SN74CBTD3306C

• Undershoot Protection for Off-Isolation on A and B Ports Up To –2 V
• Integrated Diode to V_CC Provides 5-V Input Down To 3.3-V Output Level Shift
• Bidirectional Data Flow, With Near-Zero Propagation Delay
• Low ON-State Resistance (r_on) Characteristics (r_on = 3 Typical)
• Low Input/Output Capacitance Minimizes Loading and Signal Distortion (C_io(OFF) = 5 pF Typical)
• Data and Control Inputs Provide Undershoot Clamp Diodes
• V_CC 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
• I_off 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

The SN74CBTD3306C is a high-speed TTL-compatible FET bus switch with low ON-state resistance (r_on), allowing for minimal propagation delay. This device features an integrated diode in series with V_CC 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.

This device is fully specified for partial-power-down applications using I_off. The I_off feature ensures that damaging current will not backflow through the device when it is powered down.

To ensure the high-impedance state during power up or power down, OE\ should be tied to V_CC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.