February 1998
Revised July 2000
74VHC161284
IEEE 1284 Transceiver
General Description
Features
■ Supports IEEE 1284 Level 1 and Level 2 signaling
standards for bidirectional parallel communications
between personal computers and printing peripherals
The VHC161284 contains eight bidirectional data buffers
and eleven control/status buffers to implement
a full
IEEE 1284 compliant interface. The device supports the
IEEE 1284 standard and is intended to be used in
Extended Capabilities Port mode (ECP). The pinout allows
for easy connection from the Peripheral (A-side) to the
Host (cable side).
■ Replaces the function of two (2) 74ACT1284 devices
■ All inputs have hysteresis to provide noise margin
■ B and Y output resistance optimized to drive external
cable
Outputs on the cable side can be configured to be either
open drain or high drive (± 14 mA). The pull-up and pull-
down series termination resistance of these outputs on the
cable side is optimized to drive an external cable. In addi-
tion, all inputs (except HLH) and outputs on the cable side
contain internal pull-up resistors connected to the VCC sup-
■ B and Y outputs in high impedance mode during power
down
■ Inputs and outputs on cable side have internal pull-up
resistors
■ Flow-through pin configuration allows easy interface
ply to provide proper termination and pull-ups for open
drain mode.
between the Peripheral and Host
Outputs on the Peripheral side are standard LOW-drive
CMOS outputs. The DIR input controls data flow on the
A1–A8/B1–B8 transceiver pins.
Ordering Code:
Ordering Number Package Number
Package Description
74VHC161284MEA
74VHC161284MTD
MS48A
MTD48
48-Lead Small Shrink Outline Package (SSOP), JEDEC MO-118, 0.300 Wide
48-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide
Surface mount packages are also available on Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Logic Symbol
Connection Diagram
© 2000 Fairchild Semiconductor Corporation
DS500098
www.fairchildsemi.com