Texas Instruments SN74CBT3253PWR

Overview

SN74CBT3253PWR from Texas Instruments is a dual 1-of-4 high-speed TTL-compatible FET multiplexer/demultiplexer in TSSOP-16 package, featuring 5 Ω typical on-state resistance at 4.5 V, <0.25 ns propagation delay (VCC = 5 V), and ±1 μA max input leakage current. It enables bidirectional signal routing in bus-switching applications such as memory address/data path selection and I²C/SMBus level translation.

For engineers reviewing the SN74CBT3253PWR datasheet, SN74CBT3253PWR pinout, SN74CBT3253PWR application, or SN74CBT3253PWR equivalent, key selection criteria include guaranteed 4–5.5 V supply operation, sub-1 ns enable/disable timing, 50 pF load-compatible switching, and compatibility with 3.3 V/5 V mixed-voltage system interconnects.

Technical Context

The SN74CBT3253PWR implements two independent 1:4 analog switches using low-threshold NMOS pass transistors, supporting bidirectional signal flow without direction control pins. Each channel uses S0/S1 address lines and dedicated OE# enables (1OE, 2OE) for independent channel gating.

Its TTL-compatible control inputs (VIH = 2 V min, VIL = 0.8 V max) interface directly with legacy 5 V logic while maintaining rail-to-rail analog signal swing across the A/B ports. The device operates with no internal biasing-signal integrity depends solely on external VCC and load conditions.

Key Specifications

Pinout & Package

TSSOP-16 package (PW), 5.0 mm × 4.4 mm × 1.2 mm height, 0.65 mm lead pitch, exposed pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3253PWR, SN74CBTD3384PWR offers greater channel density but sacrifices pin compatibility and adds complexity for power management, while TS3A27518EPWR delivers lower on-resistance at the cost of 5 V logic compatibility and increased supply sensitivity-making SN74CBT3253PWR optimal for robust, mixed-voltage industrial bus switching.

Availability

SN74CBT3253PWR is available at Aetrix Electronics and suitable for memory bus switching, I²C level translation, test equipment signal routing, and digital logic prototyping requiring stable component supply and long-term industrial availability.

Supply support for SN74CBT3253PWR 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 U.S.-based semiconductor company specializing in analog, embedded processing, and logic solutions with over 90 years of innovation in high-reliability components.

The SN74CBT3253PWR belongs to TI's CBT (Crossbar Bus Transceiver) logic family, designed specifically for high-speed, low-distortion analog signal routing in mixed-voltage digital systems.

FAQ

What is the maximum continuous current rating for each channel of the SN74CBT3253PWR?

The SN74CBT3253PWR supports up to 128 mA continuous channel current per switch path, as specified in its absolute maximum ratings. This rating applies under recommended operating conditions (VCC = 4–5.5 V, TA = −40°C to 85°C) and assumes adequate PCB thermal relief. Exceeding this current may increase on-resistance nonlinearly or accelerate parametric drift over time. The SN74CBT3253PWR does not include current-limiting circuitry, so external current limiting must be implemented if peak loads exceed 128 mA.

Does the SN74CBT3253PWR require external pull-up resistors on its control inputs (S0, S1, 1OE, 2OE)?

No, the SN74CBT3253PWR does not require external pull-up resistors on its control inputs. Its TTL-compatible input thresholds (VIH ≥ 2 V, VIL ≤ 0.8 V) allow direct connection to standard 5 V CMOS or TTL outputs. However, TI recommends tying all unused control inputs to VCC or GND to prevent floating states that could cause undefined switching behavior or increased ICC. The SN74CBT3253PWR has no internal pull-up/pull-down networks, so unconnected inputs remain electrically indeterminate.

Can the SN74CBT3253PWR operate reliably with a 3.3 V supply voltage?

No, the SN74CBT3253PWR is not rated for reliable operation at 3.3 V. Its recommended operating supply range is strictly 4 V to 5.5 V, and the datasheet specifies VIH = 2 V minimum only when VCC ≥ 4 V. At 3.3 V, the input threshold margins collapse, risking misinterpretation of logic levels and intermittent switching. For 3.3 V systems, consider TI's TS3A27518EPWR or similar 1.65–3.6 V optimized switches instead of the SN74CBT3253PWR.

Is the SN74CBT3253PWR pin-compatible with other packages in the same family, such as SN74CBT3253DBR or SN74CBT3253DR?

No, the SN74CBT3253PWR is not pin-compatible with SN74CBT3253DBR (SSOP-16) or SN74CBT3253DR (SOIC-16), despite identical pin functions. While all share the same 16-pin functional mapping, their physical footprints differ: PW (TSSOP) has 0.65 mm pitch and 5.0 × 4.4 mm body, DB (SSOP) has 0.65 mm pitch but 6.2 × 5.3 mm body, and D (SOIC) has 1.27 mm pitch and 10.2 × 6.2 mm body. PCB layout must be redesigned for each package; the SN74CBT3253PWR cannot be substituted without board revision.

What is the thermal resistance (θJA) of the SN74CBT3253PWR in its native TSSOP package?

According to TI's datasheet SCDS018O, the SN74CBT3253PWR in the PW (TSSOP-16) package has a junction-to-ambient thermal resistance (θJA) of 108°C/W, measured per JESD 51-7. This value assumes standard JEDEC 2-layer board conditions (1-inch² copper pad, 2 oz Cu). Actual θJA will improve with enhanced PCB copper area or thermal vias, but derating is required above 70°C ambient to maintain junction temperature below 125°C. The SN74CBT3253PWR's low ICC (3 μA typical) minimizes self-heating under static conditions.