My Inquiry
My Account
onsemi MM74HC540MTC
- Part No.:
- MM74HC540MTC
- Manufacturer:
- onsemi
- Package:
- 20-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
MM74HC540MTC.pdf
- Description:
- IC BUFFER INVERT 6V 20TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:619
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MM74HC540MTC from ON Semiconductor is an inverting octal 3-STATE buffer IC designed for bidirectional bus interface and data routing in digital systems. It features 8 inverting buffered outputs, 3-STATE control via dual-input NOR logic (G1/G2), operates across 2–6 V supply, delivers 6 mA output drive, and achieves 12 ns typical propagation delay at 4.5 V with 50 pF load - enabling high-speed bus driving in industrial controllers and embedded peripherals.
For engineers reviewing the MM74HC540MTC datasheet, pinout, applications, or equivalent options, key selection considerations include its inverting logic function, TSSOP-20 package footprint, 3-STATE enable timing (tPZH/tPHZ ≤28/25 ns), input voltage thresholds (VIH=3.15 V min at VCC=4.5 V), and compatibility with LS-TTL fanout (15 loads).
Technical Context
The MM74HC540MTC implements advanced silicon-gate CMOS technology to deliver high noise immunity and low quiescent current (≤80 µA at 6 V), while maintaining speed comparable to low-power Schottky TTL. Its dual 3-STATE enable inputs (G1, G2) form a NOR gate - asserting either high forces all eight outputs into high-impedance state, supporting shared-bus arbitration.
Input protection diodes to VCC and GND prevent static damage, and the pinout places all eight inputs on one side and all eight outputs on the opposite side of the TSSOP-20 package - optimizing PCB layout for parallel bus routing without layer crossover.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Function | Inverting octal buffer with independent 3-STATE control |
| Supply Voltage Range | 2.0–6.0 V - supports mixed-voltage system interfacing (e.g., 3.3 V microcontroller to 5 V peripheral bus) |
| Propagation Delay | 12 ns typical (tPLH/tPHL, VCC=4.5 V, CL=50 pF) - enables >30 MHz bus operation in synchronous designs |
| Output Drive | ±6 mA (IOH/IOL) - sufficient to drive 15 LS-TTL inputs or 50 pF transmission line loads |
| 3-STATE Enable Time | tPZH ≤28 ns (VCC=4.5 V, CL=45 pF) - ensures fast bus release for time-critical arbitration |
| Input Thresholds | VIH = 3.15 V min, VIL = 1.35 V max (VCC=4.5 V) - provides 1.1 V noise margin against LS-TTL-compatible signals |
| Quiescent Current | ≤80 µA max (ICC, VCC=6 V) - enables low-power standby in battery-backed systems |
Pinout & Package
MM74HC540MTC uses a 20-lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153 compliant, 4.4 mm body width, 0.65 mm lead pitch, and exposed pad not electrically connected. Pin numbering follows standard TSSOP convention with Pin 1 marked by dot or bevel.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (G1) | 3-STATE Enable Input A | NOR-gated enable: HIGH disables all outputs regardless of G2 or data inputs |
| 2 (1A) | Input A1 | Inverts and buffers to Y1; compatible with 5 V tolerant CMOS/TTL logic levels |
| 3 (1Y) | Output Y1 | Inverted output of 1A; 3-STATE when G1 or G2 HIGH |
| 4 (2A) | Input A2 | Inverts and buffers to Y2; identical electrical behavior to 1A |
| 5 (2Y) | Output Y2 | Inverted output of 2A; shares same 3-STATE control as all other Y pins |
| 6 (3A) | Input A3 | Third inverting input channel; supports daisy-chained or parallel bus expansion |
| 7 (3Y) | Output Y3 | Third inverted output; maintains consistent timing with other Y outputs |
| 8 (4A) | Input A4 | Fourth inverting input; enables full octal data path coverage |
| 9 (4Y) | Output Y4 | Fourth inverted output; pinout symmetry simplifies PCB trace routing |
| 10 (G2) | 3-STATE Enable Input B | Second NOR input: HIGH (with G1 LOW) also forces all outputs to high-Z |
| 11 (5Y) | Output Y5 | Fifth inverted output; placed opposite inputs to minimize signal crosstalk |
| 12 (5A) | Input A5 | Fifth inverting input; matches timing and drive strength of A1–A4 |
| 13 (6Y) | Output Y6 | Sixth inverted output; supports bidirectional bus direction control |
| 14 (6A) | Input A6 | Sixth inverting input; allows full 8-bit data inversion without external logic |
