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onsemi MM74HCT240MTC
- Part No.:
- MM74HCT240MTC
- Manufacturer:
- onsemi
- Package:
- 20-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
MM74HCT240MTC.pdf
- Description:
- IC BUFFER INVERT 5.5V 20TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,901
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Product details
Overview
MM74HCT240MTC from onsemi is an inverting octal 3-STATE buffer IC designed for TTL-to-CMOS bus interfacing, featuring dual active-low enables (1G, 2G), 14 ns typical propagation delay at 5 V, ±6 mA output drive per pin, and TTL-compatible inputs. It operates across −55 °C to +125 °C and supports high-capacitance system buses in industrial control backplanes.
For engineers reviewing the MM74HCT240MTC datasheet, pinout, applications, or equivalent options, key selection criteria include inverting logic polarity, dual independent enable control, 3-STATE output compatibility with shared data buses, and Pb-free TSSOP-20 packaging for space-constrained PCB layouts.
Technical Context
The MM74HCT240MTC implements two groups of four inverting buffers, each controlled by its own active-low enable (1G controls Y1–Y4; 2G controls Y5–Y8). All outputs enter high-impedance state when their respective enable is HIGH, enabling bidirectional bus arbitration without external logic.
It uses silicon-gate CMOS technology with TTL-level input thresholds (VIH = 2.0 V min, VIL = 0.8 V max), achieves 160 µA max quiescent ICC, and maintains guaranteed AC performance up to 125 °C with CL = 50 pF loading - critical for legacy bus upgrades requiring drop-in low-power replacement.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Function | Inverting octal buffer with dual active-low enables (1G, 2G) |
| Propagation Delay | 14 ns typical (CL = 50 pF, VCC = 5 V, TA = 25 °C) - ensures timing compliance in 20 MHz bus systems |
| Output Drive | ±6 mA min per pin (VCC = 4.5 V) - drives ≥15 LS-TTL loads or 45 pF bus capacitance reliably |
| Supply Range | 4.5 V to 5.5 V - compatible with standard 5 V TTL/CMOS rails; no level-shifting required |
| Operating Temp | −55 °C to +125 °C - qualified for extended industrial and automotive under-hood environments |
| Quiescent ICC | 160 µA max (VIN = VCC/GND) - enables low-static-power operation in always-on subsystems |
| Input Compatibility | TTL-level (VIH ≥ 2.0 V, VIL ≤ 0.8 V) - interfaces directly with 74LS, 74ALS, and microcontroller GPIOs |
Pinout & Package
TSSOP-20 package (Case 948AQ), 4.4 mm × 6.5 mm body, 0.65 mm pitch, Pb-free, moisture sensitivity level 1 (MSL1).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | 1G, 2G (Enable Inputs) | Active-low enables for first and second buffer groups; HIGH disables corresponding outputs to high-Z |
| 2–5, 13–16 | 1A–4A, 5A–8A (Inputs) | Inverting data inputs; each drives one buffered output with polarity inversion |
| 6–9, 11–14 | 1Y–4Y, 5Y–8Y (Outputs) | 3-STATE inverting outputs; LOW input → HIGH output (and vice versa) when enabled |
| 10 | GND | Ground reference for all logic and power domains |
| 20 | VCC | +5 V supply rail; decoupling capacitor required within 10 mm of pin |
Key Features
| Feature | Design Value |
|---|---|
| Inverting logic with dual enables | Enables independent control of two 4-bit data paths - simplifies address/data bus gating without glue logic |
| 3-STATE outputs | High-impedance outputs eliminate bus contention in multi-driver systems - essential for shared memory or peripheral buses |
| TTL-compatible inputs | Accepts standard 5 V TTL voltage levels without external resistors or level shifters - reduces BOM count |
| Low quiescent current | 160 µA max ICC allows use in battery-backed or energy-sensitive modules where standby leakage matters |
| Pb-free TSSOP-20 | RoHS-compliant, fine-pitch package supports high-density routing and automated SMT assembly |
Applications
| Industrial PLC Backplane Interface | Legacy Microprocessor Bus Extender |
|---|---|
|
Use Scenario: Interfacing a modern microcontroller's GPIO bank to a legacy 8-bit parallel bus in programmable logic controllers. IC Role / Device Role / Timing Role: Inverting buffer with dual enables isolates MCU pins from bus noise while providing direction-controlled data latching. Use Value: Enables direct connection to LS-TTL peripherals without level shifters; 14 ns delay preserves setup/hold timing for 20 MHz bus cycles. |
Use Scenario: Expanding address/data bus drive capability in retro computing systems using Z80 or 8085 CPUs. IC Role / Device Role / Timing Role: Octal inverting buffer with 3-STATE outputs acts as bus transceiver for memory-mapped I/O expansion cards. Use Value: ±6 mA drive sustains signal integrity over 15 cm ribbon cables; dual enables allow selective activation of I/O banks. |
| Automotive Body Control Module | Test Equipment Signal Conditioning |
|
Use Scenario: Level translation and buffering between 3.3 V MCU I/O and 5 V sensor interface circuits in under-hood ECUs. IC Role / Device Role / Timing Role: Inverting buffer provides noise-immune signal conditioning for switch inputs and LED drivers. Use Value: −55 °C to +125 °C rating ensures reliability in engine bay environments; TTL input thresholds tolerate noisy 5 V supply rails. |
Use Scenario: Isolating DUT signals from test fixture wiring in automated functional testers for digital boards. IC Role / Device Role / Timing Role: 3-STATE buffer gates test signals onto shared probe buses, preventing back-driving during calibration sequences. Use Value: High-impedance disable state eliminates crosstalk; 160 µA ICC minimizes fixture self-heating during long-duration tests. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar inverting octal buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HCT240PW | TSSOP-20, identical logic and DC specs; TI version has slightly higher VOL (0.4 V max vs 0.33 V) at −55 °C to +125 °C | Same pinout and function; validated for TI-based designs with existing layout | Select if sourcing from TI-authorized channels or requiring TI-specific qualification documentation |
| 74HCT240D,653 | SOIC-20 package (7.5 mm wide); same electrical specs but larger footprint and lower thermal dissipation (833 mW vs 1302 mW SOIC) | Better suited for through-hole prototyping or legacy board rework where TSSOP reflow is unavailable | Select when manual soldering, mixed-technology assembly, or mechanical robustness outweighs space constraints |
Compared with SN74HCT240PW and 74HCT240D,653, the MM74HCT240MTC offers identical inverting octal 3-STATE functionality in a compact Pb-free TSSOP-20, optimized for high-density industrial PCBs requiring extended temperature operation and low static power - making it ideal for new designs prioritizing miniaturization and RoHS compliance.
