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STMicroelectronics 74ACT299MTR
- Part No.:
- 74ACT299MTR
- Manufacturer:
- STMicroelectronics
- Category:
- Shift Registers
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
74ACT299MTR.pdf
- Description:
- IC SHIFT REG 8-BIT PIPO 20-SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,538
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Product details
Overview
74ACT299MTR from STMicroelectronics is an advanced high-speed CMOS 8-bit parallel-in/parallel-out (PIPO) shift register with asynchronous clear, 3-state outputs, and TTL-compatible inputs. It operates from 4.5V to 5.5V, delivers symmetrical 24mA output drive, supports 240MHz max clock frequency (typ.), and features pin- and function-compatibility with standard 74-series 299 devices for drop-in replacement in legacy bus-interface and data-routing applications.
For engineers reviewing the 74ACT299MTR datasheet, 74ACT299MTR pinout, 74ACT299MTR application, or 74ACT299MTR equivalent, key selection criteria include its asynchronous clear timing (tPHL ≤ 18.0 ns), balanced propagation delays (tPLH ≅ tPHL), 50Ω transmission line driving capability, and dual serial shift directions (left/right) with independent enable-controlled 3-state I/Os.
Technical Context
The 74ACT299 implements a synchronous edge-triggered (LOW-to-HIGH clock) 8-bit register with four functional modes-HOLD, SHIFT LEFT, SHIFT RIGHT, and LOAD DATA-selected via S0/S1 inputs. Its asynchronous CLEAR input resets all flip-flops independently of clock timing, enabling immediate state reset without cycle delay.
All eight parallel I/O terminals (A/QA–H/QH) support bidirectional 3-state operation controlled by active-low G1/G2 enables, while dedicated serial outputs QA′–QH′ provide non-inverted shifted data. Input thresholds (VIH ≥ 2.0V, VIL ≤ 0.8V) and ESD protection (2kV HBM) ensure robust interfacing with TTL, NMOS, and CMOS logic families.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 4.5V to 5.5V - Ensures stable operation across industrial-grade 5V supply tolerances. |
| fMAX (Typ.) | 240MHz - Enables high-throughput data routing in fast control and test systems. |
| IOL / IOH (Min.) | 24mA - Drives 50Ω transmission lines directly without external buffers. |
| tPLH / tPHL (Max.) | 16.0ns - Guarantees predictable, balanced timing for synchronous data capture. |
| ICC (Max.) | 160µA at TA = –55°C to +125°C - Supports low-static-power operation in extended-temperature environments. |
| VIH / VIL | 2.0V (min) / 0.8V (max) - Ensures reliable logic-level recognition from TTL and older CMOS sources. |
| CLEAR Pulse Width | 5.0ns (min) - Allows short, noise-immune reset pulses in high-speed sequencers. |
Pinout & Package
74ACT299MTR is supplied in a 20-pin SOIC (SO-20) package per mechanical drawing P013L, with 1.27mm pitch, body width 7.4–7.6mm, and lead length 0.50–1.27mm.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | S0, S1 | Mode select inputs determining HOLD/SHIFT LEFT/SHIFT RIGHT/LOAD function. |
| 2, 3 | G1, G2 | Active-low 3-state output enables; either high forces A/QA–H/QH into high-Z. |
| 4–7, 13–16 | A/QA–H/QH | Bidirectional parallel I/O pins supporting data load, hold, or output under 3-state control. |
| 8, 17 | QA′–QH′ | Dedicated serial outputs reflecting current register contents post-shift (non-inverted). |
| 9 | CLEAR | Asynchronous active-low master reset; overrides clock and mode logic to zero all bits. |
| 11 | SR | Serial data input for right-shift operations; sampled on rising clock edge. |
| 12 | CLOCK | Edge-triggered (LOW-to-HIGH) control signal synchronizing all register updates. |
| 18 | SL | Serial data input for left-shift operations; sampled on rising clock edge. |
| 10 | GND | Reference ground terminal for power and signal integrity. |
| 20 | VCC | Positive supply rail (4.5–5.5V); powers internal logic and output drivers. |
Key Features
| Feature | Design Value |
|---|---|
| Asynchronous CLEAR | Resets all 8 bits within 18.0ns (max) regardless of clock phase or mode state. |
| 3-State Parallel I/O | Eight bidirectional pins (A/QA–H/QH) with independent G1/G2 control for bus sharing. |
| Dual Serial Shift Direction | Independent SR and SL inputs enable flexible data reordering without external logic. |
| TTL-Compatible Inputs | VIH ≥ 2.0V and VIL ≤ 0.8V allow direct interface with legacy 5V TTL systems. |
| 50Ω Line Driving | 24mA output drive ensures clean signal integrity on controlled-impedance PCB traces. |
Applications
| Industrial Bus Interface | Test Equipment Data Routing |
|---|---|
|
Use Scenario: Isolating and multiplexing data between multiple microcontroller peripherals on a shared 8-bit data bus. IC Role / Device Role / Timing Role: Bidirectional PIPO register acting as a programmable bus buffer with 3-state control and asynchronous reset. Use Value: Eliminates need for discrete transceivers by providing TTL-compatible, high-drive I/O with precise timing control (tPLH/tPHL ≤ 16ns). |
Use Scenario: Capturing and shifting test vectors in automated boundary-scan or functional test fixtures. IC Role / Device Role / Timing Role: Synchronous data capture and serial retransmission node synchronized to system clock edges. Use Value: Enables deterministic vector loading via parallel load and compact serial output (QA′–QH′) at up to 240MHz clock rate. |
