The SN74ALVCHG162280 is a 16-bit to 32-bit registered bus exchanger. This device is intended for use in applications where data must be transferred from a narrow high-speed bus to a wide lower-frequency bus. It is designed specifically for low-voltage (3.3-V) VCC operation.
The device provides synchronous data exchange between the two ports, A and B. Data is stored in the internal registers on the low-to-high transition of the clock (CLK) input. For data transfer in the B-to-A direction, the select (SEL)\ input selects 1B or 2B data for the A outputs.
For data transfer in the A-to-B direction, a two-stage pipeline is provided in the 1B path, with a single storage register in the 2B path. Data flow is controlled by the active-low output-enable (OE)\ and direction-control (DIR) inputs. DIR is registered to synchronize the bus direction changes with the clock.
Two mask bits are provided for both data bytes. The data (D) outputs are controlled by OE\.
The A-port N-channel output transistors are sized at 450 µm, and the P-channel output transistors are sized at 700 µm. All A-port outputs have equivalent 50- series resistors.
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.
Active bus-hold circuitry is provided to hold unused or floating data inputs at a valid logic level.
The switching characteristics are based on 25-pF (A port) and 80-pF (B and D ports) loads, but are tested with the standard 50-pF load.
The SN74ALVCHG162280 is characterized for operation from 0°C to 70°C.