| 15 (7Y) | Output Y7 | Seventh inverted output; enables compact 8-bit address/data bus buffering |
| 16 (7A) | Input A7 | Seventh inverting input; supports legacy 8-bit microprocessor bus interfaces |
| 17 (8Y) | Output Y8 | Eighth inverted output; completes octal channel set for full byte handling |
| 18 (8A) | Input A8 | Eighth inverting input; matches AC/DC specs across all channels |
| 19 (VCC) | Positive Supply | 2.0–6.0 V power rail; decoupling capacitor required within 5 mm for stable switching |
| 20 (GND) | Ground Reference | Signal and power return; must connect to low-impedance ground plane |
Key Features
| Feature | Design Value |
|---|---|
| Inverting octal buffer with dual 3-STATE control | Enables bidirectional bus isolation using single device - eliminates need for discrete enable logic or multiple buffers |
| High-speed CMOS performance (12 ns typ) | Meets timing requirements of 8-bit microcontrollers (e.g., 8051, PIC18) operating at ≥20 MHz system clocks |
| Wide 2–6 V supply range | Supports direct interfacing between 3.3 V FPGAs and 5 V legacy peripherals without level shifters |
| Input protection diodes to VCC/GND | Withstands ±2 kV HBM ESD without external clamping - reduces board-level protection component count |
| Pinout with inputs/outputs on opposite sides | Minimizes PCB trace length and crosstalk in parallel bus layouts - improves signal integrity up to 50 MHz |
Applications
| Industrial PLC I/O Expansion | Legacy Microprocessor Bus Interface |
|---|---|
|
Use Scenario: Adding isolated digital input/output modules to programmable logic controllers using 24 V field sensors and 5 V backplane buses. IC Role / Device Role / Timing Role: Inverting buffer isolating sensor data lines and enabling 3-STATE bus sharing among multiple I/O cards. Use Value: Dual enable inputs allow centralized bus arbitration; 6 mA drive sustains signal integrity over 30 cm ribbon cables. |
Use Scenario: Interfacing Z80 or 8085 CPUs with external memory or peripheral chips requiring inverted address/data strobes. IC Role / Device Role / Timing Role: Octal inverting buffer providing controlled signal inversion and bus contention prevention during memory read/write cycles. Use Value: 12 ns propagation delay meets Z80 tAVQV ≤ 200 ns timing budget; TSSOP-20 footprint saves space vs. PDIP alternatives. |
| Embedded System Address Latching | Test Equipment Signal Conditioning |
|
Use Scenario: Latching 8-bit address segments in ARM Cortex-M based debug probes where address lines must be inverted before latch capture. IC Role / Device Role / Timing Role: Inverting buffer driving address latch enable signals with precise 3-STATE control synchronized to clock edges. Use Value: tPZH ≤28 ns ensures clean enable assertion before latch setup time; 2–6 V operation matches probe's mixed-supply architecture. |
Use Scenario: Conditioning digital stimulus signals in automated test equipment (ATE) where waveform polarity must be inverted prior to DUT connection. IC Role / Device Role / Timing Role: Precision inverting buffer delivering matched delay across all 8 channels for phase-aligned signal generation. Use Value: Channel-to-channel skew <1 ns (per datasheet AC specs) preserves timing alignment across multi-pin DUT interfaces. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal inverting buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HC540N | Same logic function and AC/DC specs, but in PDIP-20 package (1.27 mm pitch, 6.35 mm width) | Preferred for through-hole prototyping or legacy board rework where TSSOP reflow is unavailable | Select SN74HC540N only if manual soldering or socket-based testing is required; no pinout change needed |
| 74LVX540MTCX | Lower voltage range (2.7–3.6 V), higher speed (8 ns typ), but incompatible with 5 V systems | Optimized for 3.3 V-only portable electronics; lacks 5 V tolerance on inputs/outputs | Choose 74LVX540MTCX only in pure 3.3 V domains; MM74HC540MTC remains necessary for mixed-voltage or 5 V legacy support |
Compared with SN74HC540N and 74LVX540MTCX, the MM74HC540MTC uniquely balances 2–6 V operation, TSSOP-20 space efficiency, and proven interoperability with both LS-TTL and modern CMOS buses - making it the default choice for industrial and mixed-supply embedded designs.
