Undershoot Protection for Off-Isolation on
A and B Ports Up To −2 V
Integrated Diode to VCC Provides 5-V Input
Down To 3.3-V Output Level Shift
Bidirectional Data Flow, With Near-Zero
Propagation Delay
Low ON-State Resistance (ron)
Characteristics (ron = 3 Ω Typical)
Low Input/Output Capacitance Minimizes
Loading and Signal Distortion
(Cio(OFF) = 5 pF Typical)
Data and Control Inputs Provide
Undershoot Clamp Diodes
VCC Operating Range From 4.5 V to 5.5 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, Memory
Interleaving, Bus Isolation, Low-Distortion
Signal Gating

description/ordering information
The SN74CBTD3306C is a high-speed TTL-compatible FET bus switch with low ON-state resistance (ron),
allowing for minimal propagation delay. This device features an integrated diode in series with VCC to provide
level shifting for 5-V input down to 3.3-V output levels. Active Undershoot-Protection Circuitry on the A and B
ports of the SN74CBTD3306C provides protection for undershoot up to −2 V by sensing an undershoot event
and ensuring that the switch remains in the proper OFF state.
The SN74CBTD3306C is organized as two 1-bit bus 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.