IDT74LVCHR16543A

NOTE:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability.

The IDT74LVCHR16543A 16-bit registered transceiver is built using advanced dual metal CMOS technology. The LVCHR16543A device can be used as two independent 8-bit transceivers or one 16-bit transceiver. Separate latch-enable (LEBAor LEBA) and output-enable(OEAB or OEBA) inputs are provided for each register to permit independent control in either direction of data flow. The A-to-B enable (CEAB) must be low in order to enter data from A or to output data from B. If CEABis low and LEABis low, the Ato- B latches are transparent; a subsequent low-to-high transition of LEABputs the A latches in the storage mode. With CEABand OEABboth low, the 3-state B outputs of the IDT74LVCHR16543A are active and reflect the data present at the output of the A latches. Data flow from B to A is similar, but requires using the CEBA, LEBA, and OEBAinputs. To ensure the high-impedance state during power up or power down, OEshould be tied to Vcc through a pullup resistor; the minmum value of the resistor is determined by the current sinking capability of the driver.

The IDT74LVCHR16543A has series resistors in the device output structure which will significantly reduce line noise when used with light loads. The driver has been designed to drive ±12mA at the designated threshold levels. Inputs can be driven from either 3.3V or 5V devices. This feature allows the use of this device as a translator in a mixed 3.3V/5V supply system.

The IDT74LVCHR16543A has "bus-hold" which retains the input's last state whenever the input goes to a high impedance. This prevents floating inputs and eliminates the need for pull-up/down resistors.