My Inquiry
My Account
NXP Semiconductors 74AHCT245D,118
- Part No.:
- 74AHCT245D,118
- Manufacturer:
- NXP Semiconductors
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
74AHCT245D,118.pdf
- Description:
- IC TXRX NON-INVERT 5.5V 20SO
- Quantity:
- Payment:
- Shipping:
Inventory:5,665
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
74AHCT245D,118 from Nexperia is an octal 3-state bus transceiver with TTL-compatible input thresholds, direction control (DIR), and active-low output enable (OE). It operates from 4.5 V to 5.5 V, supports bidirectional data flow between A- and B-buses, features overvoltage-tolerant inputs up to 5.5 V, and is rated for -40 °C to +125 °C operation in SO20 package. It enables voltage-level translation and bus isolation in industrial microcontroller interfaces.
For engineers reviewing the 74AHCT245D,118 datasheet, 74AHCT245D,118 pinout, 74AHCT245D,118 application, or 74AHCT245D,118 equivalent, key selection criteria include TTL-level input compatibility, 3-state output timing (tpd ≤ 7.7 ns at 5 V/15 pF), SO20 thermal derating above 109 °C, and directional bus control logic in mixed-voltage systems.
Technical Context
The 74AHCT245D,118 implements a dual-rail bidirectional bus interface with independent DIR and OE control signals. Its TTL-compatible inputs (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 4.5–5.5 V) ensure reliable interfacing with legacy 5 V logic families, while overvoltage tolerance (up to 5.5 V) allows safe operation when A- or B-side buses float or exceed VCC.
Propagation delay is asymmetrically optimized: tpd from A-to-B or B-to-A is ≤ 7.7 ns (typical 4.5 ns) at VCC = 5 V and CL = 15 pF; enable/disable times (ten/tdis) are ≤ 13.8 ns and ≤ 15.4 ns respectively under same conditions. The device uses standard CMOS output stages with rail-to-rail VOH/VOL and Schmitt-trigger inputs for noise immunity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5 V to 5.5 V - ensures compatibility with standard 5 V TTL and CMOS systems without level-shifting circuitry. |
| Input Thresholds | VIH = 2.0 V min, VIL = 0.8 V max - matches TTL logic levels for direct connection to 74LS/74F families. |
| Propagation Delay | ≤ 7.7 ns (CL = 15 pF, VCC = 5 V) - enables high-speed bidirectional data transfer in 20–25 MHz bus applications. |
| Output Drive | ±8 mA (VOH/VOL guaranteed at 5 V) - sufficient to drive 10 LSTTL loads or 15 pF PCB traces without buffering. |
| Operating Temperature | -40 °C to +125 °C - qualified for under-hood automotive modules, industrial PLC backplanes, and extended-range embedded controllers. |
| Input Overvoltage Tolerance | Up to 5.5 V regardless of VCC - permits safe hot-plug operation and mixed-supply bus arbitration without external clamping diodes. |
| Power Dissipation | 500 mW max (SO20, Tamb ≤ 109 °C); derates 12.3 mW/K above - defines thermal limits for continuous operation in enclosed enclosures. |
Pinout & Package
74AHCT245D,118 is supplied in SO20 (SOT163-1) plastic small outline package: 20-pin, 7.5 mm body width, 1.27 mm pitch, gull-wing leads. Thermal pad is not present; JEDEC MS-013 compliant footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (DIR) | Direction control input | LOW routes data from A-side to B-side; HIGH routes from B-side to A-side - enables full-duplex bus arbitration in master/slave configurations. |
| 2–9 (A0–A7) | Port A data I/O | Bi-directional terminals tied to local controller or microprocessor data bus - require no external pull-ups when used as outputs in 3-state mode. |
| 10 (GND) | Ground reference | 0 V return path for all internal logic and output drivers - must be low-inductance connected to system ground plane. |
| 11–18 (B0–B7) | Port B data I/O | Bi-directional terminals connected to peripheral bus or memory subsystem - electrically isolated from A-side when OE is HIGH. |
| 19 (OE) | Output enable (active LOW) | Drives all A/B outputs to high-impedance when HIGH - used for bus contention avoidance during multi-master arbitration. |
| 20 (VCC) | Supply voltage | +4.5 V to +5.5 V power rail - requires local 100 nF ceramic decoupling placed within 5 mm of pin 20. |
