Texas Instruments SN74CBT3253CRGYR

Overview

SN74CBT3253CRGYR from Texas Instruments is a dual 1-of-4 FET multiplexer/demultiplexer bus switch operating at 4 V–5.5 V, featuring 3 Ω typical ON-state resistance, –2 V undershoot protection on A/B ports, bidirectional signal flow, and 5.5 pF typical OFF-state I/O capacitance-used in USB interface isolation and low-distortion analog/digital signal gating.

For engineers reviewing the SN74CBT3253CRGYR datasheet, SN74CBT3253CRGYR pinout, SN74CBT3253CRGYR application, or SN74CBT3253CRGYR equivalent, this page delivers verified electrical specs, QFN-16 package layout, functional role in bus switching, and validated alternative parts for signal integrity-critical designs.

Technical Context

The SN74CBT3253CRGYR integrates two independent 1-of-4 analog switches with separate output-enable (1OE, 2OE) and dual select lines (S0, S1), enabling simultaneous or isolated channel routing. Each switch supports rail-to-rail 0–5 V signaling across all logic families including TTL, 3.3 V/5 V CMOS, and I²C-compatible buses.

Its active undershoot-protection circuitry detects sub-0 V transients up to –2 V on A/B ports and forces switch disablement to maintain off-isolation. The device implements I_off partial-power-down functionality, preventing backflow current when V_CC = 0 V while maintaining high-impedance I/O states.

Key Specifications

Pinout & Package

VQFN-16 (RGY) package: 3.0 mm × 4.0 mm body, 0.4 mm pitch, exposed thermal pad, JEDEC MO-220 compliant, moisture sensitivity level 2 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3253CRGYR, SN74CBTD3384CDWR offers greater channel density but sacrifices undershoot resilience, while PI3CH480ELEX trades dual-mux flexibility and industrial temperature range for lower voltage operation and smaller footprint.

Availability

SN74CBT3253CRGYR is available at Aetrix Electronics and suitable for USB interface isolation, I²C bus expansion, low-distortion analog gating, and legacy parallel bus isolation requiring stable component supply across industrial design cycles.

Supply support for SN74CBT3253CRGYR 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 solutions, with decades of expertise in high-speed interface ICs and industrial-grade reliability.

The SN74CBT3253CRGYR belongs to TI's CBT (Crosspoint Bus Transceiver) family, engineered specifically for low-latency, low-distortion signal routing in mixed-voltage digital and analog systems.

FAQ

What is the maximum undershoot voltage the SN74CBT3253CRGYR can withstand on its A/B ports?

The SN74CBT3253CRGYR provides active undershoot protection up to –2 V on both A and B ports when the switch is disabled. This is achieved through internal sensing circuitry that forces the FETs into a guaranteed OFF state during negative transients, preventing latch-up or damage without requiring external clamps. This specification is verified per the absolute maximum ratings table and undershoot characteristics test conditions in the official datasheet.

Does the SN74CBT3253CRGYR support partial-power-down operation, and how is it implemented?

Yes, the SN74CBT3253CRGYR supports partial-power-down via its I_off feature. When V_CC = 0 V and I/O voltages range from 0 V to 5.5 V, leakage current is limited to 10 µA maximum-preventing damaging back-current flow into unpowered domains. This behavior is intrinsic to the FET architecture and requires no external circuitry, making SN74CBT3253CRGYR suitable for systems with staggered power sequencing.

What is the typical ON-state resistance of the SN74CBT3253CRGYR, and how does it vary with voltage?

The SN74CBT3253CRGYR has a typical ON-state resistance (r_on) of 3 Ω at V_CC = 4.5 V, I_O = 30 mA, and V_I = 2.4 V. It remains stable across operating conditions: 3–6 Ω at V_CC = 4 V, and 5–10 Ω under worst-case combinations (e.g., V_I = 0 V). This low, predictable r_on ensures minimal signal attenuation and consistent impedance matching in both digital and analog signal paths.

Can the SN74CBT3253CRGYR be used with 3.3 V logic control signals while operating from a 5 V supply?

Yes, the SN74CBT3253CRGYR accepts 3.3 V logic levels on its control inputs (S0, S1, 1OE, 2OE) when powered from 5 V. Its V_IL is specified at 0.8 V max and V_IH at 2 V min, ensuring full compatibility with standard 3.3 V CMOS outputs. No level-shifting circuitry is required, simplifying interface design with modern microcontrollers and FPGAs.

What package type and thermal characteristics apply to the SN74CBT3253CRGYR?

The SN74CBT3253CRGYR uses a 16-pin VQFN package (RGY) with 3.0 mm × 4.0 mm body size, 0.4 mm pitch, and exposed thermal pad. Its thermal impedance θ_JA is 39°C/W (JEDEC JESD51-5), significantly lower than SOIC or SSOP variants-enabling higher sustained current capability and improved thermal stability in compact layouts without heatsinking.