Texas Instruments SN74CBT3244DGVR

Overview

SN74CBT3244DGVR 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-compatible digital systems such as multi-processor interconnects and automated test equipment.

For engineers reviewing the SN74CBT3244DGVR datasheet, SN74CBT3244DGVR pinout, SN74CBT3244DGVR application, or SN74CBT3244DGVR equivalent, key selection criteria include its active-low dual OE control architecture, 0–5 V data-level tolerance across all I/Os, 4.5–5.5 V supply range, and TVSOP-20 package compatibility with space-constrained industrial PCB layouts.

Technical Context

The SN74CBT3244DGVR implements eight independent analog/digital MOSFET transmission gates grouped into two 4-bit channels, 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 at 5 V supply, supporting direct interfacing with legacy microcontrollers and FPGA I/O banks.

Each channel operates bidirectionally with near-zero propagation delay due to flat, low on-resistance (5 Ω typical) and minimal parasitic capacitance (6 pF typical), preserving signal integrity up to 200 MHz. The device requires no level-shifting circuitry for mixed-voltage signaling between 0 V, 1.2 V, 1.5 V, 1.8 V, 2.5 V, 3.3 V, and 5 V logic domains.

Key Specifications

Pinout & Package

SN74CBT3244DGVR is housed in a 20-pin Thin Very Small Outline Package (TVSOP), measuring 5.85 mm × 4.35 mm with 0.65 mm lead pitch and 1.2 mm max height. This thermally enhanced, surface-mount package supports fine-pitch PCB assembly and provides improved thermal resistance (RθJA = 92 °C/W) versus SOIC alternatives.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3244DGVR, SN74CBTD3384PWR offers greater channel count but sacrifices 5-V compatibility and adds layout overhead for unused bits, while 74LVC244APW reduces cost and power but eliminates bidirectional flexibility and mixed-voltage operation essential for legacy interface bridging.

Availability

SN74CBT3244DGVR is available at Aetrix Electronics and suitable for multi-processor communications, automated test equipment, and factory automation control boards requiring stable component supply across extended product lifecycles.

Supply support for SN74CBT3244DGVR 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 high-reliability industrial and automotive ICs.

The SN74CBT3244DGVR belongs to TI's CBT (Crosspoint Bus Transceiver) family, engineered specifically for high-bandwidth, low-latency digital signal routing in industrial control, test instrumentation, and communication infrastructure.

FAQ

What is the function of the 1OE and 2OE pins on the SN74CBT3244DGVR?

The 1OE and 2OE pins are active-low output-enable controls for the two independent 4-bit switch groups. When pulled low, each enables bidirectional conduction between its associated A and B port pairs (e.g., 1OE low connects 1A1–1A4 ↔ 1B1–1B4). When high, both sides enter high-impedance isolation. Proper pull-up to VCC is recommended during power-up to prevent undefined states. This behavior is confirmed in the SN74CBT3244DGVR functional mode table and pin description section.

Does the SN74CBT3244DGVR support mixed-voltage signaling between 3.3 V and 5 V domains?

Yes, the SN74CBT3244DGVR supports 0–5 V signaling on all I/O pins regardless of VCC setting (4.5–5.5 V), enabling direct connection between 3.3 V FPGA I/Os and 5 V microcontroller buses without external level shifters. This capability is explicitly stated in the "Data I/Os Support 0- to 5-V Signaling Levels" feature and verified in Electrical Characteristics tables under VI and VO ratings.

What is the maximum frequency supported by the SN74CBT3244DGVR in practical PCB layouts?

The SN74CBT3244DGVR is characterized for up to 200 MHz operation under ideal conditions, based on its 0.25 ns typical propagation delay and low 5 Ω ron / 6 pF Cio combination. Real-world performance depends on trace impedance, length, and load capacitance; layout guidelines recommend minimizing stubs and using controlled-impedance routing to maintain signal integrity above 100 MHz. This is documented in the Feature Description and Layout sections of the SN74CBT3244DGVR datasheet.

Is a bypass capacitor required for the SN74CBT3244DGVR, and if so, what value and placement is recommended?

Yes, a 0.1 µF ceramic bypass capacitor is required between VCC and GND, placed as close as possible to the SN74CBT3244DGVR's power pins. This mitigates supply noise and prevents transient-induced switching errors, especially during high-frequency toggling. The recommendation is specified in Section 9.2.1 (Design Requirements) and Section 10 (Power Supply Recommendations) of the SN74CBT3244DGVR datasheet.

What is the thermal resistance (RθJA) of the SN74CBT3244DGVR in its TVSOP package?

The SN74CBT3244DGVR in the TVSOP (DGV) package has a junction-to-ambient thermal resistance (RθJA) of 92 °C/W, as published in the Thermal Information table of the datasheet. This value assumes standard JEDEC 2-layer board conditions and confirms suitability for industrial ambient temperatures up to +85 °C without forced cooling, provided power dissipation remains within ICC-limited bounds.