Nexperia USA Inc. 74CB3Q3257BQX

Overview

74CB3Q3257BQX from Nexperia is a quad 1-of-2 FET bus switch with integrated charge pump, designed for high-bandwidth signal routing in 3.3 V systems switching 0–5 V signals. It features 4 Ω typical ON resistance, 3.5 pF OFF-state capacitance, and supports up to 20 MHz switching frequency. Used in memory interleaving and sensor multiplexing where level-shifting and low-distortion analog/digital signal pass-through are required.

For engineers reviewing the 74CB3Q3257BQX datasheet, 74CB3Q3257BQX pinout, 74CB3Q3257BQX application, or 74CB3Q3257BQX equivalent, key selection criteria include overvoltage tolerance (0–5 V with V_CC = 3.3 V), IOFF partial power-down support, and DHVQFN16 thermal performance for dense PCB layouts.

Technical Context

The device implements four independent NMOS transmission gates with charge-pump boosted gate drive, enabling rail-to-rail analog/digital signal switching across 0–5 V while powered at 2.3–3.6 V. Each channel has active-low OE control and single-pole double-throw (SPDT) configuration via S input.

Functional operation follows a truth table where S selects between B1 or B2 paths to common A terminal, and OE disables all channels into high-impedance state. The internal charge pump elevates NMOS gate voltage above V_CC, ensuring low R_ON flatness and consistent conduction across the full 0–5 V signal range.

Key Specifications

Pinout & Package

DHVQFN16 package (SOT763-1): 2.5 × 3.5 × 0.85 mm body, thermally enhanced, no leads, exposed thermal pad (non-soldered or floating/grounded per layout).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3257PWR and 74LVC1G3157GW, the 74CB3Q3257BQX uniquely delivers 5 V overvoltage tolerance with 3.3 V supply, IOFF-enabled power domain isolation, and quad integration - making it optimal for memory, sensor, and communication infrastructure where signal integrity and mixed-voltage interoperability are essential.

Availability

74CB3Q3257BQX is available at Aetrix Electronics and suitable for memory interleaving, bus isolation, sensor multiplexing, and communication infrastructure requiring stable component supply and guaranteed long-term sourcing.

Supply support for 74CB3Q3257BQX 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, analog, and MOSFET solutions for automotive, industrial, and consumer markets.

The 74CB3Q series targets high-speed, low-distortion signal routing in mixed-voltage systems - specifically engineered for applications demanding 5 V signal compatibility with 3.3 V logic supplies and robust ESD/latch-up immunity.

FAQ

What is the maximum signal voltage that can be switched with V_CC = 3.3 V?

The 74CB3Q3257BQX supports 0 V to 5 V signal switching when V_CC = 3.3 V, enabled by its internal charge pump that boosts NMOS gate voltage above V_CC. This allows full rail-to-rail analog and digital signal pass-through without level-shifting circuitry, verified per datasheet Table 5 and functional description Section 1.

Does the DHVQFN16 package require soldering of the exposed thermal pad?

No - the exposed pad (Pin 1 index area) has no electrical or mechanical requirement to be soldered. If connected, it must remain electrically floating or tied to GND per datasheet Section 6.1. Soldering is optional and used only for thermal enhancement; improper grounding may compromise ESD performance or cause ground loops.

How does IOFF protect the device during partial power-down?

When V_CC = 0 V, IOFF limits leakage current to ±1 μA per pin (Table 6), preventing back-current flow from live signal lines into unpowered sections. This avoids unintended biasing, latch-up risk, or data corruption in hot-swap or multi-rail systems - confirmed by static characteristics testing at V_CC = 0 V.

Can S and OE be driven directly from 5 V microcontroller GPIOs?

Yes - both S and OE accept input voltages from 0 V to 5.5 V independent of V_CC, as specified in Table 5 (VI input voltage range). This TTL/5 V CMOS compatibility eliminates external level shifters when interfacing with legacy or mixed-voltage controllers.