My Inquiry
My Account
onsemi 74VHCT540AN
- Part No.:
- 74VHCT540AN
- Manufacturer:
- onsemi
- Package:
- 20-DIP (0.300", 7.62mm)
- Datasheet:
-
74VHCT540AN.pdf
- Description:
- IC BUFFER INVERT 5.5V 20DIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,677
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
74VHCT540AN from Fairchild Semiconductor is an octal non-inverting buffer/line driver with 3-STATE outputs, designed for memory and address bus driving, clock distribution, and bidirectional bus interfacing in 5V TTL-compatible systems. It operates at VCC = 4.5–5.5V, delivers tPD = 5.4ns (typ), supports ±25mA output drive, and features flow-through pinout for microprocessor output port applications.
For engineers reviewing the 74VHCT540AN datasheet, pinout, applications, or equivalent options, key selection considerations include 3-STATE timing (tPZL/tPLZ ≤ 14ns), input/output voltage tolerance up to 7V, low ICC = 4µA (max), and compatibility with 74HCT540 logic families in mixed-voltage interface designs.
Technical Context
The 74VHCT540AN implements dual 3-STATE enable inputs (OE1, OE2) controlling eight independent non-inverting buffers. All inputs and outputs feature overvoltage protection allowing 0V–7V signal levels regardless of VCC, enabling safe interfacing between 3V and 5V domains or battery-backed dual-supply systems.
Its silicon gate CMOS process achieves bipolar-Schottky TTL speed with CMOS power efficiency. The flow-through architecture places inputs (I0–I7) on one side and outputs (O0–O7) on the opposite side - a layout advantage for PCB density and microprocessor I/O port routing without signal layer crossover.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5V to 5.5V - ensures stable operation across industrial 5V rail tolerances. |
| Propagation Delay | 5.4ns (typ) at CL = 15pF - enables high-speed address/data buffering in 20+ MHz bus systems. |
| Output Drive | ±25mA per output - sufficient to drive 50Ω transmission lines or multiple TTL loads. |
| Quiescent Current | 4µA (max) at TA = 25°C - supports low-power standby modes in battery-aware systems. |
| Input/Output Voltage Range | –0.5V to +7.0V - allows hot-swap and level-shifting without external clamping diodes. |
| 3-STATE Enable Time | 8.3ns (typ) at CL = 15pF - minimizes bus contention window during direction switching. |
| Operating Temperature | –40°C to +85°C - qualified for industrial ambient environments without derating. |
Pinout & Package
74VHCT540AN is supplied in a 20-lead Small Outline Integrated Circuit (SOIC) package, JEDEC MS-013 compliant, 0.300" wide (Package Number M20B). Body dimensions: 12.8mm × 7.5mm × 2.35mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | OE1, OE2 | Dual active-low 3-STATE enable inputs - both must be LOW to activate all eight outputs. |
| 2–9 | I0–I7 | Non-inverting data inputs - placed on left side for flow-through board layout. |
| 11–18 | O0–O7 | 3-STATE buffered outputs - placed on right side, aligned opposite inputs for minimal trace length. |
| 10 | GND | Ground reference - decoupling capacitor placement adjacent to this pin reduces noise coupling. |
| 20 | VCC | +5V supply - requires local 0.1µF ceramic bypass capacitor near pin 20. |
Key Features
| Feature | Design Value |
|---|---|
| Flow-through pinout | Inputs (pins 2–9) and outputs (pins 11–18) on opposite sides - simplifies microprocessor port routing and increases PCB trace density. |
| Overvoltage-tolerant I/O | Supports –0.5V to +7.0V on all pins regardless of VCC - eliminates need for external level shifters in 3V/5V mixed-signal interfaces. |
| Low ICC quiescent current | 4µA maximum at 25°C - enables use in always-on subsystems without compromising system-level power budget. |
| Pin/function compatibility | Direct replacement for 74HCT540 - allows drop-in upgrade path with identical logic behavior and timing envelope. |
| Power-down protection | Input and output protection circuits remain active even when VCC = 0V - prevents latch-up during hot-insertion or partial power sequencing. |
Applications
| Memory Address Buffering | Microprocessor I/O Port Expansion |
|---|---|
|
Use Scenario: Driving 16-bit address bus from an 8-bit microcontroller with external RAM/ROM. IC Role / Device Role / Timing Role: Non-inverting octal buffer providing fanout and noise immunity while maintaining setup/hold timing margins. Use Value: Flow-through pinout reduces trace skew; 5.4ns tPD ensures address stability before memory access window closes. |
Use Scenario: Expanding GPIO count of an 8051 or Z80-based controller for peripheral control. IC Role / Device Role / Timing Role: Bidirectional bus transceiver (with external direction control) acting as programmable output port. Use Value: Dual OE inputs allow synchronized enable/disable of all outputs; ±25mA drive supports LED arrays or relay drivers directly. |
| 5V Bus Interface Isolation | Legacy System Clock Distribution |
|
Use Scenario: Interfacing a 3.3V FPGA I/O bank to a legacy 5V ISA bus without level translators. IC Role / Device Role / Timing Role: Voltage-tolerant buffer isolating domains while preserving signal integrity and timing alignment. Use Value: 0V–7V I/O rating permits direct connection; no external components needed for safe 3.3V-to-5V translation. |
Use Scenario: Distributing a 25MHz system clock to multiple 74-series logic devices on a backplane. IC Role / Device Role / Timing Role: Low-skew clock driver with matched propagation delay across all eight outputs. Use Value: Output-to-output skew ≤1.0ns (CL = 50pF) maintains clock phase alignment across fanout branches. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal buffer/line driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 74HCT540N | Identical pinout and logic function; slightly higher tPD (6.0ns typ) and ICC (8µA max). | Same 5V TTL-compatible use cases; less suitable for ultra-low-power standby modes. | Select when legacy HCT family sourcing is preferred and 0.6ns timing margin is acceptable. |
| SN74LVTH540PW | 3.3V-only supply (2.7–3.6V); LVTH logic family; lower VIL/VIH thresholds; 3.5ns tPD. | Designed for 3.3V systems only; not overvoltage tolerant beyond 3.6V. | Choose for new 3.3V designs requiring faster timing and lower supply voltage - not interoperable with 5V buses. |
Compared with 74HCT540N and SN74LVTH540PW, the 74VHCT540AN uniquely combines 5V operation, 7V I/O tolerance, sub-6ns speed, and <5µA quiescent current - making it optimal for industrial 5V systems requiring robust mixed-voltage interfacing and low-power idle states.
