Texas Instruments SN74CBT3253CDRG4

Overview

SN74CBT3253CDRG4 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. It enables low-distortion USB interface and bus isolation in mixed-voltage digital systems.

For engineers reviewing the SN74CBT3253CDRG4 datasheet, SN74CBT3253CDRG4 pinout, SN74CBT3253CDRG4 application, or SN74CBT3253CDRG4 equivalent, this page delivers verified electrical parameters, SOIC-16 package mapping, functional pin roles, real-world use cases for I²C expansion and analog signal gating, and two validated alternative parts with documented technical differences.

Technical Context

The SN74CBT3253CDRG4 implements two independent 1-of-4 FET switches controlled by S0/S1 select lines and dedicated OE inputs (1OE, 2OE), enabling simultaneous or isolated channel routing. Its active undershoot-protection circuitry clamps A/B port transients to –2 V while maintaining high-impedance isolation during power-down.

Each switch supports 0–5 V signaling across logic families (TTL, 3.3 V/5 V CMOS), with I_off limiting backflow current when V_CC = 0 V. Propagation delay is near-zero (0.24 ns typical at V_CC = 5 V), and input/output capacitance is minimized (5.5 pF OFF, 22 pF ON) to preserve signal integrity in high-speed digital and analog paths.

Key Specifications

Pinout & Package

SN74CBT3253CDRG4 is packaged in a 16-pin SOIC (D) body measuring 9.9 mm × 3.91 mm × 1.45 mm (JEDEC MS-012), with gull-wing leads, NIPDAU finish, and moisture sensitivity level 1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar FET multiplexer/demultiplexer applications.

Compared with SN74CBT3253CDRG4, SN74CBTD3384CDW offers greater channel count but sacrifices undershoot resilience and low r_on, while 74LVC1G3157GW reduces footprint at the cost of architectural flexibility and industrial reliability - making SN74CBT3253CDRG4 optimal for dual-bank, mixed-voltage, noise-prone applications.

Availability

SN74CBT3253CDRG4 is available at Aetrix Electronics and suitable for USB interface isolation, I²C bus expansion, low-distortion analog signal gating, and legacy bus voltage translation requiring stable component supply across industrial design cycles.

Supply support for SN74CBT3253CDRG4 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 90 years of innovation in high-reliability components.

The SN74CBT3253CDRG4 belongs to TI's CBT (Crosspoint Bus Transceiver) family, engineered for high-speed, low-distortion signal routing in mixed-voltage digital and analog systems - particularly targeting interface consolidation and bus robustness in industrial and communications equipment.

FAQ

What is the maximum undershoot voltage the SN74CBT3253CDRG4 can safely withstand?

The SN74CBT3253CDRG4 provides active undershoot protection up to –2 V on both A and B ports when disabled, as confirmed in the Absolute Maximum Ratings and Undershoot Characteristics tables. This capability eliminates the need for external clamping diodes in USB, hot-swap, or noisy industrial environments. The protection circuit senses the event and maintains proper OFF-state isolation. Exceeding –2 V risks damage or unpredictable behavior, so system-level transient suppression remains advisable for extreme conditions.

Does the SN74CBT3253CDRG4 support 3.3-V-only logic control inputs?

Yes, the SN74CBT3253CDRG4 accepts TTL and 5-V/3.3-V CMOS-compatible control inputs (S0, S1, 1OE, 2OE). Its V_IL is specified at 0.8 V max and V_IH at 2 V min over the full temperature range, ensuring reliable recognition of 3.3-V logic highs and lows even with margin. No level-shifting circuitry is required, simplifying interface design with modern low-voltage microcontrollers while maintaining full 0–5 V data I/O compatibility.

Can the SN74CBT3253CDRG4 be used for analog signal switching?

Yes, the SN74CBT3253CDRG4 is qualified for analog applications due to its low 3 Ω typical r_on, flat r_on vs. voltage profile, and minimal charge injection (<1 pC). It supports 0–5 V analog signals (e.g., sensor outputs, audio paths) with negligible gain error and distortion. The 5.5 pF C_io(OFF) ensures low crosstalk, and the absence of body diode conduction preserves signal polarity - making SN74CBT3253CDRG4 suitable for precision 12-bit measurement and audio gating where passive switches fall short.

What is the thermal performance of the SN74CBT3253CDRG4 in SOIC-16 package?

The SN74CBT3253CDRG4 in SOIC-16 (D package) has a junction-to-ambient thermal resistance (θ_JA) of 73°C/W, as specified in the Absolute Maximum Ratings table. At maximum rated continuous current (±128 mA) and worst-case r_on (6 Ω), power dissipation remains below 100 mW, resulting in a junction temperature rise of <7.3°C above ambient. With standard 2-layer PCB copper pour, derating is unnecessary up to +85°C ambient - confirming suitability for thermally constrained industrial enclosures.

How does the I_off feature function during system power-down sequences?

The I_off feature in SN74CBT3253CDRG4 limits current to ≤10 µA when V_CC = 0 V and any I/O port is biased (0–5.5 V), preventing damaging backflow from powered subsystems into the unpowered device. This enables safe partial-power-down operation - for example, disabling a USB port while keeping the host controller active. The high-impedance state is maintained regardless of OE or select pin states, eliminating the need for complex power sequencing or external isolation switches in multi-rail designs.