Texas Instruments SN74CB3Q16244DL

Overview

SN74CB3Q16244DL from Texas Instruments is a 16-bit FET bus switch with four independent 4-bit channels, 5-V tolerant I/Os, 5 Ω typical ON-state resistance (ron), rail-to-rail switching (0–5 V with 3.3-V VCC), and 20 MHz maximum OE switching frequency. It enables bidirectional signal routing in high-bandwidth data paths for optical networking and wireless infrastructure equipment.

For engineers reviewing the SN74CB3Q16244DL datasheet, SN74CB3Q16244DL pinout, SN74CB3Q16244DL application, or SN74CB3Q16244DL equivalent, key selection criteria include its 48-pin SSOP package, partial-power-down support via Ioff, low 4 pF OFF-state I/O capacitance, and compatibility with 2.3–3.6-V supply rails across –40°C to 85°C operation.

Technical Context

The SN74CB3Q16244DL integrates a charge-pump circuit to elevate gate voltage of pass transistors, enabling flat, low ron (5 Ω typical) across its full 0–5-V I/O swing range. Each of its four 4-bit channels is controlled by an active-low OE input (1OE–4OE), supporting independent channel enable/disable with near-zero propagation delay (0.18 ns typical).

It features Ioff protection for partial-power-down mode, preventing backflow current when VCC = 0 V while I/Os remain at 0–5.5 V. Its control inputs accept TTL- or CMOS-level signals (VIH = 2 V min at VCC ≥ 2.7 V), and all 32 I/O pins (A/B ports) are 5-V tolerant regardless of VCC state-powered up or down.

Key Specifications

Pinout & Package

SN74CB3Q16244DL uses a 48-pin SSOP (Shrink Small Outline Package) with 15.88 mm × 7.49 mm body size, 0.635 mm lead pitch, and surface-mount gull-wing leads. Pin 1 is marked with a notch or dot; pin numbering follows standard counter-clockwise sequence from top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CB3Q16244DL, SN74CBT16244DL trades Ioff and lower capacitance for lower cost, while SN74LVC16244ADL replaces true analog switching with digital buffering-making neither a functional replacement but context-specific alternatives.

Availability

SN74CB3Q16244DL is available at Aetrix Electronics and suitable for optical networking backplanes, WiMAX baseband interfaces, and IP phone audio switching requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74CB3Q16244DL 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 company specializing in analog, embedded processing, and connectivity technologies, with decades of leadership in interface and signal-integrity solutions.

The SN74CB3Q16244DL belongs to TI's CB3Q family of high-bandwidth FET bus switches, designed specifically for low-distortion, rail-to-rail analog/digital signal routing in broadband communications and data-intensive computing systems.

FAQ

What is the maximum operating frequency supported by SN74CB3Q16244DL?

The SN74CB3Q16244DL supports a maximum OE switching frequency of 20 MHz under recommended conditions (VCC = 3.3 V, CL = 0, VO > VCC). Its high-bandwidth data path enables signal transmission up to 500 MHz, but actual usable frequency depends on PCB layout, load capacitance, and termination. The 20 MHz limit applies specifically to how fast the OE control inputs can toggle while maintaining guaranteed timing margins.

Does SN74CB3Q16244DL support partial-power-down operation?

Yes, SN74CB3Q16244DL supports partial-power-down via its Ioff feature. When VCC = 0 V, Ioff leakage is limited to 1 µA maximum while I/O pins tolerate 0–5.5 V. This prevents damaging current backflow and maintains high-impedance isolation between A and B ports, making SN74CB3Q16244DL suitable for hot-swap and multi-rail power sequencing applications.

What is the ON-state resistance (ron) specification for SN74CB3Q16244DL?

SN74CB3Q16244DL has a typical ON-state resistance (ron) of 5 Ω, measured at VI = 0 V, IO = ±30 mA, and VCC = 3.3 V. This value remains flat across the full 0–5-V I/O voltage range and operating temperature (–40°C to +85°C), ensuring consistent signal integrity and minimal propagation delay (0.18 ns typical) in both analog and digital applications.

Can SN74CB3Q16244DL interface between 3.3-V and 5-V logic domains?

Yes, SN74CB3Q16244DL supports 5-V tolerant I/Os regardless of VCC state-whether powered up (2.3–3.6 V) or powered down (VCC = 0 V). Its rail-to-rail switching allows 0–5-V signals on A/B ports with 3.3-V VCC, eliminating external level shifters in mixed-voltage systems such as FPGA-to-ASIC interconnects or legacy peripheral interfacing.

How many independent switch channels does SN74CB3Q16244DL provide?

SN74CB3Q16244DL provides four independent 4-bit switch channels (16 total bits), each controlled by a dedicated active-low output-enable pin (1OE, 2OE, 3OE, 4OE). This architecture allows flexible configuration-as four 4-bit switches, two 8-bit switches, or one 16-bit switch-enabling time-multiplexed or segmented bus routing in complex system designs.