The SN74CBTD3305CD 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 SN74CBTD3305CD 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 SN74CBTD3305CD 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 high, 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 low, 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 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 GND through a pulldown resistor; the minimum value of the resistor is determined by the current-sourcing capability of the driver.
Feature
- 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 = 3Typical)
- 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
