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onsemi MM74HCT540WM
- Part No.:
- MM74HCT540WM
- Manufacturer:
- onsemi
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
MM74HCT540WM.pdf
- Description:
- IC BUFFER INVERT 5.5V 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,291
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Product details
Overview
MM74HCT540WM 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 capability, and TTL-compatible input thresholds (VIH = 2.0 V, VIL = 0.8 V), enabling direct replacement of LS-TTL buffers in industrial control backplanes.
For engineers reviewing the MM74HCT540WM datasheet, pinout, applications, or equivalent options, key selection criteria include its inverting logic function, dual 3-state enable inputs (G1/G2 NOR-gated), SOIC-20 Pb-free package, and guaranteed operation across −55 °C to +125 °C.
Technical Context
The MM74HCT540WM implements eight independent inverting buffer channels with a two-input NOR gate controlling all outputs' 3-state behavior: outputs enter high-impedance when either G1 or G2 is HIGH. Its silicon-gate CMOS process ensures TTL-level input compatibility while maintaining CMOS quiescent current efficiency.
Designed for system bus interfacing, it supports CL = 50 pF loads with 20 ns max propagation delay over full temperature range and provides 15 LS-TTL fanout. Input protection diodes to VCC and GND enhance ESD robustness without external components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Function | Inverting octal buffer with 3-state outputs |
| Propagation Delay | 12 ns typical (CL = 50 pF, VCC = 5 V, TA = 25 °C); enables ≤40 MHz bus clocking |
| Output Drive | ±6 mA min at VOL ≤ 0.4 V / VOH ≥ 3.7 V; drives standard LS-TTL loads directly |
| Supply Range | 4.5 V to 5.5 V; compatible with regulated 5 V rails in legacy industrial systems |
| Operating Temp | −55 °C to +125 °C; qualified for under-hood automotive and harsh-environment industrial use |
| Input Compatibility | TTL-level: VIH = 2.0 V, VIL = 0.8 V; eliminates level-shifter requirements in mixed-logic designs |
| Quiescent Current | 160 µA max (TA = −55 °C to +125 °C); reduces standby power in always-on subsystems |
Pinout & Package
MM74HCT540WM is housed in a 20-pin SOIC wide-body (Case 751D-05) package measuring 12.8 mm × 7.5 mm × 2.65 mm, optimized for automated assembly and thermal dissipation in dense PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | 3-State Enable Inputs (G1, G2) | NOR-gated control: either HIGH forces all outputs into high-Z; enables flexible bus arbitration |
| 2–9 | Inputs (A1–A8) | Inverting data inputs; TTL-compatible thresholds allow direct connection to LS-TTL sources |
| 11–18 | Outputs (Y1–Y8) | Inverted buffered outputs with ±35 mA absolute max drive; support hot-swap bus loading |
| 10 | GND | Ground reference for all I/O and internal logic; decoupling capacitor placement critical for noise immunity |
| 20 | VCC | 5 V supply input; requires local 0.1 µF ceramic bypass capacitor per device |
Key Features
| Feature | Design Value |
|---|---|
| 3-State Output Control | Dual-enable NOR architecture allows independent bus direction control without external logic |
| High-Speed Bus Interface | 12 ns typical tPLH/tPHL ensures timing closure in 25–40 MHz address/data buses |
| TTL-Compatible Inputs | VIH/VIL thresholds match LS-TTL exactly, eliminating level translation in legacy upgrades |
| Pb-Free SOIC Package | RoHS-compliant 20-pin SOIC-WB (751D-05) supports lead-free reflow and long-term supply stability |
| Wide Temperature Range | −55 °C to +125 °C operation validated per AEC-Q100 stress profiles for automotive ECUs |
Applications
| Industrial PLC Backplane | Automotive Body Control Module |
|---|---|
|
Use Scenario: Bidirectional data routing between microcontroller and I/O expansion cards in modular PLC racks. IC Role / Device Role / Timing Role: Inverting 3-state buffer isolating CPU address/data bus from peripheral slots during read/write cycles. Use Value: Enables deterministic bus turnaround with 25 ns max disable time (tPLZ/tPHZ), preventing data contention during slot switching. |
Use Scenario: Level-shifting and buffering between 5 V MCU GPIOs and LIN transceiver control lines in door module ECUs. IC Role / Device Role / Timing Role: Inverting interface buffer driving LIN enable/disable signals with TTL-compatible input thresholds. Use Value: Eliminates discrete level shifters; guaranteed −55 °C to +125 °C operation ensures reliability in cabin temperature extremes. |
| Legacy Instrumentation Upgrade | Test Equipment Signal Conditioning |
|
Use Scenario: Replacing obsolete 74LS540 in aging benchtop oscilloscope trigger path redesign. IC Role / Device Role / Timing Role: Pin-compatible drop-in replacement providing identical inverting buffer function with lower power draw. Use Value: Reduces quiescent current from ~25 mA (LS-TTL) to 160 µA, cutting board-level standby power by >99%. |
Use Scenario: Driving multiple parallel test fixture relays from a single FPGA I/O bank in automated test systems. IC Role / Device Role / Timing Role: Octal buffer distributing inverted control signals to relay drivers while isolating FPGA pins from relay coil inductance. Use Value: ±6 mA drive per output ensures fast relay actuation; 3-state capability allows shared control bus among multiple fixtures. |
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 SOIC-20 package; TI version has 20 ns max tPLH at CL = 50 pF (vs. 25 ns for MM74HCT540WM at same condition) | Validated for commercial temp range only (0 °C to +70 °C); not rated for extended industrial or automotive use | Select when cost sensitivity outweighs extended temperature requirement and sourcing flexibility is needed |
| 74VHC540M | Higher speed (7.5 ns typ propagation), but 2 V to 5.5 V supply range and non-TTL input thresholds (VIH = 0.7×VCC) | Requires input voltage scaling for LS-TTL source compatibility; unsuitable for direct LS-TTL drop-in replacement | Choose only when upgrading entire system to VHC logic family and redesigning input interface circuitry |
Compared with SN74HCT540N and 74VHC540M, the MM74HCT540WM uniquely combines LS-TTL input compatibility, −55 °C to +125 °C qualification, and Pb-free SOIC packaging-making it the sole option for drop-in replacement in legacy high-reliability industrial and automotive bus interfaces.
