Product Selector:
LVC: High Performance HCMOS, 5V Input Tolerant
 The
communication standard IEEE 1284 was created to supply the need
for an existing defined standard for bi-directional parallel communication
between PCs and printing peripherals. Being backward compatible
with the old specification “Parallel Centronics”, this
standard offers more functionality and performance for new PCs and
peripheral products.
| Two New Low Voltage Devices |
 After
having released the octal 74ACT1284, ST is expanding its IEEE1284
portfolio by introducing two new low voltage devices. The 74LVC161284
provides 8 bi-directional data buffers and 11 control and status
buffers to accommodate all prescribed IEEE1284 signals. Package
pin configurations are optimized for flow-through data from the
peripheral (A-side) to the host (B-side).
IEEE 1284-specified pull-up and series termination resistors are
included on the device at the outputs on the cable-side B Port.
Outputs on the cable-side B Port can be configured to either an
open-drain NMOS or high-drive CMOS (±14mA) format. The cable-side
B Port can be connected to a separate power supply via pull-ups.
This allows outputs to be driven by a higher supply voltage compared
to the A Port. Outputs on the peripheral-side A Port are standard
low voltage CMOS and are designed to interface with 3.3V logic.
The cable-side B Port has overvoltage protection to allow outputs
to interface with signals that are up to 5.5V with respect to ground.
The 74LVCZ161284 improves the performance of the 74LVC161284, by
the inclusion of the PU (power-up) feature to prevent printer errors.
It forces the Y outputs (Y9 – Y19) to
a high state after power-on until one of the associated inputs (A9
– A19) goes HIGH. When associated inputs (A9
– A19) go HIGH, all (Y9 – Y19)
outputs are active.
 |
Level 1 and 2 signalling support standards for
bi-directional parallel communications
|
|
TTL input threshold
|
|
Translation capability allows outputs on the
cable to interface with 5V signals
|
|
Power-up protection (for the Z version)
|
|
Flow-through pin configuration
|
|
Replaces the function of two 74ACT1284 devices
|
|
Hysteresis on all inputs to provide a noise
margin
|
|
| |
|
|
|
