© 2005 Fairchild Semiconductor Corporation DS500098 www.fairchildsemi.com
February 1998
Revised June 2005
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74VHC161284
IEEE 1284 Transceiver
General Description
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).
Outputs on the cable side can be configured to be either
open drain or high drive (c114 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 V
CC
sup-
ply to provide proper termination and pull-ups for open
drain mode.
Outputs on the Peripheral side are standard LOW-drive
CMOS outputs. The DIR input controls data flow on the A
1
–
A
8
/B
1
–B
8
transceiver pins.
Features
a73 Supports IEEE 1284 Level 1 and Level 2 signaling
standards for bidirectional parallel communications
between personal computers and printing peripherals
a73 Replaces the function of two (2) 74ACT1284 devices
a73 All inputs have hysteresis to provide noise margin
a73 B and Y output resistance optimized to drive external
cable
a73 B and Y outputs in high impedance mode during power
down
a73 Inputs and outputs on cable side have internal pull-up
resistors
a73 Flow-through pin configuration allows easy interface
between the Peripheral and Host

Ordering Code:
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
Ordering Number Package Number Package Description
74VHC161284MEA MS48A 48-Lead Small Shrink Outline Package (SSOP), JEDEC MO-118, 0.300" Wide
74VHC161284MTD MTD48 48-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide