1 Features
1• 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 = 3 Ω Typ)
• Rail-to-Rail Switching on Data I/O Ports
– 0-V to 5-V Switching With 3.3-V VCC
– 0-V to 3.3-V Switching With 2.5-V VCC
• Bidirectional Data Flow With Near-Zero
Propagation Delay
• Low Input and Output Capacitance Minimizes
Loading and Signal Distortion
(Cio(OFF) = 4 pF Typ)
• Fast Switching Frequency (f OE = 20 MHz Max)
• Data and Control Inputs Provide Undershoot
Clamp Diodes
• Low Power Consumption
(ICC = 0.3 mA Typ)
• VCC Operating Range From 2.3 V to 3.6 V
• Data I/Os Support 0-V 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,
5-V, or 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
(SCDA008).

2 Applications
• IP Phones: Wired and Wireless
• Optical Modules
• Optical Networking: Video Over Fiber and EPON
• Private Branch Exchange (PBX)
• WiMAX and Wireless Infrastructure Equipment

3 Description
The SN74CB3Q3125 device is a high-bandwidth FET
bus switch that uses a charge pump to elevate the
gate voltage of the pass transistor, thus 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
SN74CB3Q3125 device also features low data I/O
capacitance to minimize capacitive loading and signal
distortion on the data bus.