onsemi MC74VHCT374ADTR2

Overview

MC74VHCT374ADTR2 from onsemi is an octal D-type transparent latch with 3-state outputs, designed for bus-oriented applications requiring high-speed, low-power CMOS logic compatible with TTL input levels. It operates at 4.5–5.5 V, features 7.5 ns propagation delay (max), 4 µA quiescent current (max), and supports 8-bit data latching with independent output enable control.

For engineers reviewing the MC74VHCT374ADTR2 datasheet, pinout, applications, or equivalent options, key selection criteria include TTL-compatible input thresholds, 3-state bus driving capability, industrial temperature range (−40°C to +85°C), and TSSOP-20 package suitability for high-density PCB layouts.

Technical Context

This device implements eight edge-triggered D-type flip-flops with common clock and output enable, configured as a transparent latch during clock high. Its VHCT logic family ensures TTL-level input compatibility while maintaining CMOS power efficiency and noise immunity.

The 3-state outputs are controlled by an active-low OE pin, enabling bidirectional bus sharing without external gating. Propagation delay is specified at V_CC = 5.0 V, T_A = 25°C, and C_L = 50 pF, with guaranteed performance across the full industrial temperature range.

Key Specifications

Pinout & Package

TSSOP-20 surface-mount package with 0.65 mm pitch, 6.5 mm × 4.4 mm body, and exposed thermal pad (non-electrical). RoHS-compliant, lead-free finish.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal transparent latch applications.

Compared with SN74HCT374PWR and 74VHC374M, the MC74VHCT374ADTR2 uniquely balances TTL input compatibility, 7.5 ns speed, and industrial temperature range-making it optimal for mixed-signal industrial controllers where legacy interface support and timing precision are both essential.

Availability

MC74VHCT374ADTR2 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, automotive body control modules, and test equipment data capture requiring stable component supply and long-term lifecycle assurance.

Supply support for MC74VHCT374ADTR2 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 MC74VHCT374ADTR2 belongs to the VHCT logic family, engineered specifically for TTL-to-CMOS bridging in high-reliability industrial and automotive control systems where input compatibility and timing predictability are critical.

FAQ

What is the maximum clock frequency supported by MC74VHCT374ADTR2?

The MC74VHCT374ADTR2 does not specify a maximum clock frequency in its datasheet; instead, it guarantees timing performance via propagation delay (7.5 ns max) and setup/hold times (3.0 ns min setup, 3.0 ns min hold). For reliable operation, designers should ensure clock period exceeds t_PD + t_su + t_h, supporting practical frequencies up to 80–100 MHz in well-decoupled 5 V systems. The MC74VHCT374ADTR2 is optimized for synchronous bus latching-not continuous high-frequency toggling.

Does MC74VHCT374ADTR2 support hot insertion or live bus swapping?

No, the MC74VHCT374ADTR2 is not rated for hot insertion. Its absolute maximum ratings do not include powered-insertion stress conditions, and the TSSOP-20 package lacks built-in bus-hold or power-up/down protection circuitry. To implement live bus swapping, external series resistors and TVS diodes must be added per I/O line. The MC74VHCT374ADTR2 requires stable V_CC and GND before applying signals to any pin.

Can MC74VHCT374ADTR2 operate at 3.3 V supply?

No, the MC74VHCT374ADTR2 is specified only for 4.5 V to 5.5 V operation. At 3.3 V, input thresholds (V_IL/V_IH) fall outside TTL-compatibility range, and output drive strength degrades significantly below specification. Using 3.3 V violates the Absolute Maximum Ratings and may cause unreliable latching or increased static current. For 3.3 V systems, consider the MC74VHC374ADTR2 instead.

What is the purpose of the OE pin on MC74VHCT374ADTR2?

The OE (Output Enable) pin on the MC74VHCT374ADTR2 is an active-low control that places all eight Q outputs in high-impedance state when asserted HIGH. When OE is LOW, outputs reflect the latched or transparent data based on CLK state. This enables bidirectional bus sharing, prevents contention during MCU reset, and allows multiple devices to share a common data bus-critical in industrial backplane and automotive domain controller designs using the MC74VHCT374ADTR2.

Is MC74VHCT374ADTR2 pin-compatible with standard 74LS374?

Yes, the MC74VHCT374ADTR2 is pin-compatible with the 74LS374 in TSSOP-20 and SOIC-20 packages, sharing identical pin assignments for D, Q, CLK, OE, V_CC, and GND. However, it is not a direct functional drop-in replacement due to differences in output drive strength (8 mA vs. 16 mA for LS), propagation delay (7.5 ns vs. 25 ns), and quiescent current (4 µA vs. 20 mA). System validation is required when substituting MC74VHCT374ADTR2 for 74LS374.