Availability
MM74HCT540WM is available at Aetrix Electronics and suitable for industrial PLC backplanes, automotive body control modules, legacy instrumentation upgrades, and test equipment signal conditioning requiring stable component supply across extended temperature ranges.
Supply support for MM74HCT540WM 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 power, analog, sensor, and logic solutions for automotive, industrial, and cloud infrastructure markets.
The MM74HCT540WM belongs to the HCT logic family engineered for seamless TTL-to-CMOS interfacing, targeting cost-sensitive, high-reliability replacements in legacy industrial and automotive electronic control units.
FAQ
What logic function does the MM74HCT540WM implement?
The MM74HCT540WM implements an octal inverting 3-state buffer function. Each of its eight channels accepts a digital input (A1–A8), inverts it, and presents the result at the corresponding output (Y1–Y8). All outputs enter high-impedance state when either G1 or G2 enable input is HIGH, as defined by a NOR logic relationship. This behavior is explicitly confirmed in the General Description and Connection Diagram sections of the onsemi datasheet for MM74HCT540WM.
Is the MM74HCT540WM pin-compatible with the 74LS540?
Yes, the MM74HCT540WM is a direct pin-compatible replacement for the 74LS540 in SOIC-20 packages. Both devices share identical pin assignments for inputs (pins 2–9), outputs (pins 11–18), enables (pins 1 and 19), VCC (pin 20), and GND (pin 10), as verified in the Connection Diagrams section of the onsemi datasheet. This allows drop-in substitution without PCB layout changes.
What is the maximum operating temperature range for the MM74HCT540WM?
The MM74HCT540WM is specified for continuous operation from −55 °C to +125 °C, as stated in the Recommended Operating Conditions table of the onsemi datasheet. This extended temperature range is validated across all DC and AC electrical characteristics, making it suitable for under-hood automotive applications and industrial environments where ambient temperatures exceed commercial-grade limits.
Does the MM74HCT540WM require external pull-up or pull-down resistors on its enable inputs?
No, the MM74HCT540WM does not require external pull-up or pull-down resistors on G1 or G2 enable inputs. Its CMOS input structure exhibits extremely low leakage (±1.0 µA max), and the datasheet specifies valid logic thresholds (VIH = 2.0 V, VIL = 0.8 V) that are fully compatible with standard TTL and CMOS output levels. Floating inputs are not permitted, but active drive from system logic suffices.
What package type is used for the MM74HCT540WM?
The MM74HCT540WM uses a 20-pin SOIC wide-body (SOIC-WB) package, designated Case 751D-05 by onsemi. Its dimensions are 12.8 mm × 7.5 mm × 2.65 mm, with 1.27 mm pitch, and it is Pb-free and RoHS compliant, as confirmed in the Ordering Information and Package Dimensions sections of the official datasheet.
MM74HCT540WM Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74HCT
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- 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:
- 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
MM74HCT540WM FAQ
1.How can I place an order for MM74HCT540WM through Aetrix?
Please submit a Request for Quotation (RFQ) for MM74HCT540WM 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 MM74HCT540WM reliable?
The price and inventory of MM74HCT540WM are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MM74HCT540WM is usually 5 days.
3.What payment methods are accepted for MM74HCT540WM?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MM74HCT540WM transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MM74HCT540WM?
MM74HCT540WM orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MM74HCT540WM 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 MM74HCT540WM?
For technical support, including MM74HCT540WM datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MM74HCT540WM requirements.
6.How does Aetrix verify that MM74HCT540WM is sourced from the original manufacturer or authorized distributors?
All MM74HCT540WM 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 MM74HCT540WM meets industry standards.
7.What is the process for return or replacement of MM74HCT540WM?
All MM74HCT540WM units undergo pre-shipment inspection (PSI). If there is an issue with MM74HCT540WM, 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 MM74HCT540WM part is unused and in its original packaging.
Return procedure for MM74HCT540WM:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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