Support Mixed-Mode Signal Operation

(5-V Input and Output Voltages With

3.3-V VCC)

Typical VOLP (Output Ground Bounce)

<0.8 V at VCC = 3.3 V, TA = 25°C

Support Unregulated Battery Operation

Down to 2.7 V

Ioff and Power-Up 3-State Support Hot

Insertion

Bus Hold on Data Inputs Eliminates the

Need for External Pullup/Pulldown

Resistors

Latch-Up Performance Exceeds 500 mA Per

JESD 17

ESD Protection Exceeds JESD 22

? 2000-V Human-Body Model (A114-A)

? 200-V Machine Model (A115-A)

description/ordering information

These octal transceivers are designed specifically for low-voltage (3.3-V) VCC operation, but with the capability

to provide a TTL interface to a 5-V system environment.

The ’LVTH543 devices contain two sets of D-type latches for temporary storage of data flowing in either

direction. Separate latch-enable (LEAB or 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) input must be low to enter data from A or to output data from B. If CEAB is low and

LEAB is low, the A-to-B latches are transparent; a subsequent low-to-high transition of LEAB puts the A latches

in the storage mode. With CEAB and OEAB 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 requires using the CEBA, LEBA, and OEBA

inputs.

Active bus-hold circuitry holds unused or undriven inputs at a valid logic state. Use of pullup or pulldown resistors

with the bus-hold circuitry is not recommended.

When VCC is between 0 and 1.5 V, the device is in the high-impedance state during power up or power down.

However, to ensure the high-impedance state above 1.5 V, 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.

This device is fully specified for hot-insertion applications using Ioff and power-up 3-state. The Ioff circuitry

disables the outputs, preventing damaging current backflow through the device when it is powered down. The

power-up 3-state circuitry places the outputs in the high-impedance state during power up and power down,

which prevents driver conflict.