SN54ALVTH16543, SN74ALVTH16543
2.5-V/3.3-V 16-BIT REGISTERED TRANSCEIVERS
WITH 3-STATE OUTPUTS

SCES073A - JUNE 1996 - REVISED JULY 1996

features

• Members of the Texas Instruments Widebus^TM Family
• High-Impedance State During Power Up and Power Down
• 5-V I/O Compatible
• High-Drive Outputs (-32 mA/64 mA)
• Typical V_OLP (Output Ground Bounce) < 0.8 V at V_CC = 3.3 V, T_A = 25°C
• Auto 3-State Eliminates Bus Current Loading When Voltage at the Output Exceeds V_CC
• Bus-Hold Data Inputs Eliminate the Need for External Pullup/Pulldown Resistors
• Power Off Disables Inputs/Outputs, Permitting Live Insertion
• Package Options Include Plastic 300-mil Shrink Small-Outline (DL), Thin Shrink Small-Outline (DGG), Thin Very Small-Outline (DGV) Packages, and 380-mil Fine-Pitch Ceramic Flat (WD) Package

Widebus is a trademark of Texas Instruments Incorporated.

description

The 'ALVTH16543 are 16-bit registered transceivers designed for 2.5-V or 3.3-V V_CC operation, but with the capability to provide a TTL interface to a 5-V system environment. These devices can be used as two 8-bit transceivers or one 16-bit transceiver. Separate latch-enable (or ), output-enable (or ), and chip-enable ( or ) inputs are provided for each register to permit independent control in either direction of data flow.

The A-to-B enable () input must be low to enter data from A or to output data from B. If is low and is low, the A-to-B latches are transparent; a subsequent low-to-high transition of puts the A latches in the storage mode. With and both low, the 3-state B outputs are active and reflect the data present at the output of the A latches. Data flow from B to A is similar but uses the , , and inputs.

Active bus-hold circuitry is provided to hold unused or floating data inputs at a valid logic level.

When V_CC is between 0 and 1.2 V, the device is in the high-impedance state during power up or power down. However, to ensure the high-impedance state above 1.2 V, 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.

The SN74ALVTH16543 is available in TI's thin very small-outline package (DGV), which provides the same I/O pin count and functionality of standard Widebus packages in less than half the printed circuit board area.

The SN54ALVTH16543 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ALVTH16543 is characterized for operation from -40°C to 85°C.