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STMicroelectronics 74AC374TTR
- Part No.:
- 74AC374TTR
- Manufacturer:
- STMicroelectronics
- Category:
- Flip Flops
- Package:
- 20-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
74AC374TTR.pdf
- Description:
- IC FF D-TYPE SNGL 8BIT 20TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:764
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Product details
Overview
74AC374TTR from STMicroelectronics is an octal D-type flip-flop with 3-state non-inverting outputs, clocked on the low-to-high edge, operating from 2V to 6V supply. It delivers tPLH/tPHL ≈ 5.0 ns (typ. at 5V), IOH/IOL ≥ 24 mA, and fMAX = 270 MHz (typ.), enabling high-speed data latching in bus interface and memory address registration applications.
For engineers reviewing the 74AC374TTR datasheet, 74AC374TTR pinout, 74AC374TTR application, or 74AC374TTR equivalent, key selection criteria include 3-state output enable timing (tPZL/tPLZ ≤ 12.5 ns), symmetrical drive strength, 50Ω transmission line compatibility, and latch-up immunity for industrial control backplanes.
Technical Context
The 74AC374TTR implements eight independent D-type latches synchronized to a single positive-edge-triggered clock (CK) and controlled by an active-low 3-state output enable (OE). Internal operation continues regardless of OE state-data can be captured or retained while outputs are tri-stated.
It uses sub-micron C2MOS technology with double-layer metal wiring, delivering balanced propagation delays (tPLH ≅ tPHL), 28% VCC noise immunity (VNIH/VNIL), and 2 kV HBM ESD protection on all I/O pins. Input rise/fall time is specified at 8 ns/V for VCC = 3.0/4.5/5.5 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2 V to 6 V - supports mixed-voltage system interfacing (e.g., 3.3 V logic driving 5 V bus) |
| Max Clock Frequency | 270 MHz (typ. at VCC = 5 V) - enables high-throughput data capture in fast parallel interfaces |
| Output Drive Strength | ±24 mA (min.) - drives 50 Ω transmission lines directly without external termination resistors |
| Propagation Delay | 5.0 ns (tPLH/tPHL typ. at VCC = 5 V, CL = 50 pF) - ensures tight timing margins in synchronous bus designs |
| 3-State Enable/Disable Time | tPZL ≤ 12.0 ns, tPLZ ≤ 12.5 ns (typ. at VCC = 5 V) - minimizes bus turnaround latency in bidirectional data transfer |
| Input Noise Immunity | VNIH/VNIL = 28 % VCC (min.) - rejects common-mode noise in electrically noisy industrial environments |
| Quiescent Current | ICC = 4 µA (max. at TA = 25°C) - enables low-static-power operation in standby or battery-backed systems |
Pinout & Package
TSSOP-20 package: 6.5 mm × 4.4 mm body, 0.65 mm pitch, 1.1 mm height, lead-free and RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | OE | Active-low 3-state output enable - disables all Q outputs to high-impedance without affecting internal latch state |
| 2,5,6,9,12,15,16,19 | Q0–Q7 | Non-inverting 3-state outputs - provide buffered, direction-controlled data latched on CK rising edge |
| 3,4,7,8,13,14,17,18 | D0–D7 | Data inputs - sample values on CK rising edge; unaffected by OE assertion |
| 11 | CK | Clock input - positive-edge-triggered; controls synchronous capture of Dn into Qn |
| 10 | GND | Ground reference - return path for all I/O and supply currents; must be low-inductance |
| 20 | VCC | Positive supply - powers internal logic and output drivers; requires local 100 nF decoupling |
Key Features
| Feature | Design Value |
|---|---|
| Edge-triggered latching | Low-to-high clock transition captures D-inputs synchronously - eliminates metastability risk in multi-bit bus sampling |
| Independent output control | OE pin disables outputs without halting internal clocking - allows dynamic bus arbitration while preserving latch contents |
| 50 Ω line driving | Guaranteed ±24 mA drive into 50 Ω loads - eliminates need for external series termination in high-speed PCB traces |
| High noise immunity | 28 % VCC input threshold margin - sustains reliable operation in presence of power rail ripple or crosstalk up to ±1.4 V (at 5 V) |
| Latch-up immunity | Enhanced C2MOS process - prevents destructive latch-up under transient overvoltage or ESD events per JEDEC JESD78 |
Applications
| Industrial PLC Backplane Interface | Memory Address Latching |
|---|---|
Use Scenario: Isolating and latching 8-bit address/data signals between microcontroller and peripheral modules across noisy factory-floor backplanes. IC Role / Device Role / Timing Role: Synchronous data register with 3-state outputs for bidirectional bus sharing and noise-resilient signal conditioning. Use Value: 28 % VCC noise margin and 2 kV ESD rating ensure robust operation in 24 V DC industrial environments with frequent switching transients. |
Use Scenario: Capturing and holding memory address bits during CPU read/write cycles where address stability must persist beyond clock edge. IC Role / Device Role / Timing Role: Edge-triggered address latch that freezes D-inputs on CK rising edge and holds until next cycle. Use Value: 5.0 ns typical propagation delay and balanced tPLH/tPHL minimize address setup/hold violations in 100+ MHz bus systems. |
| Test Equipment Digital Pattern Generator | Legacy Bus Buffering (ISA/PCI-X) |
Use Scenario: Generating precise, glitch-free digital stimulus waveforms with deterministic timing alignment across 8 parallel channels. IC Role / Device Role / Timing Role: Synchronized waveform register with simultaneous output update on clock edge and fast 3-state disable for pattern sequencing. Use Value: tPZL ≤ 12.0 ns and tPLZ ≤ 12.5 ns enable sub-15 ns bus turnaround - critical for high-repetition test vector execution. |
