The SN74CB3Q3251 is a high-bandwidth FET bus switch utilizing a charge pump to elevate the gate voltage of the pass transistor, providing a low and flat ON-state resistance (ron). The low and flat ON-state resistance allows for minimal propagation delay and supports rail-to-rail switching on the data input/output (I/O) ports. The device also features low data I/O capacitance to minimize capacitive loading and signal distortion on the data bus. Specifically designed to support high-bandwidth applications, the SN74CB3Q3251 provides an optimized interface solution ideally suited for broadband communications, networking, and data-intensive computing systems.
The SN74CB3Q3251 is a 1-of-8 multiplexer/demultiplexer with a single output-enable (OE) input. The select (S0, S1, S2) inputs control the data path of the multiplexer/demultiplexer. When OE is low, the multiplexer/demultiplexer is enabled, and the A port is connected to the B port, allowing bidirectional data flow between ports. When OE is high, the multiplexer/demultiplexer is disabled, and a high-impedance state exists between the A and B ports.
This device is fully specified for partial-power-down applications using Ioff. The Ioff circuitry prevents damaging current backflow through the device when it is powered down. The device has isolation during power off.
To ensure the high-impedance state during power up or power down, OE should be tied to VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
| Configuration | 8 |
| Number of channels | 1 |
| Power supply voltage - single (V) | 2.5, 3.3 |
| Protocols | Analog |
| Ron (typ) (Ω) | 3.5 |
| CON (typ) (pF) | 15 |
| Supply current (typ) (µA) | 600 |
| Bandwidth (MHz) | 500 |
| Operating temperature range (°C) | -40 to 85 |
| Features | Powered-off protection, Supports input voltage beyond supply |
| Input/output continuous current (max) (mA) | 64 |
| Rating | Catalog |
| Drain supply voltage (max) (V) | 3.6 |
| Supply voltage (max) (V) | 3.6 |
| SSOP (DBQ) | 16 | 29.4 mm² 4.9 x 6 |
| TSSOP (PW) | 16 | 32 mm² 5 x 6.4 |
| TVSOP (DGV) | 16 | 23.04 mm² 3.6 x 6.4 |
| VQFN (RGY) | 16 | 14 mm² 4 x 3.5 |