SN74CB3Q3306A Dual FET 2.5-V/3.3-V Low-Voltage, High-Bandwidth Bus Switch |


Dual FET 2.5-V/3.3-V Low-Voltage, High-Bandwidth Bus Switch

Dual FET 2.5-V/3.3-V Low-Voltage, High-Bandwidth Bus Switch - SN74CB3Q3306A


The SN74CB3Q3306A 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 SN74CB3Q3306A provides an optimized interface solution ideally suited for broadband communications, networking, and data-intensive computing systems.

The SN74CB3Q3306A is organized as two 1-bit switches with separate output-enable (1OE, 2OE) inputs. It can be used as two 1-bit bus switches or as one 2-bit bus switch. When OE is low, the associated 1-bit bus switch is ON and the A port is connected to the B port, allowing bidirectional data flow between ports. When OE is high, the associated 1-bit bus switch is OFF, 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.


  • High-Bandwidth Data Path (up to 500 MHz(1))
  • 5-V-Tolerant I/Os With Device Powered Up or Powered Down
  • Low and Flat ON-State Resistance (ron) Characteristics Over
    Operating Range (ron = 4 Ω Typ)
  • Rail-to-Rail Switching on Data I/O Ports
    • 0- to 5-V Switching With 3.3-V VCC
    • 0- to 3.3-V Switching With 2.5-V VCC
    • Bidirectional Data Flow With Near-Zero Propagation Delay
  • Low Input/Output Capacitance Minimizes Loading and Signal Distortion
    (Cio(OFF) = 3.5 pF Typ)
  • Fast Switching Frequency (f OE = 20 MHz Max)
  • Data and Control Inputs Provide Undershoot Clamp Diodes
  • Low Power Consumption (ICC = 0.25 mA Typ)
  • VCC Operating Range From 2.3 V to 3.6 V
  • Data I/Os Support 0- to 5-V Signaling Levels
    (0.8 V, 1.2 V, 1.5 V, 1.8 V, 2.5 V, 3.3 V, 5 V)
  • Control Inputs Can Be Driven by TTL or 5-V/3.3-V CMOS Outputs
  • Ioff Supports Partial-Power-Down Mode Operation
  • Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
  • ESD Performance Tested Per JESD 22
    • 2000-V Human-Body Model (A114-B, Class II)
    • 1000-V Charged-Device Model (C101)
  • Supports Both Digital and Analog Applications: USB Interface, Differential Signal
    Interface, Bus Isolation, Low-Distortion Signal Gating

(1) For additional information regarding the performance characteristics of the CB3Q family, refer to the TI application report, CBT-C, CB3T, and CB3Q Signal-Switch Families, literature number SCDA008.

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Parametrics Compare all products in Analog switches/muxes

Number of channels (#)
Power supply type
Vss (Min) (V)
Vss (Max) (V)
Vdd (Min) (V)
Vdd (Max) (V)
Ron (Typ) (Ohms)
Bandwidth (MHz)
Operating temperature range (C)
Package Group
Supply Range (Max)
Ron (Max) (Ohms)
Input/output continuous current (Max) (mA)
Supply Current (Typ) (uA)
Supply Current (Max) (uA)
OFF-state leakage current (Max) (µA)
ON-state leakage current (Max) (µA)
CON (Typ) (pF)
COFF (Typ) (pF)
VIL (Max) (V)
VIH (Min) (V)
SN74CB3Q3306A SN74CBT3306
1:1 SPST     1:1 SPST    
2     2    
Single     Single    
2.3     4    
3.6     5.5    
4     5    
500     200    
Catalog     Catalog    
-40 to 85     -40 to 85    
VSSOP | 8    
SOIC | 8
TSSOP | 8    
3.6     5.5    
9     20    
64     128    
2000     3    
Powered-off protection
Supports I2C signals    
Supports I2C signals    
1     1    
3.5     4    
0.8     0.8    
1.7     2