Nexperia USA Inc. CBT3251PW,112

Overview

CBT3251PW,112 from Nexperia is a 1-of-8 FET bus switch (SP8T) with active-low output enable and three binary select inputs (S0–S2), designed for high-speed signal routing in digital logic interfaces. It delivers 5 Ω typical ON resistance at 5 V, <0.25 ns propagation delay, and supports bidirectional signal flow between A and any of eight B ports. Used in address/data bus multiplexing, test access port switching, and FPGA I/O expansion.

For engineers reviewing the CBT3251PW,112 datasheet, CBT3251PW,112 pinout, CBT3251PW,112 application, or CBT3251PW,112 equivalent, key selection criteria include ON-resistance matching, TTL-compatible control thresholds, IOFF power-down behavior, and TSSOP16 thermal performance under 128 mA per channel.

Technical Context

The CBT3251PW implements an NMOS-only transmission gate architecture with integrated level-shifting circuitry, enabling direct interface to 3.3 V or 5 V TTL logic while maintaining overvoltage tolerance up to 5.5 V on control pins. Its IOFF feature ensures isolation between A and B ports when VCC = 0 V, preventing back-drive current during partial power-down.

Switching is controlled by synchronous decoding of S2:S0 (3-bit binary) with OE acting as global enable. All timing parameters-including 1.5–5.6 ns enable/disable times-are specified across -40 °C to +85 °C and 4.5–5.5 V supply, with RON measured at VI = 0 V / II = 64 mA and VI = 2.4 V / II = -15 mA.

Key Specifications

Pinout & Package

TSSOP16 package (SOT403-1): 4.4 mm body width, 0.65 mm lead pitch, 1.20 mm max height, JEDEC MO-153 compliant. Designed for fine-pitch PCB assembly and improved thermal dissipation vs SO16.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 1-of-8 bus switch applications.

Compared with SN74CBT3251PWR and 74LVC1G3157GW, the CBT3251PW offers superior channel count integration, lowest RON, and native TSSOP16 thermal performance-making it optimal for space-constrained, high-current bus switching where single-device 1-of-8 routing is mandatory.

Availability

CBT3251PW,112 is available at Aetrix Electronics and suitable for FPGA I/O expansion, JTAG test access routing, and memory address multiplexing requiring stable component supply, consistent parametric performance, and long-term industrial lifecycle support.

Supply support for CBT3251PW,112 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

Nexperia is a global semiconductor expert focused on high-volume, high-reliability logic, discrete, and MOSFET solutions, with roots in NXP's standard logic division and headquartered in Nijmegen, Netherlands.

The CBT series targets high-speed, low-RON analog switching for digital interface consolidation, emphasizing minimal propagation delay, IOFF safety, and robust ESD/latch-up immunity in industrial and computing applications.

FAQ

Can CBT3251PW,112 operate with 3.3 V logic control signals while powered at 5 V?

Yes. The control inputs (OE, S0–S2) are overvoltage tolerant up to 5.5 V and accept TTL-level thresholds (VIL ≤ 0.8 V, VIH ≥ 2.0 V), allowing direct interfacing with 3.3 V microcontrollers even when VCC = 5 V. No level-shifting circuitry is required.

What happens to the A and B ports when VCC = 0 V?

When VCC is removed, the IOFF circuitry activates, forcing all switch paths into high-impedance state. This prevents current flow between A and any B port-even if one side is live-ensuring safe partial power-down and hot-swap compatibility per JEDEC JESD78 requirements.

Is the n.c. pin (pin 6) required to be grounded or left floating?

Pin 6 is a true no-connect with no internal bond wire or silicon connection. It may be left floating or tied to GND for mechanical stability; neither choice affects electrical performance. PCB layout guidelines recommend grounding unused pins only if adjacent to sensitive analog traces to reduce parasitic coupling.

How does CBT3251PW,112 handle bidirectional signal flow between A and B ports?

The device uses symmetrical NMOS transmission gates without directionality-signals pass equally well from A to Bn or Bn to A. Propagation delay (0.25 ns max) and ON resistance (5 Ω typ) are identical in both directions, supporting true bidirectional protocols like I²C, JTAG, and shared memory buses without added latency asymmetry.