•ESD protection exceeds 2000V per MIL STD 883 Method 3015
and 200V per Machine Model
•Input Hysteresis
•Low Noise Operation
•Center Pin V
& GND
CC
•IEEE 1284 Compliant Level 1 & 2
•Overvoltage Protection on B side
QUICK REFERENCE DATA
SYMBOLPARAMETER
C
t
PLH
t
PHL
C
I
IN
OUT
CC
Propagation delay
Bn to An
Input capacitance An, DIR, HDVI = 0V or V
Output capacitance Bn, Y
n
Total supply currentVCC = 5.5V500nA
DESCRIPTION
The 74HCT1284 parallel interface chip is designed to provide an
asynchronous, 4-bit, bi-directional, parallel printer interface for
personal computers. Three additional lines are included to provide
handshaking signals between the host and the peripheral. The part
is designed to match IEEE 1284 standard.
The 4 transceiver pins (A/B 1-4) allow data transmission from the A
bus to the B bus, or from the B bus to the A bus, depending on the
state of the direction pin DIR.
The B bus and the Y5-Y7 lines have totem pole or open drain style
outputs depending on the state of the high drive enable pin HD.
The A bus only has totem pole style outputs. All inputs are TTL
compatible with at least 400mV of input hysteresis at V
CONDITIONS
T
= 25°C; GND = 0V
amb
CL = 50pF; VCC = 5V
CC
TYPICALUNIT
5.3
5.6
5pF
VO = 0V or VCC; 3-State14pF
= 5.0V.
CC
ns
ns
ORDERING INFORMATION
PACKAGESTEMPERATURE RANGEORDER CODEDRAWING NUMBER
20-pin plastic DIP0°C to +70°C74HCT1284NSOT146-1
20-pin plastic SOL0°C to +70°C7HCT1284DSOT163-1
20-pin plastic SSOP Type II0°C to +70°C74HCT1284DBSOT339-1
20-pin plastic TSSOP Type I0°C to +70°C74HCT1284PWSOT360-1
HLLLInputs LowOutputs Low
HLHZInputs HighOutputs Z
Y5A5
Y6A6
Y7A7
HHLLInputsB = A
HHHHInputsB = A
H = High Voltage
L = Low Voltage
Z = High Impedance, Off-State
SYMBOLPARAMETERCONDITIONSRATINGUNIT
V
ICC/I
V
I
V
I
OK
OUT
I
OUT
T
CC
IK
stg
DC supply voltage–0.5 to +6.5V
DC input diode currentVI < 0±20mA
I
DC input voltage
3
–2 to +7.0V
DC output diode currentVO < 0±50mA
DC output voltage
3
Output in Off or High state–0.5 to +5.5V
DC output currentOutput in Low state±50mA
Storage temperature range–65 to 150°C
Continuous current through VCC or GND±200mA
GND
NOTES:
1. Stresses beyond those listed may cause permanent damage to the device. These are stress ratings only and functional operation of the
device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to
absolute-maximum-rated conditions for extended periods may affect device reliability .
2. The performance capability of a high-performance integrated circuit in conjunction with its thermal environment can create junction
temperatures which are detrimental to reliability. The maximum junction temperature of this integrated circuit should not exceed 150°C.
3. The input and output voltage ratings may be exceeded if the input and output current ratings are observed.
RECOMMENDED OPERATING CONDITIONS
V
CC
V
V
V
I
OH
I
OL
T
amb
1998 Jul 10
DC supply voltage4.75.5V
Input voltage0V
I
High-level input voltage2.0V
IH
Low-level Input voltage0.8V
IL
High-level output current–14mA
Low-level output current14mA
Operating free-air temperature range0+70°C