NXP Semiconductors CBT3245ADS,112

Overview

CBT3245ADS,112 from Nexperia is an octal bus switch IC with 8 independent single-pole single-throw analog switches, controlled by a single active-low output enable (OE) input, featuring 5 Ω typical ON resistance at 4.5 V, IOFF partial power-down capability, and operation from -40 °C to +85 °C. It enables bidirectional signal routing in high-speed digital buses such as address/data lines in microcontroller or FPGA I/O expansion systems.

For engineers reviewing the CBT3245ADS,112 datasheet, CBT3245ADS,112 pinout, CBT3245ADS,112 application, or CBT3245ADS,112 equivalent, key selection considerations include its TTL-compatible control inputs, overvoltage-tolerant OE pin (up to 5.5 V), low propagation delay (<0.25 ns), and support for hot-swap and partial power-down system architectures.

Technical Context

The CBT3245ADS,112 implements a passive FET-based analog switch architecture with no internal level-shifting or buffering - signals pass through with minimal distortion and rail-to-rail voltage range (limited only by VCC and GND). Its IOFF circuitry ensures isolation between A and B ports when VCC = 0 V, preventing current backflow during power sequencing.

Each of the eight switch channels operates bidirectionally with identical ON resistance and capacitance characteristics; functional behavior is strictly governed by OE logic state (LOW = enabled, HIGH = high-impedance OFF), with no internal latching or timing dependencies beyond specified enable/disable times (1.0–6.0 ns).

Key Specifications

Pinout & Package

CBT3245ADS,112 is packaged in SSOP20 (SOT724-1), a 20-pin plastic shrink small outline package with 0.65 mm pitch and body dimensions 7.2 × 5.3 × 1.95 mm. Pin 1 index located at top-left corner; exposed thermal pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3245CPWR and 74LVC245APW, the CBT3245ADS,112 uniquely combines bidirectional switching, IOFF-enabled power sequencing, and overvoltage-tolerant control - making it the only option among the three suitable for mixed-voltage hot-plug subsystems requiring zero-current isolation during power transitions.

Availability

CBT3245ADS,112 is available at Aetrix Electronics and suitable for industrial automation interfaces, FPGA carrier board designs, and embedded microcontroller expansion modules requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for CBT3245ADS,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 delivering high-performance logic, analog, and MOSFET solutions optimized for efficiency, reliability, and manufacturability in high-volume applications.

The CBT3245ADS,112 belongs to Nexperia's CBT family of high-speed CMOS bus switches, engineered specifically for low-latency, low-distortion signal routing in industrial, computing, and communications infrastructure where power sequencing and mixed-voltage interoperability are critical.

FAQ

What is the maximum supply voltage rating for CBT3245ADS,112?

The CBT3245ADS,112 has an absolute maximum supply voltage (VCC) of +7.0 V, but its recommended operating range is 4.0 V to 5.5 V. Operating outside the recommended range may degrade RON stability, increase leakage, or reduce ESD robustness - always verify timing margins and thermal performance when using near limiting values. The CBT3245ADS,112 must not be operated continuously above 5.5 V in production systems.

Does CBT3245ADS,112 support bidirectional signal flow?

Yes, the CBT3245ADS,112 supports fully bidirectional analog signal routing between each A and B pin pair - there is no inherent directionality or internal buffering. Signals pass identically from A to B or B to A when the switch is enabled (OE = LOW), with matched ON resistance and capacitance in both directions. This makes the CBT3245ADS,112 ideal for data bus isolation and multiplexing where signal symmetry is required.

Can CBT3245ADS,112 be used in systems with mixed 3.3 V and 5 V logic domains?

Yes - the CBT3245ADS,112 supports mixed-voltage operation via its overvoltage-tolerant OE input (rated to 5.5 V) and rail-to-rail analog signal path. When VCC = 3.3 V, OE accepts 5 V control signals directly; when VCC = 5 V, A/B ports handle 0–5 V signals. However, analog signal swing must stay within VCC and GND - the CBT3245ADS,112 does not translate logic levels, only passes them.

What is the purpose of the n.c. pin on CBT3245ADS,112?

The n.c. (no-connect) pin on CBT3245ADS,112 is physically present in the SSOP20 package but internally unconnected. It must remain electrically floating - neither tied to VCC nor GND - and should not be soldered to PCB copper unless left as an isolated thermal pad. Soldering it to GND or VCC risks mechanical stress or unintended coupling; the CBT3245ADS,112 functions correctly with this pin unused.

How does IOFF functionality work in CBT3245ADS,112?

The IOFF circuitry in CBT3245ADS,112 automatically disables all eight switch channels and blocks current flow between A and B ports when VCC = 0 V - even if input/output signals remain active. This prevents back-powering of powered-down sections and meets JEDEC JESD78 latch-up immunity requirements (>500 mA). IOFF is intrinsic to the device structure and requires no external components or configuration - it activates inherently during power-down sequences in the CBT3245ADS,112.