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onsemi MM74HCT540WMX
- Part No.:
- MM74HCT540WMX
- Manufacturer:
- onsemi
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
MM74HCT540WMX.pdf
- Description:
- IC BUFFER INVERT 5.5V 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,046
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Product details
Overview
MM74HCT540WMX from onsemi is an octal 3-state inverting buffer IC designed for high-speed bus interface applications in TTL-CMOS mixed-signal systems. It delivers 12 ns typical propagation delay at 5 V, ±6 mA output drive per pin, and operates across −55 °C to +125 °C with TTL-compatible inputs and 3-state control via dual NOR-gated enable (G1/G2). It is used in industrial backplane data routing and legacy system bus buffering.
For engineers reviewing the MM74HCT540WMX datasheet, pinout, applications, or equivalent options, key selection criteria include its inverting logic function, SOIC-20 WB package, guaranteed 25 ns max propagation delay at 125 °C, 3-state enable timing, and compatibility with LS-TTL replacement in power-constrained designs.
Technical Context
The MM74HCT540WMX implements eight independent inverting buffer channels with a shared two-input NOR gate controlling all outputs' 3-state behavior - either G1 or G2 high forces all outputs into high-impedance. Its silicon-gate CMOS process ensures TTL-level input thresholds (VIH = 2.0 V, VIL = 0.8 V) while maintaining CMOS quiescent current efficiency.
Designed for bus-oriented architectures, it features opposite-side pinout (inputs on one side, outputs on the other) to simplify PCB trace routing and reduce crosstalk. All inputs include diode-based ESD protection to VCC and GND, and output capacitance is specified at ≤20 pF across temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Function | Inverting octal buffer with 3-state output control |
| Propagation Delay | 12 ns typical, 30 ns max at VCC = 5 V, CL = 50 pF, TA = −55 °C to +125 °C |
| Output Drive | ±6 mA min per output at VCC = 4.5 V, ensuring robust driving of 15 LS-TTL loads |
| Supply Voltage Range | 4.5 V to 5.5 V - compatible with standard 5 V TTL/CMOS rails |
| Operating Temperature | −55 °C to +125 °C - qualified for extended industrial and automotive under-hood environments |
| Quiescent Current | 160 µA max at TA = −55 °C to +125 °C - enables low-static-power system design |
| Input/Output Capacitance | CIN ≤ 10 pF, COUT ≤ 20 pF - minimizes loading on driving and driven stages |
Pinout & Package
MM74HCT540WMX is housed in a Pb-free SOIC-20 WB (Wide Body) package per case outline 751D-05, with 1.27 mm pitch, 12.8 mm × 7.5 mm body size, and 2.5 mm height. Pin numbering follows standard SOIC top-view convention with Pin 1 marked by notch or bevel.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | 3-State Enable Inputs (G1, G2) | NOR logic: either high disables all outputs (high-Z); both low enables inverting buffer action |
| 2–9 | Inputs (A1–A8) | TTL-compatible digital inputs; internally protected by clamp diodes to VCC and GND |
| 11–18 | Outputs (Y1–Y8) | Inverted buffered outputs; each capable of sourcing/sinking ≥6 mA with VOL ≤ 0.4 V at 6 mA |
| 10 | GND | Ground reference for all logic and I/O; decoupling capacitor placement critical for noise immunity |
| 20 | VCC | Positive supply (4.5–5.5 V); requires local 0.1 µF ceramic bypass near pin |
Key Features
| Feature | Design Value |
|---|---|
| TTL Input Compatibility | VIH = 2.0 V / VIL = 0.8 V thresholds allow direct connection to LS-TTL without level shifters |
| High-Speed Bus Interface | 12 ns typical tPLH/tPHL enables reliable operation on 30+ MHz system buses with 50 pF load |
| Low-Power CMOS Efficiency | 160 µA max ICC supports energy-sensitive industrial control modules and battery-backed systems |
| Robust 3-State Control | Dual-NOR enable architecture prevents partial output enable; eliminates bus contention during state transitions |
| Pb-Free SOIC-20 WB Packaging | RoHS-compliant wide-body SOIC meets IPC-7351B footprint standards and supports automated reflow |
Applications
| Industrial PLC Backplane Buffering | Legacy Computer System Bus Isolation |
|---|---|
Use Scenario: Bidirectional data routing between CPU and I/O modules in programmable logic controllers operating at −40 °C to +85 °C ambient. IC Role / Device Role / Timing Role: Inverting 3-state buffer isolating address/data lines during DMA cycles; enables clean bus turnarounds. Use Value: 25 ns max disable time (tPLZ/tPHZ) ensures sub-40 ns bus release, preventing data corruption during high-frequency polling. |
Use Scenario: Interfacing ISA-bus peripherals to modern microcontroller-based bridge logic in retro-computing hardware restoration. IC Role / Device Role / Timing Role: Level-shifting and bus-driving buffer translating TTL signals between vintage and contemporary logic families. Use Value: TTL-compatible inputs and 6 mA drive eliminate need for external pull-ups or driver stages, simplifying board redesign. |
| Automotive Engine Control Unit (ECU) Signal Conditioning | Test Equipment Digital Pattern Generator Interface |
Use Scenario: Isolating sensor signal conditioning circuitry from main ECU bus in under-hood environments up to +125 °C. IC Role / Device Role / Timing Role: Inverting buffer with 3-state control enabling selective channel activation during diagnostic mode. Use Value: −55 °C to +125 °C rating and 160 µA max ICC support long-term reliability in thermally stressed engine compartments. |
Use Scenario: Driving multiple DUT inputs simultaneously from a single pattern generator channel in ATE systems. IC Role / Device Role / Timing Role: Fanout expander providing eight synchronized, inverted outputs with matched propagation delay. Use Value: 12 ns typical tPLH/tPHL and ≤3 ns skew between outputs ensure precise timing alignment across parallel test vectors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal inverting buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HCT540N | Same logic function and pinout; rated only to +70 °C (commercial), not −55 °C to +125 °C | Suitable for office equipment or consumer electronics; insufficient for extended-temperature industrial use | Select MM74HCT540WMX when full industrial temperature range or automotive qualification is required. |
| 74VHC540M | Higher speed (7.5 ns typ), but VIH/VIL thresholds differ (VIH = 3.5 V min); not TTL-input compatible | Requires level-shifting when interfacing with LS-TTL sources; unsuitable for drop-in LS-TTL replacement | Choose MM74HCT540WMX for seamless LS-TTL interoperability and proven 3-state timing behavior. |
Compared with SN74HCT540N and 74VHC540M, the MM74HCT540WMX uniquely combines full industrial temperature range, true TTL input compatibility, and verified 3-state timing margins - making it the preferred choice for legacy system upgrades and harsh-environment bus isolation where reliability and compatibility are non-negotiable.
