onsemi MC74VHCT245AMELG

Overview

MC74VHCT245AMELG from onsemi is an octal bus transceiver with 3-state outputs, designed for bidirectional data transmission between two 8-bit buses in mixed-voltage systems. It operates at 4.5–5.5 V supply, supports 8 mA output drive, features TTL-compatible inputs, and is rated for industrial temperature range (−40°C to +85°C). It is commonly used in microcontroller peripheral interfacing and memory address/data bus isolation.

For engineers reviewing the MC74VHCT245AMELG datasheet, pinout, applications, or equivalent options, key selection criteria include its 5 V supply tolerance, bidirectional flow control via DIR and OE pins, 3-state output capability, and compatibility with both TTL and CMOS logic families in level-shifting applications.

Technical Context

The MC74VHCT245AMELG implements dual-rail 3-state bus transceivers with independent direction (DIR) and output-enable (OE) controls per device. Its input thresholds are TTL-compatible (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V), while output swing is rail-to-rail under 5 V supply. Propagation delay is specified at 4.5 ns (max) at V_CC = 5 V, enabling use in high-speed digital interconnects up to 100 MHz clock domains.

It uses advanced silicon-gate CMOS technology to achieve low static power consumption (< 4 µA typical I_CC) while maintaining robust noise immunity (V_NL ≥ 0.5 V, V_NH ≥ 0.5 V). The device is not designed for hot-swap or live-insertion; all control and data signals must be stable before V_CC ramp-up.

Key Specifications

Pinout & Package

MC74VHCT245AMELG is housed in a 20-pin SOIC (Small Outline Integrated Circuit) package with 0.300-inch body width and standard 1.27 mm pitch. Pin numbering follows JEDEC MS-013, with pin 1 marked by a notch or dot.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus transceiver applications.

Compared with SN74HCT245N and 74VHC245M, the MC74VHCT245AMELG delivers optimal balance of TTL compatibility, low quiescent current, and tight propagation delay - making it preferred for industrial microcontroller interfaces where signal integrity and power efficiency are jointly constrained.

Availability

MC74VHCT245AMELG is available at Aetrix Electronics and suitable for industrial control systems, embedded instrumentation, and legacy bus interface designs requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MC74VHCT245AMELG 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 is a global semiconductor leader delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The MC74VHCT245AMELG belongs to onsemi's VHCT logic family, engineered specifically for high-speed, low-power 5 V digital interfacing in industrial and embedded systems where TTL compatibility and timing precision are essential.

FAQ

What is the maximum clock frequency supported by MC74VHCT245AMELG?

The MC74VHCT245AMELG does not operate on a clock signal-it is an asynchronous bus transceiver. Its usable data rate depends on propagation delay (4.5 ns max) and system timing margins. In practice, it reliably supports bidirectional data transfers up to 100 MHz in well-designed PCB layouts with controlled impedance and proper termination.

Does MC74VHCT245AMELG support hot-plug or live insertion?

No, MC74VHCT245AMELG is not designed for hot-plug operation. All control signals (DIR, OE) and supply voltage must be stable before data is applied. Applying inputs before V_CC reaches 4.5 V may cause latch-up or undefined output states. Power sequencing per onsemi's recommended guidelines is mandatory.

Can MC74VHCT245AMELG interface directly with 3.3 V logic devices?

MC74VHCT245AMELG inputs are TTL-compatible and accept 3.3 V logic-high signals safely (V_IH ≥ 2.0 V), but its outputs swing rail-to-rail at 5 V. Direct connection to 3.3 V-only inputs risks overvoltage damage unless the receiving device specifies 5 V-tolerant inputs. External level-shifting or series resistors are required for safe 3.3 V receiver interfacing.

What is the function of the DIR pin on MC74VHCT245AMELG?

The DIR (Direction) pin on MC74VHCT245AMELG controls data flow direction: logic low enables transmission from Port A to Port B; logic high enables transmission from Port B to Port A. It operates independently of OE and remains effective only when OE is asserted (low). This allows flexible bidirectional bus arbitration in shared-memory architectures.

Is MC74VHCT245AMELG RoHS compliant and lead-free?

Yes, MC74VHCT245AMELG is RoHS compliant and lead-free. It meets EU Directive 2011/65/EU and is manufactured using onsemi's standard green packaging process. The "G" suffix in the part number explicitly denotes lead-free, halogen-free, and RoHS-compliant construction per onsemi's packaging nomenclature.