SN74HCT245NG4 Texas Instruments Integrated Circuit (Dual-In-Line Packages) In Stock
Texas Instruments SN74HCT245NG4 is an octal non-inverting bus transceiver with 3-state outputs accepting 5.5 V supply in a 20-pin DIP package. It features direction control via the DIR pin and output-enable via the OE pin for bidirectional 8-bit data bus buffering. Available from stock with worldwide shipping.
- Manufacturer
- Texas Instruments
- Package
- Dual-In-Line Packages
- Pin Count
- 20
- Lifecycle
- ACTIVE
- Datasheet
- SN74HCT245NG4 Datasheet PDF
- Category
- Integrated Circuit
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- Octal bidirectional 3-state bus transceiver with non-inverting data paths and separate DIR and OE controls for flexible 8-bit bus buffering
- HCT logic family accepts TTL-compatible input thresholds (1.2 V min V_IH) while operating from a 5 V supply, enabling direct interfacing between CMOS and TTL logic families
- 20-pin DIP package supports through-hole assembly and breadboard prototyping; drives up to ±25 mA per output for bus driving across multi-load PCB environments
Applications
The SN74HCT245NG4 is used as a data bus buffer and level interface in 8-bit microprocessor systems, FPGA I/O expansion boards, and memory address/data bus isolation circuits where bidirectional data flow must be controlled between two segments of the same 5 V bus or between a 3.3 V CMOS source and a 5 V TTL load. Its through-hole DIP package is favored in prototyping environments and legacy industrial equipment where soldering through-hole components is standard practice.
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for SN74HCT245NG4:
Frequently Asked Questions
How does SN74HCT245NG4's HCT logic family enable direct interfacing between 3.3 V CMOS outputs and 5 V TTL inputs?
The HCT logic family is designed to accept TTL-compatible input thresholds: V_IH minimum is 2 V and V_IL maximum is 0.8 V. A 3.3 V CMOS output swings to approximately 3.0 V high and 0.1 V low, which both satisfy the HCT input thresholds. The SN74HCT245NG4 then drives its outputs to full 5 V CMOS levels (typically 4.9 V high, 0.1 V low) at ±25 mA, completing the level translation from 3.3 V logic to 5 V TTL-compatible bus loads without an additional level shifter IC.
For an 8-bit bidirectional data bus in a microcontroller system, how do the DIR and OE pins control data flow in SN74HCT245NG4?
DIR (direction) pin controls which side of the 8-bit transceiver is the driver: DIR = High routes data from the A port to the B port, and DIR = Low routes data from B to A. The OE (output enable) pin, when asserted Low, enables all 8 3-state outputs; when OE is High, all outputs go into high impedance, effectively disconnecting the transceiver from the bus. This allows multiple transceivers to share the same bus by time-multiplexing the OE signal, with only one device driving the bus at a time.
How does SN74HCT245NG4 compare to SN74HC245 in systems powered at 5 V with mixed TTL and CMOS logic?
SN74HC245 has CMOS input thresholds (V_IH minimum is approximately 3.15 V at 5 V supply), which means a 5 V TTL output that only swings to 2.4 V high may not reliably switch the HC part. SN74HCT245NG4's HCT thresholds (V_IH minimum 2 V) guarantee correct operation with TTL outputs. In mixed TTL/CMOS 5 V systems, SN74HCT245NG4 is the correct choice wherever legacy TTL ICs or open-collector TTL drivers feed the bus.
What output drive capability does SN74HCT245NG4 provide when buffering a heavily loaded 8-bit data bus?
Each output of SN74HCT245NG4 can source or sink up to 25 mA, allowing a single transceiver to drive up to 50 bus receivers simultaneously in a standard 74HCT family board (each HCT input draws less than 1 µA). For typical backplane applications with 10 to 20 TTL loads at 0.4 mA per input, the 25 mA output drive provides a safety margin of 60× to 6×, ensuring valid logic levels across PCB trace lengths up to 30 cm without signal conditioning.
Related Guides
CL31A107MQHNNNE 1206 100 uF MLCC Selection Guide
How to choose CL31A107MQHNNNE and related 1206 MLCCs for low-voltage bulk capacitance and regulator stability.
Jul 2, 2026
CL05B103KB5NNNC 0402 10 nF X7R MLCC Selection Guide
How to choose CL05B103KB5NNNC and related 0402 MLCCs for bypassing, filtering, voltage derating, and sourcing.
Jul 2, 2026
ADAQ7768-1 Design Guide for Precision Vibration and Dynamic Signal Measurement
Design ADAQ7768-1 precision data acquisition channels for vibration and dynamic sensing with the right bandwidth, reference, clock, and layout choices.
Jun 30, 2026
AD5204BRZ10 Design Guide for SPI-Controlled Gain and Offset Calibration
Design AD5204BRZ10 digital potentiometer calibration loops with bounded trim span, safe wiper current, clean SPI routing, and reliable startup codes.
Jun 30, 2026
Why Buy from FindMyChip
About Texas Instruments
Texas Instruments (TI) is a global semiconductor company headquartered in Dallas, Texas. TI designs and manufactures analog and embedded processing chips used in industrial, automotive, consumer, communications, and enterprise systems.
In Stock · 24h Response · Worldwide Shipping
Response within 24 hours · Worldwide shipping
“Their engineering team helped us find a pin-compatible alternative when our original MCU went EOL.”