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onsemi MM74HC245ASJX
- Part No.:
- MM74HC245ASJX
- Manufacturer:
- onsemi
- Package:
- 20-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
MM74HC245ASJX.pdf
- Description:
- IC TXRX NON-INVERT 6V 20SOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,730
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Product details
Overview
MM74HC245ASJX from ON Semiconductor is an octal 3-STATE bidirectional transceiver in a 20-lead SOP package (EIAJ TYPE II, 5.3 mm wide), designed for asynchronous bus-to-bus communication. It operates from 2–6 V, delivers ≥6 mA output drive per pin, exhibits 13 ns typical propagation delay at 4.5 V, and supports true data transfer with active-low enable (G) and direction control (DIR). It is used in industrial control backplanes and legacy microprocessor data bus interfaces.
For engineers reviewing the MM74HC245ASJX datasheet, pinout, applications, or equivalent options, key selection criteria include its 20-pin SOP footprint, bidirectional 3-STATE logic compatibility with HC-family timing, bus capacitance drive capability up to 15 LS-TTL loads, and absence of Schmitt-trigger inputs.
Technical Context
The MM74HC245ASJX implements a dual-rail CMOS transceiver architecture with separate A- and B-side I/O banks, enabling configurable data flow direction via the DIR input. Its 3-STATE outputs are controlled by an active-low G signal, allowing bus isolation during disable states without contention.
It uses silicon-gate CMOS technology to achieve TTL-compatible speed (13 ns typical tPHL/tPLH at VCC = 4.5 V, CL = 50 pF) while maintaining low quiescent current (≤80 µA max at 6 V) and high noise immunity. Input protection diodes clamp to VCC and GND for ESD robustness.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2–6 V - supports mixed-voltage system interfacing (e.g., 3.3 V ↔ 5 V buses) |
| Propagation Delay (tPHL/tPLH) | 13 ns typical at 4.5 V, 50 pF - enables reliable operation up to ~30 MHz bus toggle rates |
| Output Drive Strength | ≥6 mA sink/source per pin - sufficient to drive 15 LS-TTL loads without external buffering |
| 3-STATE Enable/Disable Time | tPZH/tPZL ≤35 ns, tPHZ/tPLZ ≤25 ns at 4.5 V - ensures fast bus arbitration and minimal bus turnaround latency |
| Input Voltage Thresholds | VIH = 3.15 V, VIL = 1.35 V at 4.5 V - provides 1.35 V noise margin under worst-case conditions |
| Quiescent Supply Current | ≤80 µA max at 6 V - minimizes standby power in battery-backed or low-power hold modes |
Pinout & Package
MM74HC245ASJX is housed in a 20-lead Small Outline Package (SOP), EIAJ TYPE II, 5.3 mm wide (Package Number M20D), with gull-wing leads and standard 0.65 mm pitch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A1–A8 | Input/Output Port A | Bidirectional data terminals connected to first bus; driven high/low or placed in high-impedance state based on G and DIR |
| B1–B8 | Input/Output Port B | Bidirectional data terminals connected to second bus; direction relative to A side determined by DIR state |
| G | Active-Low Output Enable | When LOW, enables transceiver function; when HIGH, forces all A/B outputs into 3-STATE (high-Z) |
| DIR | Direction Control | When HIGH, data flows A→B; when LOW, data flows B→A - no internal latching, synchronous with G |
| VCC | Positive Supply | Power rail for logic core and I/O buffers; must be decoupled locally due to switching current transients |
| GND | Ground Reference | Common return path for supply and signal currents; requires low-inductance connection to minimize ground bounce |
Key Features
| Feature | Design Value |
|---|---|
| True bidirectional data transfer | Supports A→B or B→A flow without inversion - preserves logic polarity across both directions |
| High-speed CMOS performance | 13 ns typical propagation delay matches LS-TTL timing while consuming <1% of its power |
| Wide supply voltage range | 2–6 V operation allows direct interface with 3.3 V microcontrollers and 5 V peripheral buses |
| Bus-compatible 3-STATE outputs | Outputs fully disconnect from bus when disabled - prevents contention in multi-driver shared-bus systems |
Applications
| Industrial Backplane Interface | Legacy Microprocessor Bus Extension |
|---|---|
Use Scenario: Interfacing a 32-bit CPU local bus to a slower 8-bit peripheral expansion bus in programmable logic controllers. IC Role / Device Role / Timing Role: Bidirectional level-shifting transceiver managing data flow direction and bus isolation during DMA cycles. Use Value: Enables seamless 8-bit data exchange between mismatched bus widths and speeds without glue logic or clock domain crossing circuitry. | Use Scenario: Adding external RAM or ROM to an 8085/8088-based embedded controller using a shared address/data bus. IC Role / Device Role / Timing Role: Octal 3-STATE buffer isolating memory data lines during I/O operations and enabling bidirectional program/data transfers. Use Value: Eliminates need for separate unidirectional drivers and simplifies PCB routing with single-directional trace runs. |
| Test Equipment Signal Routing | Automated Test Fixture Data Multiplexing |
Use Scenario: Routing DUT signals between multiple instrument channels in benchtop ATE systems with manual or software-controlled path selection. IC Role / Device Role / Timing Role: Configurable bidirectional signal conduit controlled via microcontroller GPIOs (G and DIR). Use Value: Provides deterministic, low-latency signal path reconfiguration without mechanical relays or analog switches. | Use Scenario: Sharing a single JTAG or UART debug port across multiple PCBs under test in production burn-in fixtures. IC Role / Device Role / Timing Role: Directionally gated data repeater that prevents bus contention when multiple DUTs attempt simultaneous access. Use Value: Reduces fixture component count and eliminates risk of signal collision during parallel test execution. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HC245N | Same logic function and AC/DC specs; packaged in PDIP (N20A) instead of SOP (M20D); slightly higher tPHL/tPLH (15 ns typ at 4.5 V) | Preferred for through-hole prototyping or legacy board repair where SOP rework is impractical | Select SN74HC245N only when PDIP mounting is required; not drop-in compatible with MM74HC245ASJX's SOP footprint |
| 74VHC245SJX | Higher speed (8 ns typ tPHL/tPLH at 4.5 V), lower ICC (≤2 µA), but narrower VCC range (2–5.5 V); identical SOP-20 pinout and logic behavior | Suitable for high-frequency bus extensions where sub-10 ns timing margins are critical | 74VHC245SJX is a functional and pinout-compatible upgrade if VCC ≤5.5 V and faster propagation is needed |
Compared with SN74HC245N and 74VHC245SJX, the MM74HC245ASJX offers optimal balance of speed, power, and 6 V tolerance in SOP packaging - making it ideal for industrial designs requiring robust 5 V operation and surface-mount assembly.