Use Scenario: Interfacing modern low-voltage controllers to legacy 5 V parallel buses requiring level translation and drive strength restoration. IC Role / Device Role / Timing Role: Level-tolerant bus driver/latch supporting 2–6 V VCC and delivering 24 mA into 50 Ω loads. Use Value: 2 V minimum supply allows direct connection to 2.5 V or 3.3 V logic while maintaining full 5 V bus drive capability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal D-type flip-flop with 3-state output applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74AC374PWR | Same AC logic family, identical pinout, but TI version has slightly higher ICC (10 µA max vs. 4 µA) and lower fMAX (220 MHz typ. at 5 V) | Valid for drop-in replacement where quiescent current < 5 µA is not required and 220 MHz clock suffices | Select when sourcing from TI-authorized channels; verify thermal derating above 85°C due to higher static power |
| 74VHC374FT | Higher VCC range (2–5.5 V), lower drive (±8 mA), slower tPLH (7.5 ns typ.), but superior 1 µA ICC (max) | Better suited for ultra-low-power portable instrumentation where speed < 100 MHz is acceptable | Prefer for battery-powered systems needing < 2 µA standby current; avoid in 50 Ω line-driving roles |
Compared with SN74AC374PWR and 74VHC374FT, the 74AC374TTR uniquely balances 270 MHz speed, 24 mA drive, and 4 µA quiescent current in TSSOP-20 - making it optimal for space-constrained, high-speed industrial bus interfaces requiring both performance and efficiency.
Availability
74AC374TTR is available at Aetrix Electronics and suitable for industrial PLC backplanes, memory address latching circuits, and test equipment digital pattern generators requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for 74AC374TTR 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, Switzerland, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.
The 74AC logic family targets high-speed, low-power digital interface applications - specifically engineered for robustness in industrial control, instrumentation, and legacy bus bridging where noise immunity and timing precision are critical.
FAQ
What is the maximum clock frequency supported by the 74AC374TTR?
The 74AC374TTR achieves a typical maximum clock frequency of 270 MHz at VCC = 5 V and TA = 25°C, with a guaranteed minimum of 100 MHz across the full industrial temperature range (–40°C to +125°C), as confirmed in AC Electrical Characteristics Table (page 5).
Can the 74AC374TTR operate reliably at 3.3 V supply?
Yes - the device is fully specified from VCC = 2 V to 6 V. At 3.3 V, it delivers fMAX = 250 MHz (typ.), tPLH/tPHL = 6.5 ns (typ.), and maintains VIH = 2.1 V (min.) and VIL = 1.5 V (max.), ensuring clean logic thresholds and noise margin in 3.3 V systems.
Does OE assertion affect internal latch state or clock functionality?
No - asserting OE (high) places Q0–Q7 in high-impedance but does not interrupt internal clocking or data retention. D-inputs remain sampled on each CK rising edge, and previously latched data persists; this enables seamless bus arbitration without losing register state.
Is the 74AC374TTR pin-compatible with standard 74LS374 or 74HC374 devices?
Yes - it is functionally and pin-compatible with 74-series 374 devices, including 74LS374 and 74HC374, sharing identical pin assignments (OE, CK, D0–D7, Q0–Q7, VCC, GND) and truth table behavior, though AC/DC parameters differ significantly per logic family.
74AC374TTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- 74AC
- Package/Case:
- 20-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Function:
- Standard
- Type:
- D-Type
- Output Type:
- Tri-State, Non-Inverted
- Number of Elements:
- 1
- Number of Bits per Element:
- 8
- Clock Frequency:
- 270 MHz
- Max Propagation Delay @ V, Max CL:
- 9.5ns @ 5V, 50pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 24mA, 24mA
- Voltage - Supply:
- 2V ~ 6V
- 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
74AC374TTR FAQ
1.How can I place an order for 74AC374TTR through Aetrix?
Please submit a Request for Quotation (RFQ) for 74AC374TTR 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 74AC374TTR reliable?
The price and inventory of 74AC374TTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74AC374TTR is usually 5 days.
3.What payment methods are accepted for 74AC374TTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74AC374TTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74AC374TTR?
74AC374TTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74AC374TTR 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 74AC374TTR?
For technical support, including 74AC374TTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74AC374TTR requirements.
6.How does Aetrix verify that 74AC374TTR is sourced from the original manufacturer or authorized distributors?
All 74AC374TTR 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 74AC374TTR meets industry standards.
7.What is the process for return or replacement of 74AC374TTR?
All 74AC374TTR units undergo pre-shipment inspection (PSI). If there is an issue with 74AC374TTR, 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 74AC374TTR part is unused and in its original packaging.
Return procedure for 74AC374TTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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