SCDS168A May 2004 – September 2015 SN74CB3Q16244
PRODUCTION DATA.
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The SN74CB3Q16244 device is organized as four 4-bit bus switches with separate output-enable (1OE, 2OE, 3OE, 4OE) inputs. It can be used as four 4-bit bus switches, two 8-bit bus switches, or one 16-bit bus switch. When OE is low, the associated 4-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 4-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.