ST 74LCX16245 User Manual
Low voltage CMOS 16-bit bus transceiver (3-state)
Features
■ 5V tolerant inputs and outputs
■ High speed:
–t
= 4.5ns (Max) at V
PD
■ Power down protection on inputs and outputs
■ Symmetrical output impedance:
–|I
■ PCI bus levels guaranteed at 24mA
■ Balanced propagation delays:
–t
■
Operating voltage range:
–V
■ Pin and function compatible with
| = IOL = 24mA (Min) at VCC = 3V
OH
≅ t
PLH
PHL
(Opr) = 2.0V to 3.6V
CC
74 series 16245
■ Latch-up performance exceeds
500mA (JESD 17)
■ ESD performance:
– HBM > 2000V
(MIL STD 883 method 3015); MM > 200V
CC
= 3V
74LCX16245
with 5V tolerant inputs and outputs
TSSOP48
Description
The 74LCX16245 is a low voltage CMOS 16 bit
bus transceiver (3-state) fabricated with submicron silicon gate and double-layer metal wiring
2
C
MOS technology. It is ideal for low power and
high speed 3.3V applications; it can be interfaced
to 5V signal environment for both inputs and
outputs.
This IC is intended for two-way asynchronous
communication between data buses; the direction
of data transmission is determined by DIR input.
The two enable inputs nG
the device so that the buses are effectively
isolated.
can be used to disable
It has same speed performance at 3.3V than 5V
AC/ACT family, combined with a lower power
consumption.
All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
All floating bus terminals during High Z State must
be held HIGH or LOW.
Order codes
Part number Package Packaging
74LCX16245TTR TSSOP48 Tape and reel
February 2007 Rev 7 1/15
www.st.com
15
Contents 74LCX16245
Contents
1 Logic symbols and I/O equivalent circuit . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Pin settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1 Pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3 Logic states . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1 Truth table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4 Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.1 Recommended operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6 Test circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7 Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
8 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2/15
74LCX16245 Logic symbols and I/O equivalent circuit
1 Logic symbols and I/O equivalent circuit
Figure 1. IEC logic symbols
Figure 2. Input and output equivalent circuit
3/15
Pin settings 74LCX16245
2 Pin settings
2.1 Pin connection
Figure 3. Pin connection (top through view)
4/15
74LCX16245 Logic states
2.2 Pin description
Table 1. Pin description
Pin N° Symbol Name and function
1 1DIR Directional control
2, 3, 5, 6,
8, 9, 11, 12
13, 14, 16, 17,
19, 20, 22, 23
24 2DIR Directional control
25 2G
36, 35, 33, 32,
30, 29, 27, 26
47, 46, 44, 43,
41, 40, 38, 38
48 1G
4, 10, 15, 21,
28, 34, 39, 45
7, 18, 31, 42
3 Logic states
3.1 Truth table
1B1 to 1B8 Data inputs/outputs
2B1 to 2B8 Data inputs/outputs
Output enable input
2A1 to 2A8 Data inputs/outputs
1A1 to 1A8 Data inputs/outputs
Output enable input
GND Ground (0V)
V
CC
Positive supply voltage
Table 2. Truth table
G
L L Output Input A = B
L H Input Output B = A
HXZ ZZ
Note: X : Do not care
Z : High impedance
Inputs Function Output
DIR A BUS B BUS Yn
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