SCES001A - JULY 1994 - REVISED JULY 1995
Widebus and UBT are trademarks of Texas Instruments Incorporated.
The 'LVT16600 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. These 18-bit universal bus transceivers combine D-type latches and D-type flip-flops to allow data flow in transparent, latched, and clocked modes.
Data flow in each direction is controlled by output-enable (
and
), latch-enable (LEAB and LEBA),
and clock (
and
) inputs. The clock can be
controlled by the clock-enable (
and
) inputs. For
A-to-B data flow, the device operates in the transparent mode when
LEAB is high. When LEAB is low, the A data is latched if
is held at a high or low logic
level. If LEAB is low, the A-bus data is stored in the
latch/flip-flop on the high-to-low transition of
. Output enable
is active low. When
is low, the outputs are active.
When
is high, the
outputs are in the high-impedance state. Data flow for B to A is
similar to that of A to B but uses
, LEBA,
,
and
.
Active bus-hold circuitry is provided to hold unused or floating data inputs at a valid logic level.
To ensure the high-impedance state during power up or power down,
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.
The SN74LVT16600 is available in TI's shrink small-outline (DL) and thin shrink small-outline (DGG) packages, which provide twice the I/O pin count and functionality of standard small-outline packages in the same printed-circuit-board area.
The SN54LVT16600 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74LVT16600 is characterized for operation from -40°C to 85°C.