TTR is fully pin- and function-compatible with the 74LS273, including identical pin numbering, D/Q mapping, and asynchronous CLEAR behavior. Its TTL-compatible input thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V) and 5 V supply requirement ensure direct substitution without circuit modification.
What is the minimum pulse width required on the CLEAR input?
The minimum CLEAR pulse width is 4.0 ns (max) over the full operating temperature range (−55°C to +125°C) at VCC = 5.0 V. This specification ensures reliable reset assertion even under fast transient conditions in high-speed control loops.
Does the 74ACT273TTR support hot insertion or live insertion?
No, the 74ACT273TTR does not support hot insertion. Its absolute maximum ratings specify VI and VO limits relative to VCC/GND, and no current-limiting or power-up sequencing features are included. Live insertion requires external protection circuitry and is not guaranteed by device specifications.
Can the 74ACT273TTR operate reliably at 3.3 V supply?
No - the 74ACT273TTR is specified only for 4.5 V to 5.5 V operation. At 3.3 V, VIH/VIL thresholds become non-compliant, propagation delays increase significantly, and output drive falls below 24 mA. For 3.3 V systems, consider the 74LVC273 or 74ALVC273 instead.
74ACT273TTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- 74ACT
- Package/Case:
- 20-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- 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:
- 190 MHz
- Max Propagation Delay @ V, Max CL:
- 8.5ns @ 5V, 50pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 24mA, 24mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Current - Quiescent (Iq):
- 4 µA
- Input Capacitance:
- 4 pF
- Operating Temperature:
- -55°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-TSSOP
74ACT273TTR FAQ
1.How can I place an order for 74ACT273TTR through Aetrix?
Please submit a Request for Quotation (RFQ) for 74ACT273TTR 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 74ACT273TTR reliable?
The price and inventory of 74ACT273TTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74ACT273TTR is usually 5 days.
3.What payment methods are accepted for 74ACT273TTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74ACT273TTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74ACT273TTR?
74ACT273TTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74ACT273TTR 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 74ACT273TTR?
For technical support, including 74ACT273TTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74ACT273TTR requirements.
6.How does Aetrix verify that 74ACT273TTR is sourced from the original manufacturer or authorized distributors?
All 74ACT273TTR 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 74ACT273TTR meets industry standards.
7.What is the process for return or replacement of 74ACT273TTR?
All 74ACT273TTR units undergo pre-shipment inspection (PSI). If there is an issue with 74ACT273TTR, 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 74ACT273TTR part is unused and in its original packaging.
Return procedure for 74ACT273TTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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