Availability
MM74HCT540WMX is available at Aetrix Electronics and suitable for industrial PLC backplanes, automotive ECU signal routing, and legacy computer system bus isolation requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MM74HCT540WMX 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient, high-reliability components for automotive, industrial, cloud, and IoT applications.
The MM74HCT540WMX belongs to the MM74HCT logic family, engineered specifically to provide TTL-to-CMOS bridging with LS-TTL plug-in replacement capability - targeting cost-sensitive, power-aware upgrades of legacy digital systems.
FAQ
What is the maximum operating temperature range for the MM74HCT540WMX?
The MM74HCT540WMX is fully specified from −55 °C to +125 °C, with all DC and AC electrical characteristics guaranteed across this extended industrial temperature range. This makes the MM74HCT540WMX suitable for under-hood automotive applications and high-reliability industrial control systems where thermal stress is a key design constraint.
Does the MM74HCT540WMX support true TTL input voltage levels?
Yes, the MM74HCT540WMX guarantees VIH = 2.0 V and VIL = 0.8 V across its full operating temperature range, matching LS-TTL input thresholds exactly. This allows direct connection to legacy TTL outputs without level-shifting circuitry - a core design feature confirmed in the onsemi datasheet for the MM74HCT540WMX.
How does the 3-state enable logic work on the MM74HCT540WMX?
The MM74HCT540WMX uses a two-input NOR gate for 3-state control: if either G1 (Pin 1) or G2 (Pin 19) is HIGH, all eight outputs enter high-impedance mode. Only when both G1 and G2 are LOW do the inverting buffers become active. This architecture prevents partial enable states and ensures deterministic bus release timing in the MM74HCT540WMX.
What package type is used for the MM74HCT540WMX?
The MM74HCT540WMX is supplied in a Pb-free SOIC-20 Wide Body (WB) package, case outline 751D-05, with 12.8 mm × 7.5 mm dimensions and 1.27 mm lead pitch. This package is RoHS-compliant, reflow-solder compatible, and matches industry-standard footprints for automated assembly.
Can the MM74HCT540WMX replace LS-TTL devices directly on existing PCBs?
Yes - the MM74HCT540WMX is explicitly designed as a plug-in replacement for LS-TTL octal buffers, with identical pinout, TTL-compatible inputs, and fanout of 15 LS-TTL loads. Its 160 µA max quiescent current and 5 V supply compatibility allow immediate substitution in legacy designs without layout or firmware changes, preserving system functionality while reducing power in the MM74HCT540WMX.
MM74HCT540WMX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74HCT
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- 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:
- 7.2mA, 7.2mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SOIC
MM74HCT540WMX FAQ
1.How can I place an order for MM74HCT540WMX through Aetrix?
Please submit a Request for Quotation (RFQ) for MM74HCT540WMX 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 MM74HCT540WMX reliable?
The price and inventory of MM74HCT540WMX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MM74HCT540WMX is usually 5 days.
3.What payment methods are accepted for MM74HCT540WMX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MM74HCT540WMX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MM74HCT540WMX?
MM74HCT540WMX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MM74HCT540WMX 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 MM74HCT540WMX?
For technical support, including MM74HCT540WMX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MM74HCT540WMX requirements.
6.How does Aetrix verify that MM74HCT540WMX is sourced from the original manufacturer or authorized distributors?
All MM74HCT540WMX 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 MM74HCT540WMX meets industry standards.
7.What is the process for return or replacement of MM74HCT540WMX?
All MM74HCT540WMX units undergo pre-shipment inspection (PSI). If there is an issue with MM74HCT540WMX, 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 MM74HCT540WMX part is unused and in its original packaging.
Return procedure for MM74HCT540WMX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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