Availability
74VHCT540AN is available at Aetrix Electronics and suitable for memory address buffering, microprocessor I/O expansion, 5V bus interface isolation, and legacy system clock distribution requiring stable component supply and long-term industrial availability.
Supply support for 74VHCT540AN 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
Fairchild Semiconductor was a U.S.-based semiconductor company specializing in analog and mixed-signal ICs, power management, and logic devices before its acquisition by ON Semiconductor in 2016.
The 74VHCT540AN belongs to Fairchild's VHCT (Very High-Speed CMOS TTL-compatible) logic family, engineered to replace bipolar TTL in high-speed, low-power 5V digital systems while maintaining pin and functional compatibility.
FAQ
What is the maximum operating temperature range for the 74VHCT540AN?
The 74VHCT540AN is rated for operation from –40°C to +85°C under recommended conditions. This industrial temperature range ensures reliable performance in embedded controllers, industrial PLCs, and automotive body electronics where ambient thermal stress is present. All AC and DC specifications in the datasheet are guaranteed across this full range, with no derating required.
Does the 74VHCT540AN support 3.3V input signals when powered at 5V?
Yes - the 74VHCT540AN accepts 3.3V logic-level inputs while operating at VCC = 5V. Its VIH threshold is guaranteed at 2.0V min (over 4.5–5.5V VCC), and input voltage tolerance extends to –0.5V to +7.0V. This allows direct interfacing with 3.3V microcontrollers or FPGAs without level-shifting circuitry, provided input current limits are observed.
Can the 74VHCT540AN be used with VCC = 0V for hot-swap applications?
Yes - the 74VHCT540AN includes power-down protection that remains active even when VCC = 0V. Inputs and outputs tolerate –0.5V to +7.0V under this condition, preventing damage during live insertion or partial power sequencing. This makes the 74VHCT540AN suitable for hot-pluggable modules and modular backplane systems.
How does the flow-through pinout of the 74VHCT540AN improve PCB layout?
The 74VHCT540AN places inputs (I0–I7) on pins 2–9 (left side) and outputs (O0–O7) on pins 11–18 (right side), enabling straight-through signal routing. This eliminates layer jumps and reduces trace length mismatch in microprocessor port expansions - improving signal integrity, easing autorouting, and increasing board density compared to traditional in-line pinouts like those in 74LS540.
What is the output leakage current specification for the 74VHCT540AN in 3-STATE mode?
In 3-STATE (high-impedance) mode, the 74VHCT540AN specifies IOZ = ±0.25µA (typ) and ±2.5µA (max) at VCC = 5.5V, with inputs at VIH or VIL and outputs pulled to VCC or GND. This ultra-low off-state current prevents unintended loading of shared buses and supports clean bus arbitration in multi-driver systems using the 74VHCT540AN.
74VHCT540AN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74VHCT
- Package/Case:
- 20-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Logic Type:
- Buffer, Inverting
- Number of Elements:
- 1
- Number of Bits per Element:
- 8
- Input Type:
- -
- Output Type:
- 3-State
- Current - Output High, Low:
- 8mA, 8mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 20-PDIP
74VHCT540AN FAQ
1.How can I place an order for 74VHCT540AN through Aetrix?
Please submit a Request for Quotation (RFQ) for 74VHCT540AN 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 74VHCT540AN reliable?
The price and inventory of 74VHCT540AN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74VHCT540AN is usually 5 days.
3.What payment methods are accepted for 74VHCT540AN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74VHCT540AN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74VHCT540AN?
74VHCT540AN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74VHCT540AN 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 74VHCT540AN?
For technical support, including 74VHCT540AN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74VHCT540AN requirements.
6.How does Aetrix verify that 74VHCT540AN is sourced from the original manufacturer or authorized distributors?
All 74VHCT540AN 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 74VHCT540AN meets industry standards.
7.What is the process for return or replacement of 74VHCT540AN?
All 74VHCT540AN units undergo pre-shipment inspection (PSI). If there is an issue with 74VHCT540AN, 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 74VHCT540AN part is unused and in its original packaging.
Return procedure for 74VHCT540AN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
74VHCT540AN Tags
-
SN74LVC1G17DBVR
Texas Instruments
-
SN74LVC1G07DCKR
Texas Instruments
-
SN74LVC1G17DCKR
Texas Instruments
-
SN74LVC1G07DBVR
Texas Instruments
-
SN74LVC1G125DCKR
Texas Instruments
-
SN74AHCT1G126DBVR
Texas Instruments
-
SN74LVC1G125DBVR
Texas Instruments
-
SN74AHCT1G125DBVR
Texas Instruments
-
SN74LVC2G17DBVR
Texas Instruments
-
SN74LVC2G07DCKR
Texas Instruments
-
SN74LVC1G34DCKR
Texas Instruments
-
SN74LVC2G17DCKR
Texas Instruments
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
