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STMicroelectronics 74VHCT373ATTR
- Part No.:
- 74VHCT373ATTR
- Manufacturer:
- STMicroelectronics
- Category:
- Latches
- Package:
- 20-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
74VHCT373ATTR.pdf
- Description:
- IC D-TYPE TRANSP SGL 8:8 20TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,122
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Product details
Overview
74VHCT373ATTR from STMicroelectronics is an octal non-inverting D-type transparent latch with 3-state outputs, designed for bus-oriented applications requiring bidirectional data flow control and output isolation. It features 6.4 ns typical propagation delay (D to Q), ±8 mA output drive, TTL-compatible inputs (VIH ≥ 2 V, VIL ≤ 0.8 V), and operates from 4.5 V to 5.5 V. Used in microprocessor address/data latching and memory interfacing.
For engineers reviewing the 74VHCT373ATTR datasheet, 74VHCT373ATTR pinout, 74VHCT373ATTR application, or 74VHCT373ATTR equivalent, key selection criteria include latch enable timing (ts = 1.5 ns, th = 3.5 ns), 3-state output disable time (tPHZ = 12.0 ns max), power-down input/output protection, and TSSOP-20 package compatibility with 5 V system buses.
Technical Context
This device implements a dual-control transparent latch architecture: data passes through when LE is high, and freezes on the falling edge of LE. Output state is independently managed by active-low OE, enabling high-impedance tri-state operation without affecting latch state.
All inputs tolerate 0–7 V regardless of VCC, supporting mixed-voltage interfacing (e.g., 5 V logic driving 3 V systems). Input thresholds follow TTL levels, and outputs exhibit symmetrical drive strength (|IOH| = IOL ≥ 8 mA) with low dynamic noise (VOLP ≤ 0.9 V).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Propagation Delay (D→Q) | 6.4 ns typ. at VCC = 5 V, CL = 15 pF - ensures tight timing alignment in high-speed address/data capture |
| Output Drive Strength | ±8 mA min. - supports direct connection to standard 5 V TTL/CMOS loads without buffering | Supply Voltage Range | 4.5 V to 5.5 V - compatible with regulated 5 V rails and tolerant of ±10 % variation |
| Input Thresholds | VIH ≥ 2.0 V, VIL ≤ 0.8 V - guarantees interoperability with legacy TTL outputs |
| Quiescent Current | 4 µA max. at TA = 25°C - enables low-static-power operation in standby or idle bus states |
| ESD Immunity | 2 kV HBM - protects against handling-induced discharge during PCB assembly and test |
Pinout & Package
TSSOP-20 package: 6.5 mm × 4.4 mm body, 0.65 mm pitch, 1.2 mm height, lead-free and RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | OE | Active-low 3-state output enable - controls all eight Q outputs simultaneously |
| 2,5,6,9,12,15,16,19 | Q0–Q7 | Non-inverting latched outputs - reflect D-input state when OE = L and LE has latched |
| 3,4,7,8,13,14,17,18 | D0–D7 | Data inputs - sampled transparently while LE = H; latched on LE falling edge |
| 11 | LE | Latch enable - high enables transparency; low captures and holds D-input level |
| 10 | GND | Ground reference - common return for all signals and supply current |
| 20 | VCC | Positive supply - powers internal logic and output drivers; must be decoupled locally |
Key Features
| Feature | Design Value |
|---|---|
| Power-down protection | Inputs and outputs accept 0–7 V independent of VCC - prevents back-driving and latch-up during power sequencing |
| Balanced propagation delays | tPLH ≅ tPHL - minimizes skew between rising/falling output transitions for clean bus timing |
| Low dynamic noise | VOLP ≤ 0.9 V - reduces ground bounce and crosstalk in dense 5 V digital layouts |
| Improved latch-up immunity | Qualified per JEDEC JESD78 - withstands transient overvoltage without destructive latch-up |
Applications
| Microprocessor Address Latching | Memory Data Bus Isolation |
|---|---|
Use Scenario: Holding address bits stable during multiplexed AD bus cycles in 8051 or Z80-based systems. IC Role / Device Role / Timing Role: Transparent latch capturing address on LE falling edge; OE used for bus release during data phase. Use Value: Enables single-cycle address setup with 6.4 ns D→Q delay and 3.5 ns hold time margin. | Use Scenario: Isolating SRAM or EPROM data lines from CPU during DMA or peripheral access. IC Role / Device Role / Timing Role: 3-state output buffer controlled by OE; latches data only when required for write-back or read-through. Use Value: Prevents bus contention with ±8 mA drive and 12.0 ns max output disable time. |
| Industrial I/O Expansion | Legacy Peripheral Interface |
Use Scenario: Buffering parallel GPIO signals from PLC controllers to external sensors/actuators. IC Role / Device Role / Timing Role: Level-shifting latch with TTL-compatible inputs accepting 2 V VIH, enabling direct connection to 3.3 V MCU outputs via pull-up. Use Value: Eliminates external level translators while maintaining 2 kV ESD robustness for factory-floor environments. | Use Scenario: Interfacing ISA-bus peripherals (e.g., DACs, ADCs) to modern embedded hosts via bridge logic. IC Role / Device Role / Timing Role: Bus transceiver replacement - latches control/status bits and gates data using OE/LE coordination. Use Value: Matches 74LS373 timing margins (ts/th) and pinout, allowing drop-in replacement without layout change. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal latch with 3-state output applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HCT373PW | Same logic function, SOIC-20 package; tPD = 17 ns (max) vs. 13.5 ns (max) for VHCT; ICC = 4 µA (same) | SOIC footprint requires PCB redesign; slightly slower but wider temp range (–40°C to +85°C vs. –55°C to +125°C) | Select for cost-sensitive industrial designs where TSSOP assembly is unavailable |
| 74LCX373MTCX | Lower VCC range (2.0–3.6 V); incompatible with 5 V systems; tPD = 5.2 ns (typ) at 3.3 V | Not suitable for 5 V bus interfaces; intended for 3.3 V mixed-signal subsystems only | Choose only when migrating to 3.3 V logic domains with strict speed requirements |
Compared with SN74HCT373PW and 74LCX373MTCX, the 74VHCT373ATTR delivers superior 5 V timing performance (6.4 ns typ.), extended temperature support (–55°C to +125°C), and TSSOP-20 space savings-making it optimal for compact, high-reliability 5 V embedded control and instrumentation.
