|Package | PIN:||DB | 24|
|Temp:||I (-40 to 85)|
- 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)
Texas Instruments SN74LVTH543DBR
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.