Overview
The SN74CB3Q3257PWE4, produced by Texas Instruments, is a high-bandwidth FET bus switch designed for multiplexing and demultiplexing applications. This device utilizes a charge pump to elevate the gate voltage of the pass transistor, providing a low and flat ON-state resistance (ron), which enables minimal propagation delay and supports rail-to-rail switching on the data input/output (I/O) ports. It is organized as two 1-of-4 multiplexers/demultiplexers with separate output-enable inputs, allowing for bidirectional data flow between ports when enabled and a high-impedance state when disabled. The device is fully specified for partial-power-down applications and features isolation during power off, making it suitable for a variety of high-bandwidth applications in broadband communications, networking, and data-intensive computing systems.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| High-Bandwidth Data Path | Up to 500 MHz | |
| ON-State Resistance (ron) | 4 Ω (Typical) | |
| VCC Operating Range | 2.3 V to 3.6 V | |
| Data I/O Signal Levels | 0 to 5 V | |
| Input/Output Capacitance (Cio(OFF)) | 3.5 pF (Typical) | |
| Switching Frequency (fOE) | 20 MHz (Max) | |
| Power Consumption (ICC) | 0.6 mA (Typical) | |
| ESD Performance | 2000 V Human Body Model, 1000 V Charged-Device Model | |
| Package Options | TVSOP (16), SSOP (16), TSSOP (16), VQFN (16) |
Key Features
- High-bandwidth data path up to 500 MHz
- 5V tolerant I/Os with the device powered up or powered down
- Low and flat ON-state resistance (ron)
- Rail-to-rail switching on data I/O ports
- Bidirectional data flow with near-zero propagation delay
- Low input/output capacitance to minimize capacitive loading and signal distortion
- Support for partial-power-down mode operation using Ioff
- Latch-up performance exceeds 100 mA per JESD 78, Class II
- ESD performance tested per JESD 22 – 2000 V Human Body Model, 1000 V Charged-Device Model
- Control inputs can be driven by TTL or 5V / 3.3V CMOS outputs
Applications
- IP Phones: wired and wireless
- Optical modules
- Optical networking: video over fiber and EPON
- Private branch exchange (PBX)
- WiMAX and wireless infrastructure equipment
- USB interface, differential signal interface, bus isolation, low-distortion signal gating
Q & A
- What is the primary function of the SN74CB3Q3257 device?
The SN74CB3Q3257 is a high-bandwidth FET bus switch used for multiplexing and demultiplexing applications.
- What is the maximum bandwidth of the SN74CB3Q3257?
The device supports a high-bandwidth data path up to 500 MHz.
- What are the VCC operating range and data I/O signal levels for the SN74CB3Q3257?
The VCC operating range is from 2.3 V to 3.6 V, and the data I/Os support 0 to 5 V signal levels.
- How does the SN74CB3Q3257 handle partial-power-down mode operation?
The device features Ioff circuitry that prevents damaging current backflow through the device when it is powered down and ensures isolation during power off.
- What types of ESD performance does the SN74CB3Q3257 have?
The device has ESD performance tested per JESD 22 – 2000 V Human Body Model, 1000 V Charged-Device Model.
- Can the control inputs of the SN74CB3Q3257 be driven by different types of logic outputs?
Yes, the control inputs can be driven by TTL or 5V / 3.3V CMOS outputs.
- What is the typical power consumption of the SN74CB3Q3257?
The typical power consumption is 0.6 mA.
- What are some common applications of the SN74CB3Q3257?
Common applications include IP phones, optical modules, optical networking, private branch exchange (PBX), and WiMAX and wireless infrastructure equipment.
- How does the SN74CB3Q3257 minimize signal distortion?
The device features low data I/O capacitance to minimize capacitive loading and signal distortion on the data bus.
- What types of packages are available for the SN74CB3Q3257?
The device is available in TVSOP, SSOP, TSSOP, and VQFN packages.
