The LVTH16501 devices are 18-bit universal bus transceivers designed for low-voltage (3.3-V) VCC operation, but with the capability to provide a TTL interface to a 5-V system environment.
Data flow in each direction is controlled by output-enable (OEAB and OEBA), latch-enable (LEAB and LEBA), and clock (CLKAB and CLKBA) inputs. For A-to-B data flow, the devices operate in the transparent mode when LEAB is high. When LEAB is low, the A data is latched if CLKAB is held at a high or low logic level. If LEAB is low, the A data is stored in the latch/flip-flop on the low-to-high transition of CLKAB. When OEAB is high, the outputs are active. When OEAB is low, the outputs are in the high-impedance state.
Data flow for B to A is similar to that of A to B but uses OEBA, LEBA, and CLKBA. The output enables are complementary (OEAB is active high and OEBA is active low).
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 devices are 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 and OE should be tied to GND through a pulldown resistor; the minimum value of the resistor is determined by the current-sinking/current-sourcing capability of the driver.
These devices are 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 devices when they are 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.
Widebus and UBT are trademarks of Texas Instruments.
|Part number||Order||Technology Family||VCC (Min) (V)||VCC (Max) (V)||Channels (#)||IOL (Max) (mA)||IOH (Max) (mA)||ICC @ nom voltage (Max) (mA)||Input type||Output type||Rating||Operating temperature range (C)||Package Group|
||LVT||2.7||3.6||18||64||-32||5||TTL-Compatible CMOS||3-State||Catalog||-40 to 85||
SSOP | 56
TSSOP | 56