onsemi MC74ACT652DWR2G

Overview

MC74ACT652DWR2G from onsemi is an octal registered bus transceiver with 3-state outputs and non-inverting logic, designed for bidirectional data flow control between A and B buses in high-speed digital systems. It features independent A/B registers, real-time and stored-data multiplexing, TTL-compatible inputs, ±24 mA output drive, and operates at 4.5–5.5 V supply. It is used in address/data bus isolation and register-controlled data routing in industrial controllers and communication interface modules.

For engineers reviewing the MC74ACT652DWR2G datasheet, pinout, applications, or equivalent options, key selection considerations include clock-controlled register loading (CAB/CBA), dual-direction transmit/receive control (SAB/SBA), 3-state output enable (GAB/GBA), and SOIC-24 package compatibility with legacy 300-mil DIP footprints.

Technical Context

The MC74ACT652DWR2G implements two independent 8-bit D-type flip-flop registers synchronized to separate LOW-to-HIGH clock edges on CAB (load A bus → A register) and CBA (load B bus → B register). Its logic supports four concurrent data-handling modes: real-time A→B or B→A transfer, storage from either bus to both registers, and simultaneous stored-data bidirectional exchange.

Control is managed via three signal groups per direction: SAB/SBA select real-time vs. registered data path; GAB/GBA enable/disable A→B or B→A 3-state outputs; and CAB/CBA trigger register updates. All inputs are TTL-compatible, and outputs meet ±24 mA drive strength at V_CC = 5.0 V with guaranteed VOL ≤ 0.44 V and VOH ≥ 4.76 V under load.

Key Specifications

Pinout & Package

MC74ACT652DWR2G is housed in a 24-pin SOIC (Small Outline Integrated Circuit) package, case 751E, with 300-mil body width and 1.27 mm lead pitch. The package is Pb-free and RoHS-compliant, rated MSL Level 1, and supports standard IR reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ACT652N and 74LVTH16652DGGR, the MC74ACT652DWR2G provides drop-in SOIC-24 compatibility with industrial temperature support and Pb-free compliance - making it optimal for volume SMT production where reliability, regulatory alignment, and footprint reuse are critical.

Availability

MC74ACT652DWR2G is available at Aetrix Electronics and suitable for industrial PLC backplanes, legacy microcontroller bus expansion, and modular communication hubs requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for MC74ACT652DWR2G 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 (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient silicon solutions for automotive, industrial, cloud, and IoT applications.

The MC74ACT652DWR2G belongs to the 74ACT advanced CMOS logic family, engineered for high-speed, low-noise bidirectional bus interfacing in industrial control and instrumentation systems where TTL compatibility and robust 3-state control are essential.

FAQ

What is the maximum clock frequency supported by MC74ACT652DWR2G?

The MC74ACT652DWR2G does not specify a maximum clock frequency in its datasheet; instead, timing is defined by minimum pulse width (t_w = 6.0 ns for CAB/CBA at V_CC = 5.0 V) and setup/hold requirements (t_su = 8.0 ns, t_h = 2.5 ns). These values support reliable operation up to approximately 80 MHz in well-designed layouts with controlled trace impedance and proper decoupling - always validate timing margins using worst-case AC parameters from the official datasheet.

Can MC74ACT652DWR2G operate at 3.3 V supply?

No, MC74ACT652DWR2G is not rated for 3.3 V operation. Its recommended V_CC range is strictly 4.5–5.5 V, and DC characteristics (e.g., VIH = 2.0 V min) are only guaranteed within that range. Attempting 3.3 V operation risks undefined logic states, reduced noise margin, and failure to meet output drive specifications - use 74LVT or 74ALVC series devices for true 3.3 V compatibility.

Does MC74ACT652DWR2G support simultaneous A→B and B→A data transfer?

No, MC74ACT652DWR2G does not support true simultaneous bidirectional transfer. Its function table shows that when GAB and GBA are both low, stored-A data appears on B-bus *and* stored-B data appears on A-bus - but this occurs in a single cycle only when SAB = SBA = H and clocks are aligned. Real-time transfer in both directions concurrently is not supported; the device operates in directional mode per control signal combination.

What is the thermal resistance (θ_JA) of MC74ACT652DWR2G in SOIC-24 package?

The MC74ACT652DWR2G has a junction-to-ambient thermal resistance (θ_JA) of 59.8°C/W, measured per JESD51-7 on a standard JEDEC 2-layer test board. This value assumes no added copper pour or thermal vias; actual board-level θ_JA will improve with enhanced PCB copper area and thermal relief design - critical for sustained 24 mA output loading across all 16 I/O pins.

Is MC74ACT652DWR2G pin-compatible with MC74AC652DWR2G?

Yes, MC74ACT652DWR2G is pin-compatible and functionally interchangeable with MC74AC652DWR2G in the same SOIC-24 package. Both share identical pinout, register architecture, and 3-state control logic. The key difference is input threshold: MC74ACT652DWR2G has TTL-compatible inputs (VIH = 2.0 V), while MC74AC652DWR2G uses CMOS thresholds (VIH = 3.15 V at 4.5 V), making ACT version preferable for mixed-logic-level systems.