Key Features
| Feature | Design Value |
|---|---|
| TTL-compatible inputs | VIH = 2.0 V min / VIL = 0.8 V max at 5 V - eliminates need for external level translators when interfacing with 74LS, 74F, or older microcontrollers. |
| Overvoltage-tolerant I/O | Withstands 5.5 V on any input or output regardless of VCC - enables safe use in hot-swap backplanes and mixed-voltage board designs. |
| Schmitt-trigger inputs | Hysteresis ≥ 0.3 V typical - rejects noise on slow-rising or long-trace control lines (DIR/OE), preventing metastability in noisy industrial environments. |
| Low dynamic power | CPD = 15 pF - reduces switching current consumption in high-frequency bus toggling (e.g., 10 MHz address/data bursts). |
| Extended temperature range | Specified from -40 °C to +125 °C - supports deployment in engine control units, motor drives, and outdoor telecom equipment without derating. |
Applications
| Industrial PLC Backplane Interface | Microcontroller Peripheral Expansion |
|---|---|
Use Scenario: Isolating CPU data bus from modular I/O cards in a programmable logic controller rack with shared backplane wiring. IC Role / Device Role / Timing Role: Bidirectional bus transceiver managing data flow between ARM Cortex-M7 host and isolated CAN/RS-485 slave modules via DIR-controlled A↔B paths. Use Value: Prevents bus contention during card insertion/removal; 3-state outputs allow multiple transceivers to share one backplane segment without hardware arbitration logic. | Use Scenario: Expanding GPIO count of an STM32F407 MCU by connecting parallel LCD controller and SD card interface to separate 8-bit data ports. IC Role / Device Role / Timing Role: Direction-controlled data bridge enabling simultaneous read/write operations: DIR = LOW for LCD write, DIR = HIGH for SD read, OE synchronized to peripheral chip selects. Use Value: Eliminates need for discrete MOSFET switches or CPLD glue logic; propagation delay <8 ns ensures timing compliance with 20 MHz LCD pixel clocks and 25 MHz SD data rates. |
| Legacy System Voltage Translation | Test Equipment Bus Arbitration |
Use Scenario: Interfacing a modern 3.3 V FPGA I/O bank to legacy 5 V TTL test instrumentation (e.g., logic analyzers, pattern generators) without level-shifter ICs. IC Role / Device Role / Timing Role: Level-translating transceiver operating at VCC = 5 V, accepting 3.3 V logic on A-side (overvoltage tolerant) and driving 5 V outputs on B-side. Use Value: Enables direct connection to 5 V test gear using only passive decoupling; VIH/VIL thresholds guarantee noise-immune recognition of FPGA output swings. | Use Scenario: Managing shared JTAG/SWD debug bus among multiple SoCs on a production test fixture where only one device may drive the bus at a time. IC Role / Device Role / Timing Role: 3-state bus isolator controlled by test sequencer - OE asserts per-device to prevent signal collisions during boundary-scan chain configuration. Use Value: Reduces fixture complexity by replacing mechanical relays or analog switches; fast disable time (<15.5 ns) ensures glitch-free bus handoff between DUTs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal bus transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LVC245APWR | CMOS input thresholds (VIH = 2.0 V @ 3.3 V), 1.65–3.6 V supply, lower drive (±24 mA), 32 mA ICC max | Optimized for 3.3 V systems; lacks TTL compatibility and 5 V overvoltage tolerance | Select when interfacing exclusively with 3.3 V LVTTL/LVCMOS devices and space-constrained PCBs (TSSOP20). |
| 74AHC245D,118 | CMOS input thresholds (VIH = 3.85 V @ 5.5 V), 2.0–5.5 V supply, same SO20 package, identical pinout | Requires 3.3 V or 5 V logic sources; unsuitable for direct 74LS interface without pull-up resistors | Select when mixing 3.3 V and 5 V domains with CMOS logic families and needing higher noise margin than TTL. |
Compared with SN74LVC245APWR and 74AHC245D,118, the 74AHCT245D,118 uniquely supports legacy 5 V TTL signaling without external biasing while maintaining robust overvoltage tolerance-making it the only choice for retrofitting 74LS-based systems with modern microcontrollers.