Availability
74VHCT373ATTR is available at Aetrix Electronics and suitable for microprocessor address latching, memory data bus isolation, and industrial I/O expansion requiring stable component supply across automotive-grade temperature ranges and long-lifecycle programs.
Supply support for 74VHCT373ATTR 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 analog, MCU, power, and discrete technologies for industrial, automotive, and consumer markets.
The VHCT logic family targets high-speed, low-power 5 V CMOS applications with TTL compatibility and enhanced robustness-designed specifically for reliable bus interface and data capture in harsh or thermally demanding environments.
FAQ
Can 74VHCT373ATTR operate with a 3.3 V supply?
No. The device is specified only for 4.5 V to 5.5 V operation. Applying 3.3 V violates recommended operating conditions and results in undefined logic levels, excessive propagation delay, and potential failure to meet VIH/VIL thresholds. For 3.3 V systems, consider the 74LCX373 or 74ALVC373 families instead.
What happens to outputs when VCC = 0 V but inputs are driven?
Outputs remain in high-impedance state due to built-in power-down protection. Inputs accept 0–7 V regardless of VCC, preventing back-powering and latch-up. This allows hot-plug or partial-power-down scenarios without damaging the device or disturbing other bus components.
Is the 74VHCT373ATTR pin-compatible with the 74LS373?
Yes - identical pinout and logic function (non-inverting octal latch with separate LE and OE). However, VHCT offers faster propagation (6.4 ns vs. ~25 ns), lower ICC (4 µA vs. ~25 mA), and higher noise immunity. No board change is needed, but decoupling and layout should accommodate higher edge rates.
How is output skew minimized in this device?
Output-to-output skew (tOSLH/tOSHL) is guaranteed ≤1.0 ns under worst-case conditions (VCC = 5.0 V, CL = 50 pF). This is achieved via matched internal driver geometry and symmetrical layout of Q0–Q7 paths - critical for simultaneous bus line assertion in memory or display interfaces.
74VHCT373ATTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- 74VHCT
- Package/Case:
- 20-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Logic Type:
- D-Type Transparent Latch
- Circuit:
- 8:8
- Output Type:
- Tri-State
- Voltage - Supply:
- 4.5V ~ 5.5V
- Independent Circuits:
- 1
- Delay Time - Propagation:
- 6.4ns
- Current - Output High, Low:
- 8mA, 8mA
- Operating Temperature:
- -55°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-TSSOP
74VHCT373ATTR FAQ
1.How can I place an order for 74VHCT373ATTR through Aetrix?
Please submit a Request for Quotation (RFQ) for 74VHCT373ATTR 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 74VHCT373ATTR reliable?
The price and inventory of 74VHCT373ATTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74VHCT373ATTR is usually 5 days.
3.What payment methods are accepted for 74VHCT373ATTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74VHCT373ATTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74VHCT373ATTR?
74VHCT373ATTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74VHCT373ATTR 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 74VHCT373ATTR?
For technical support, including 74VHCT373ATTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74VHCT373ATTR requirements.
6.How does Aetrix verify that 74VHCT373ATTR is sourced from the original manufacturer or authorized distributors?
All 74VHCT373ATTR 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 74VHCT373ATTR meets industry standards.
7.What is the process for return or replacement of 74VHCT373ATTR?
All 74VHCT373ATTR units undergo pre-shipment inspection (PSI). If there is an issue with 74VHCT373ATTR, 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 74VHCT373ATTR part is unused and in its original packaging.
Return procedure for 74VHCT373ATTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
74VHCT373ATTR Tags
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