74HC_HCT7540 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
Product data sheet Rev. 4 — 31 December 2012 3 of 16
NXP Semiconductors
74HC7540; 74HCT7540
Octal Schmitt trigger buffer/line driver; 3-state; inverting
5.2 Pin description
6. Functional description
[1] H = HIGH voltage level; L = LOW voltage level; X = don’t care; Z = high-impedance OFF-state.
7. Limiting values
[1] The input and output voltage ratings may be exceeded if the input and output current ratings are observed.
[2] For DIP20 packages: above 70 C the value of P
tot
derates linearly with 12 mW/K.
For SO20 packages: above 70 C the value of P
tot
derates linearly with 8 mW/K.
For SSOP20 packages: above 60 C the value of P
tot
derates linearly with 5.5 mW/K.
Table 2. Pin description
Symbol Pin Description
OE
1 1 output enable input (active LOW)
A0 to A7 2, 3, 4, 5, 6, 7, 8, 9 data input
GND 10 ground (0 V)
Y
0 to Y7 18, 17, 16, 15, 14, 13, 12, 11 data output
OE
2 19 output enable input (active LOW)
V
CC
20 supply voltage
Table 3. Functional table
[1]
Control Input Output
OE1 OE2 An Yn
LL L H
LL H L
XH X Z
HX X Z
Table 4. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134). Voltages are referenced to GND (ground = 0 V).
Symbol Parameter Conditions Min Max Unit
V
CC
supply voltage 0.5 +7 V
I
IK
input clamping current V
I
< 0.5 V or V
I
>V
CC
+0.5 V
[1]
- 20 mA
I
OK
output clamping current V
O
< 0.5 V or V
O
>V
CC
+0.5V
[1]
- 20 mA
I
O
output current 0.5 V < V
O
< V
CC
+0.5V - 35 mA
I
CC
supply current - 70 mA
I
GND
ground current 70 - mA
T
stg
storage temperature 65 +150 C
P
tot
total power dissipation
[2]
DIP20 - 750 mW
SO20, SSOP20 - 500 mW