Availability
74AHCT245D,118 is available at Aetrix Electronics and suitable for industrial PLC backplanes, microcontroller peripheral expansion, legacy system voltage translation, and test equipment bus arbitration requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for 74AHCT245D,118 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
Nexperia is a global semiconductor expert focused on essential efficiency technologies, delivering high-performance logic, analog, and MOSFET solutions for automotive, industrial, and consumer markets.
The 74AHCT245D,118 belongs to Nexperia's industry-standard 74-series logic family, designed specifically for robust, drop-in replacement of legacy TTL transceivers in mixed-voltage embedded systems requiring extended temperature operation and noise immunity.
FAQ
What is the maximum clock/data rate supported by 74AHCT245D,118?
The 74AHCT245D,118 does not operate on a clock; it is asynchronous. Its usable data rate depends on propagation delay and bus loading. With tpd ≤ 7.7 ns (VCC = 5 V, CL = 15 pF), it supports reliable bidirectional transfers up to ~25 MHz in well-terminated 8-bit buses. For sustained 50% duty-cycle toggling, limit frequency to ≤ 20 MHz to maintain setup/hold margins.
Can 74AHCT245D,118 interface between 3.3 V and 5 V buses?
Yes - its inputs tolerate up to 5.5 V regardless of VCC, allowing 3.3 V devices to drive the A-side while VCC = 5 V powers B-side outputs. However, outputs swing rail-to-rail: A-side outputs will be 0–5 V, so receiving 3.3 V logic must be overvoltage-tolerant or buffered. Direct 3.3 V receiver connection is safe only if the receiver accepts 5 V inputs.
Is the SO20 package lead-free and RoHS-compliant?
Yes - the 74AHCT245D,118 in SO20 (SOT163-1) package is manufactured per Nexperia's standard RoHS-compliant process, with lead-free matte tin terminations and halogen-free molding compound. It meets EU Directive 2011/65/EU and is rated for SnPb reflow profiles (JEDEC J-STD-020D) and lead-free soldering (260 °C peak).
How does DIR and OE interact during bus switching?
OE is prioritized: when OE = HIGH, all outputs go high-impedance regardless of DIR state. When OE = LOW, DIR determines direction - DIR = LOW enables A→B flow; DIR = HIGH enables B→A flow. This allows safe bus handoff: assert OE first to tri-state, change DIR, then de-assert OE to engage new direction - eliminating bus glitches.
74AHCT245D,118 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- 74AHCT
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Bulk
- Product Status:
- Active
- 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:
- 8mA, 8mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SO
74AHCT245D,118 FAQ
1.How can I place an order for 74AHCT245D,118 through Aetrix?
Please submit a Request for Quotation (RFQ) for 74AHCT245D,118 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 74AHCT245D,118 reliable?
The price and inventory of 74AHCT245D,118 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74AHCT245D,118 is usually 5 days.
3.What payment methods are accepted for 74AHCT245D,118?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74AHCT245D,118 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74AHCT245D,118?
74AHCT245D,118 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74AHCT245D,118 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 74AHCT245D,118?
For technical support, including 74AHCT245D,118 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74AHCT245D,118 requirements.
6.How does Aetrix verify that 74AHCT245D,118 is sourced from the original manufacturer or authorized distributors?
All 74AHCT245D,118 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 74AHCT245D,118 meets industry standards.
7.What is the process for return or replacement of 74AHCT245D,118?
All 74AHCT245D,118 units undergo pre-shipment inspection (PSI). If there is an issue with 74AHCT245D,118, 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 74AHCT245D,118 part is unused and in its original packaging.
Return procedure for 74AHCT245D,118:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
74AHCT245D,118 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…
