Texas Instruments SN74CBT3244DW

Overview

SN74CBT3244DW from Texas Instruments is an octal FET bus switch organized as two independent 4-bit bidirectional low-impedance switches, featuring 5 Ω typical ON-state resistance, 6 pF typical OFF-state I/O capacitance, and sub-nanosecond propagation delay (0.25 ns typical), enabling high-speed signal routing in 5-V TTL/CMOS systems such as multi-processor interconnects and test instrumentation.

For engineers reviewing the SN74CBT3244DW datasheet, SN74CBT3244DW pinout, SN74CBT3244DW application, or SN74CBT3244DW equivalent, key selection considerations include its active-low dual OE control, 4.5 V to 5.5 V supply range, 200 MHz bandwidth capability, bidirectional zero-distortion signal path, and SOIC-20 package compatibility with standard '244 pinout layouts.

Technical Context

The SN74CBT3244DW implements eight independent analog/digital MOSFET transmission gates grouped into two 4-bit sections, each controlled by a dedicated active-low output-enable input (1OE, 2OE). Its TTL/CMOS-compatible control inputs accept 0.8 V low and 2 V high thresholds across –40°C to 85°C operation.

Each switch exhibits near-zero propagation delay due to low r_on–C_io product (5 Ω × 6 pF), supports 0–5 V data signaling levels regardless of V_CC, and draws ≤50 µA quiescent current-enabling hot-swap-capable, low-power bus isolation without directionality constraints.

Key Specifications

Pinout & Package

SN74CBT3244DW uses a 20-pin SOIC (DW) package measuring 9.97 mm × 12.60 mm with standard '244 pinout and gull-wing leads. Pin 1 is located at the index corner with notch or dot marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3244DW, SN74CBTD3384DW adds voltage translation flexibility at the cost of pinout compatibility and higher ON-resistance, while 74LVC244APW trades bidirectionality and analog transparency for ultra-low quiescent current and simpler control-but cannot replace SN74CBT3244DW in true bus-switching roles.

Availability

SN74CBT3244DW is available at Aetrix Electronics and suitable for multi-processor communications, automated test equipment, and factory automation control boards requiring stable component supply and long-term industrial lifecycle support.

Supply support for SN74CBT3244DW 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies with over 50 years of innovation in industrial-grade IC design and manufacturing.

The SN74CBT3244DW belongs to TI's CBT (Crosspoint Bus Transceiver) family, engineered specifically for high-bandwidth, low-latency digital bus switching in industrial control, instrumentation, and computing infrastructure where signal integrity and pin compatibility are critical.

FAQ

What is the maximum operating frequency supported by the SN74CBT3244DW?

The SN74CBT3244DW supports signal switching up to 200 MHz, enabled by its 5 Ω typical ON-state resistance and 6 pF typical OFF-state I/O capacitance. This bandwidth is achievable under recommended conditions: 5 V supply, 50 pF load, and proper PCB layout with minimized trace inductance and capacitance. The device's 0.25 ns typical propagation delay ensures minimal timing skew across all eight channels in the SN74CBT3244DW.

Does the SN74CBT3244DW support bidirectional signal flow without external direction control?

Yes, the SN74CBT3244DW provides fully bidirectional signal flow between A and B ports within each 4-bit group-no direction pin or control logic is needed. When 1OE or 2OE is driven low, the corresponding A↔B path conducts equally in either direction, making the SN74CBT3244DW ideal for bus isolation, hot-swap applications, and dynamic bus sharing where signal polarity or source/sink role may change.

Can the SN74CBT3244DW operate with mixed-voltage I/O signals (e.g., 3.3 V MCU to 5 V peripheral)?

Yes, the SN74CBT3244DW supports 0–5 V signaling levels on all I/O pins regardless of V_CC (4.5–5.5 V), allowing direct interface between 3.3 V, 2.5 V, or 1.8 V logic and 5 V systems. This voltage-agnostic behavior is inherent to its FET switch architecture and does not require external level shifters-making the SN74CBT3244DW especially valuable in heterogeneous voltage domain designs.

What is the recommended power supply decoupling for the SN74CBT3244DW?

Texas Instruments specifies a 0.1 µF ceramic bypass capacitor placed as close as possible between pin 20 (V_CC) and pin 10 (GND) for the SN74CBT3244DW. This placement minimizes high-frequency supply noise and prevents switching transients from coupling into adjacent traces. No additional bulk capacitance is required unless the board-level power distribution network exhibits excessive impedance above 10 MHz.

Is the SN74CBT3244DW pin-compatible with legacy 74-series '244 devices?

Yes, the SN74CBT3244DW uses the industry-standard '244 pinout across its SOIC-20 (DW) package, matching pin-for-pin with 74LS244, 74ALS244, and other '244-family buffers. However, unlike those TTL buffers, the SN74CBT3244DW is a bidirectional analog switch-not a 3-state digital buffer-so it replaces them functionally only in bus-switching roles, not in unidirectional driving applications.