A-2
Appendix A Interfacing the L64005 to 5-V Signals
Final Rev F
Copyright 1996 by LSI Logic Corporation. All rights reserved.
The 3.3-V L64005 IC complies with the JEDEC JESD8-1 specication
and meets all the DC-level specications required to interface to a tradi-
tional 5-V TTL part. This allows a L64005 IC to be functionally compati-
ble with older 5-V devices.
The JESD8-1 does not specify the limits of exposing the 3.3-V device to
input levels that exceed a 3.3-V VDD supply. JESD8-1A species a max-
imum DC input voltage of VDD + 0.3V. External devices that specify a
maximum VIH that tolerates the maximum VOH of a 5-V IC can exceed
JESD8-1A specied maximum DC input voltage. The technology used for
L64005 provides this capability.
A.2
L64005
5V-Compatible
I/Os
Five congurations that interface the L64005 to 5-V ICs require
5-V compatible buffers:
an L64005 input buffer that receives a CMOS or TTL signal from a
5-V IC
an L64005 output buffer that drives a TTL input on a 5-V IC
an L64005 output buffer that drives a TTL or CMOS input on a 5V
IC using an open drain conguration
L64005 3-state output buffer that coexists on a common bus with one
or more 5-V ICs.
A bidirectional buffer that combines an input buffer with one of the
three output buffers described above.
Figure A.1 illustrates the possible congurations.
Table A.11
DC Logic Levels
Sym
Parameter
Conditions
Min
Typ
Max
Unit
VIH
High-level input Voltage
2.0
VDD + 0.3V
V
VIL
Low-level input Voltage
-0.3V
0.8
V
VOH
High-level Output Voltage,
TTL- Compatible
VDD = min
IOH = -2 mA
2.4
VOL
Low-level Output Voltage,
TTL- Compatible
VDD = min
IOL = 2 mA
0.4
VDD
Power Supply
Voltage
Military
Commercial
3.0
3.15
3.3
3.6
3.45
V