Availability
MM74HC245ASJX is available at Aetrix Electronics and suitable for industrial backplane interfaces, legacy microprocessor bus extensions, and automated test fixture data multiplexing requiring stable component supply and long-term obsolescence management.
Supply support for MM74HC245ASJX 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 markets.
The MM74HC245ASJX belongs to ON Semiconductor's legacy HC logic family, engineered for robust, low-power bidirectional bus interfacing in industrial control, instrumentation, and retro-computing applications.
FAQ
What is the operating temperature range for the MM74HC245ASJX?
The MM74HC245ASJX is rated for operation from –40 °C to +85 °C ambient temperature. This industrial-grade range ensures reliability in factory automation, motor control enclosures, and outdoor instrumentation environments where thermal cycling occurs. The device's DC and AC specifications are guaranteed across this full range, with parameters such as VOH, VOL, and propagation delay validated at both extremes per the datasheet.
Does the MM74HC245ASJX have Schmitt-trigger inputs?
No, the MM74HC245ASJX does not incorporate Schmitt-trigger inputs. Its input thresholds are standard CMOS levels (VIH = 3.15 V, VIL = 1.35 V at VCC = 4.5 V), with no hysteresis. This means clean, monotonic input transitions are required - slow-rising or noisy signals may cause metastability or increased dynamic power consumption. External RC filtering or dedicated Schmitt-trigger buffers should be used if driving from slow or noisy sources.
What is the maximum capacitive load the MM74HC245ASJX can drive reliably?
The MM74HC245ASJX is characterized to drive up to 15 LS-TTL loads, equivalent to approximately 450 pF total bus capacitance (30 pF per LS-TTL input × 15). At 4.5 V supply and 50 pF load, its typical propagation delay is 13 ns; delay increases to 22 ns at 150 pF. For loads exceeding 150 pF, signal integrity analysis and possible series termination or driver staging should be performed before final design sign-off.
Can the MM74HC245ASJX operate at 3.3 V supply voltage?
Yes, the MM74HC245ASJX operates over a 2–6 V supply range, including 3.3 V nominal systems. At 3.3 V, VIH is 2.31 V and VIL is 0.99 V, providing 0.99 V noise margin. Propagation delay increases to ~20 ns (typical) at 3.3 V/50 pF, and output drive drops to ~4 mA. It remains fully compatible with 3.3 V LVTTL and mixed-voltage interfaces when paired with appropriate level translation on control lines (G, DIR).
Is the MM74HC245ASJX pinout compatible with the SN74HC245N?
Yes, the MM74HC245ASJX and SN74HC245N share identical pin functions and numbering across all 20 pins - both follow JEDEC-standard 20-pin transceiver layout. However, they differ in package: MM74HC245ASJX uses SOP (M20D), while SN74HC245N uses PDIP (N20A). Physical replacement requires PCB footprint adaptation; electrical and logic behavior are interchangeable when mounted in their respective packages.
MM74HC245ASJX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74HC
- Package/Case:
- 20-SOIC (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Logic Type:
- Transceiver, Non-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-SOP
MM74HC245ASJX FAQ
1.How can I place an order for MM74HC245ASJX through Aetrix?
Please submit a Request for Quotation (RFQ) for MM74HC245ASJX 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 MM74HC245ASJX reliable?
The price and inventory of MM74HC245ASJX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MM74HC245ASJX is usually 5 days.
3.What payment methods are accepted for MM74HC245ASJX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MM74HC245ASJX transactions.
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4.How is shipping managed for MM74HC245ASJX?
MM74HC245ASJX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MM74HC245ASJX 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 MM74HC245ASJX?
For technical support, including MM74HC245ASJX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MM74HC245ASJX requirements.
6.How does Aetrix verify that MM74HC245ASJX is sourced from the original manufacturer or authorized distributors?
All MM74HC245ASJX 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 MM74HC245ASJX meets industry standards.
7.What is the process for return or replacement of MM74HC245ASJX?
All MM74HC245ASJX units undergo pre-shipment inspection (PSI). If there is an issue with MM74HC245ASJX, 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 MM74HC245ASJX part is unused and in its original packaging.
Return procedure for MM74HC245ASJX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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