Availability
MM74HC540MTC is available at Aetrix Electronics and suitable for industrial automation, embedded controller design, and legacy system upgrades requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.
Supply support for MM74HC540MTC 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
ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power management, analog, logic, and sensor solutions for automotive, industrial, and cloud infrastructure applications.
The MM74HC540MTC belongs to ON Semiconductor's legacy HC logic family - engineered for robustness, wide-voltage interoperability, and drop-in replacement of obsolete TTL and earlier CMOS buffers in industrial control and instrumentation systems.
FAQ
What is the logic function of the MM74HC540MTC?
The MM74HC540MTC is an inverting octal 3-STATE buffer: it accepts eight digital inputs (A1–A8), inverts each, and drives corresponding outputs (Y1–Y8). All outputs enter high-impedance state when either G1 or G2 enable input is HIGH. This function is confirmed in the Fairchild DS005341 datasheet and applies specifically to the MM74HC540MTC variant in TSSOP-20 packaging.
Does the MM74HC540MTC support 3.3 V operation?
Yes, the MM74HC540MTC operates across 2.0–6.0 V, including standard 3.3 V supply rails. At VCC = 3.3 V, VIH is guaranteed ≥2.1 V and VOL ≤0.33 V at 6 mA load - ensuring reliable interfacing with 3.3 V microcontrollers and FPGAs. These values are specified in the DC Electrical Characteristics table of the official datasheet.
What is the maximum output current per pin for the MM74HC540MTC?
The MM74HC540MTC delivers ±6 mA DC output current per pin (IOL/IOH) under guaranteed conditions at VCC = 4.5 V and TA = 25 °C. Absolute maximum ratings allow ±35 mA short-term, but sustained operation above ±6 mA risks exceeding VOH/VOL limits and thermal derating - verified in the DC Electrical Characteristics section of DS005341.
Is the MM74HC540MTC pin-compatible with the MM74HC541MTC?
No, the MM74HC540MTC is not pin-compatible with the MM74HC541MTC. Although both share identical TSSOP-20 packaging and pin count, their logic functions differ: MM74HC540MTC is inverting, while MM74HC541MTC is non-inverting. Swapping them causes functional inversion errors - confirmed by the "General Description" and connection diagrams in DS005341.
What package type does the MM74HC540MTC use?
The MM74HC540MTC uses a 20-lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153 compliant, with 4.4 mm body width and 0.65 mm lead pitch. This is explicitly stated in the "Ordering Code" table of DS005341 under "MM74HC540MTC / MTC20", and distinct from SOIC (M20B) or PDIP (N20A) variants.
MM74HC540MTC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74HC
- Package/Case:
- 20-TSSOP (0.173", 4.40mm 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:
- 7.8mA, 7.8mA
- Voltage - Supply:
- 2V ~ 6V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-TSSOP
MM74HC540MTC FAQ
1.How can I place an order for MM74HC540MTC through Aetrix?
Please submit a Request for Quotation (RFQ) for MM74HC540MTC 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 MM74HC540MTC reliable?
The price and inventory of MM74HC540MTC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MM74HC540MTC is usually 5 days.
3.What payment methods are accepted for MM74HC540MTC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MM74HC540MTC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MM74HC540MTC?
MM74HC540MTC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MM74HC540MTC 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 MM74HC540MTC?
For technical support, including MM74HC540MTC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MM74HC540MTC requirements.
6.How does Aetrix verify that MM74HC540MTC is sourced from the original manufacturer or authorized distributors?
All MM74HC540MTC 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 MM74HC540MTC meets industry standards.
7.What is the process for return or replacement of MM74HC540MTC?
All MM74HC540MTC units undergo pre-shipment inspection (PSI). If there is an issue with MM74HC540MTC, 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 MM74HC540MTC part is unused and in its original packaging.
Return procedure for MM74HC540MTC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MM74HC540MTC 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…