| Legacy System Emulation | Digital Signal Path Control |
|
Use Scenario: Replacing obsolete 74LS299 in retro-computing or instrumentation upgrades requiring pin compatibility. IC Role / Device Role / Timing Role: Drop-in functional replacement preserving original board layout and timing behavior. Use Value: Maintains identical S0/S1/G1/G2/CLEAR pin mapping and truth table while improving speed (240MHz vs. ~30MHz) and drive strength. |
Use Scenario: Dynamically configuring signal paths in FPGA companion logic or digital audio routing matrices. IC Role / Device Role / Timing Role: Configurable shift/load register managing channel enable/disable states across parallel buses. Use Value: Asynchronous CLEAR allows instantaneous path reset during fault recovery, independent of system clock domain. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8-bit PIPO shift register applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74ACT299N | DIP-20 package; higher thermal resistance; no moisture sensitivity level rating. | Suitable for prototyping or through-hole assembly; not recommended for high-density surface-mount production. | Select when manual soldering or breadboard validation is required. |
| 74ACT299TTR | TSSOP-20 package; 4.4mm width; 0.65mm pitch; rated for MSL3 moisture sensitivity. | Better suited for space-constrained PCBs and automated reflow processes with tighter placement tolerances. | Select when board area is constrained and IPC-compliant reflow is used. |
Compared with SN74ACT299N and 74ACT299TTR, the 74ACT299MTR offers SOIC-20 packaging optimized for hand-soldering accessibility and moderate-density SMT assembly, balancing thermal performance, manufacturability, and legacy footprint compatibility.
Availability
74ACT299MTR is available at Aetrix Electronics and suitable for industrial bus interface, test equipment data routing, and legacy system emulation requiring stable component supply and long-term obsolescence management.
Supply support for 74ACT299MTR 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, specializing in automotive, industrial, and power management ICs with broad analog, digital, and mixed-signal portfolios.
The 74ACT299 belongs to ST's Advanced CMOS (ACT) logic family, designed specifically for high-speed, low-power 5V digital systems requiring TTL interoperability and robust noise immunity in harsh industrial environments.
FAQ
What is the minimum pulse width required for the CLEAR input?
The 74ACT299MTR requires a minimum CLEAR low pulse width of 5.0ns across all operating temperatures (–55°C to +125°C) to guarantee reliable asynchronous reset of all eight register bits, as verified in AC electrical characteristics tables under tW(CLEAR).
Can the 74ACT299MTR drive a 50Ω transmission line directly?
Yes - the device guarantees |IOH| = IOL = 24mA (min) at VCC = 4.5V to 5.5V, enabling direct 50Ω line driving without external buffers, as confirmed in DC specifications and explicitly stated in the product description.
Is the 74ACT299MTR pin-compatible with older 74LS299 devices?
Yes - the 74ACT299MTR is explicitly designed for pin and function compatibility with the 74-series 299 family, including 74LS299, preserving identical pin numbering, truth table behavior, and mode-select logic per the manufacturer's datasheet description.
What is the maximum clock frequency supported over the full temperature range?
The guaranteed maximum clock frequency is 80MHz across –40°C to +85°C and –55°C to +125°C ranges; the 240MHz value is a typical (not guaranteed) specification measured only at TA = 25°C per AC electrical characteristics.
74ACT299MTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- 74ACT
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Logic Type:
- Shift Register
- Output Type:
- Tri-State
- Number of Elements:
- 1
- Number of Bits per Element:
- 8
- Function:
- Universal
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SO
74ACT299MTR FAQ
1.How can I place an order for 74ACT299MTR through Aetrix?
Please submit a Request for Quotation (RFQ) for 74ACT299MTR 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 74ACT299MTR reliable?
The price and inventory of 74ACT299MTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74ACT299MTR is usually 5 days.
3.What payment methods are accepted for 74ACT299MTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74ACT299MTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74ACT299MTR?
74ACT299MTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74ACT299MTR 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 74ACT299MTR?
For technical support, including 74ACT299MTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74ACT299MTR requirements.
6.How does Aetrix verify that 74ACT299MTR is sourced from the original manufacturer or authorized distributors?
All 74ACT299MTR 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 74ACT299MTR meets industry standards.
7.What is the process for return or replacement of 74ACT299MTR?
All 74ACT299MTR units undergo pre-shipment inspection (PSI). If there is an issue with 74ACT299MTR, 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 74ACT299MTR part is unused and in its original packaging.
Return procedure for 74ACT299MTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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