Availability
MM74HCT240MTC is available at Aetrix Electronics and suitable for industrial PLC backplanes, automotive body control modules, and test equipment signal conditioning requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for MM74HCT240MTC 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, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The MM74HCT240MTC belongs to onsemi's HCT logic family - engineered for seamless TTL-to-CMOS interfacing with low power consumption, high noise immunity, and extended temperature operation in mission-critical embedded systems.
FAQ
What is the logic function of the MM74HCT240MTC?
The MM74HCT240MTC is an inverting octal 3-STATE buffer with two independent active-low enable inputs (1G and 2G). Each enable controls four inverting buffers: 1G enables Y1–Y4 (inverted versions of A1–A4), and 2G enables Y5–Y8 (inverted versions of A5–A8). When an enable is HIGH, its corresponding outputs go to high-impedance state.
Does the MM74HCT240MTC support 3.3 V logic inputs?
No - the MM74HCT240MTC is not guaranteed to recognize 3.3 V as a valid HIGH input. Its VIH minimum is 2.0 V at VCC = 4.5–5.5 V, but input thresholds are TTL-compatible and optimized for 5 V systems. Driving it from 3.3 V logic may result in marginal or non-functional operation unless VCC is reduced to match, which violates recommended operating conditions.
What is the maximum capacitive load the MM74HCT240MTC can drive reliably?
The MM74HCT240MTC is characterized for CL = 50 pF and CL = 150 pF loads in its AC Electrical Characteristics table. At CL = 150 pF and VCC = 5 V, propagation delay increases to 42 ns max (TA = −55 °C to +125 °C), confirming reliable operation up to 150 pF per output - sufficient for most 8-bit parallel buses with moderate trace length and stub count.
Is the MM74HCT240MTC pin-compatible with the MM74HCT244MTC?
No - the MM74HCT240MTC and MM74HCT244MTC have identical pinouts in TSSOP-20, but differ in logic function: MM74HCT240MTC is inverting, while MM74HCT244MTC is non-inverting. Swapping them without logic redesign will invert all eight data bits, causing functional failure in most applications.
What thermal considerations apply to the MM74HCT240MTC in TSSOP-20 package?
The MM74HCT240MTC in TSSOP-20 (Case 948AQ) has a power dissipation limit of 833 mW at TA = 25 °C. With max ICC = 160 µA and typical dynamic power <1 mW per buffer, thermal stress is dominated by output switching. For sustained 6 mA sink/source operation, ensure copper pour under pin 10 (VCC) and pin 10 (GND) and maintain ambient <85 °C to stay within junction temperature limits.
MM74HCT240MTC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74HCT
- Package/Case:
- 20-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Logic Type:
- Buffer, Inverting
- Number of Elements:
- 2
- Number of Bits per Element:
- 4
- 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-TSSOP
MM74HCT240MTC FAQ
1.How can I place an order for MM74HCT240MTC through Aetrix?
Please submit a Request for Quotation (RFQ) for MM74HCT240MTC 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 MM74HCT240MTC reliable?
The price and inventory of MM74HCT240MTC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MM74HCT240MTC is usually 5 days.
3.What payment methods are accepted for MM74HCT240MTC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MM74HCT240MTC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MM74HCT240MTC?
MM74HCT240MTC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MM74HCT240MTC 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 MM74HCT240MTC?
For technical support, including MM74HCT240MTC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MM74HCT240MTC requirements.
6.How does Aetrix verify that MM74HCT240MTC is sourced from the original manufacturer or authorized distributors?
All MM74HCT240MTC 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 MM74HCT240MTC meets industry standards.
7.What is the process for return or replacement of MM74HCT240MTC?
All MM74HCT240MTC units undergo pre-shipment inspection (PSI). If there is an issue with MM74HCT240MTC, 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 MM74HCT240MTC part is unused and in its original packaging.
Return procedure for MM74HCT240MTC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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