2001 Fairchild Semiconductor Corporation
DS500712
www.fairchildsemi.com
November 2001
Revised November 2001
7
4
AL
VC1628
39 Low
V
o
l
t
a
ge 20
-Bit
S
e
lect
abl
e
Regi
ster
/Buf
fer
wi
th
3.6
V
T
o
l
e
rant
I
nputs
/
Outpu
t
s
and 2
6
Seri
es
Res
i
st
ors in the
O
u
tp
uts
74ALVC162839
Low Voltage 20-Bit Selectable Register/Buffer
with 3.6V Tolerant Inputs/Outputs
and 26
Series Resistors in the Outputs
General Description
The ALVC162839 contains twenty non-inverting selectable
buffered or registered paths. The device can be configured
to operate in a registered, or flow through buffer mode by
utilizing the register enable (REGE) and Clock (CLK) sig-
nals. The device operates in a 20-bit word wide mode. All
outputs can be placed into 3-STATE through use of the OE
pin. These devices are ideally suited for buffered or regis-
tered 168 pin and 200 pin SDRAM DIMM memory mod-
ules.
The 74ALVC162839 is designed for low voltage (1.65V to
3.6V) V
CC
applications with I/O compatibility up to 3.6V.
The 74ALVC162839 is also designed with 26
series
resistors in the outputs. This design reduces line noise in
applications such as memory address drivers, clock driv-
ers, and bus transceivers/transmitters.
The 74ALVC162839 is fabricated with an advanced CMOS
technology to achieve high speed operation while maintain-
ing low CMOS power dissipation.
Features
s
Compatible with PC100 and PC133 DIMM module
specifications
s
1.65V3.6V V
CC
supply operation
s
3.6V tolerant inputs and outputs
s
26
series resistors in the outputs
s
t
PD
(CLK to O
n
)
4.6 ns max for 3.0V to 3.6V V
CC
6.3 ns max for 2.3V to 2.7V V
CC
9.8 ns max for 1.65V to 1.95V V
CC
s
Power-off high impedance inputs and outputs
s
Supports live insertion and withdrawal (Note 1)
s
Uses patented noise/EMI reduction circuitry
s
Latchup conforms to JEDEC JED78
s
ESD performance:
Human body model
>
2000V
Machine model
>
200V
Note 1: To ensure the high-impedance state during power up or power
down, OE should be tied to V
CC
through a pull-up resistor; the minimum
value of the resistor is determined by the current-sourcing capability of the
driver.
Ordering Code:
Devices also available in Tape and Reel. Specify by appending suffix letter "X" to the ordering code.
Logic Symbol
Pin Descriptions
Order Number
Package Number
Package Description
74ALVC162839T
MTD56
56-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide
Pin Names
Description
OE
Output Enable Input (Active LOW)
I
0
I
19
Inputs
O
0
O
19
Outputs
CLK
Clock Input
REGE
Register Enable Input
www.fairchildsemi.com
2
74AL
VC162839
Connection Diagram
Truth Table
H
=
Logic HIGH
L
=
Logic LOW
X
=
Don't Care, but not floating
Z
=
High Impedance
=
LOW-to-HIGH Clock Transition
Functional Description
The 74ALVC162839 consists of twenty selectable non-
inverting buffers or registers with word wide modes. Mode
functionality is selected through operation of the CLK and
REGE pin as shown by the truth table. When REGE is held
at a logic HIGH the device operates as a 20-bit register.
Data is transferred from I
n
to O
n
on the rising edge of the
CLK input. When the REGE pin is held at a logic LOW the
device operates in a flow through mode and data propa-
gates directly from the I
n
to the O
n
outputs. All outputs can
be 3-stated by holding the OE pin at a logic HIGH.
Logic Diagram
Inputs
Outputs
CLK
REGE
I
n
OE
O
n
H
H
L
H
H
L
L
L
X
L
H
L
H
X
L
L
L
L
X
X
X
H
Z
3
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7
4
AL
VC1628
39
Absolute Maximum Ratings
(Note 2)
Recommended Operating
Conditions
(Note 4)
Note 2: The Absolute Maximum Ratings are those values beyond which
the safety of the device cannot be guaranteed. The device should not be
operated at these limits. The parametric values defined in the Electrical
Characteristics tables are not guaranteed at the Absolute Maximum Rat-
ings. The "Recommended Operating Conditions" table will define the condi-
tions for actual device operation.
Note 3: I
O
Absolute Maximum Rating must be observed.
Note 4: Floating or unused control inputs must be held HIGH or LOW.
DC Electrical Characteristics
Supply Voltage (V
CC
)
-
0.5V to
+
4.6V
DC Input Voltage (V
I
)
-
0.5V to 4.6V
Output Voltage (V
O
) (Note 3)
-
0.5V to V
CC
+
0.5V
DC Input Diode Current (I
IK
)
V
I
<
0V
-
50 mA
DC Output Diode Current (I
OK
)
V
O
<
0V
-
50 mA
DC Output Source/Sink Current
(I
OH
/I
OL
)
50 mA
DC V
CC
or GND Current per
Supply Pin (I
CC
or GND)
100 mA
Storage Temperature Range (T
STG
)
-
65
C to
+
150
C
Power Supply
Operating
1.65V to 3.6V
Input Voltage
0V to V
CC
Output Voltage (V
O
)
0V to V
CC
Free Air Operating Temperature (T
A
)
-
40
C to
+
85
C
Minimum Input Edge Rate (
t/
V)
V
IN
=
0.8V to 2.0V, V
CC
=
3.0V
10 ns/V
Symbol
Parameter
Conditions
V
CC
Min
Max
Units
(V)
V
IH
HIGH Level Input Voltage
1.65 - 1.95
0.65 x V
CC
V
2.3 - 2.7
1.7
2.7 - 3.6
2.0
V
IL
LOW Level Input Voltage
1.65 - 1.95
0.35 x V
CC
V
2.3 - 2.7
0.7
2.7 - 3.6
0.8
V
OH
HIGH Level Output Voltage
I
OH
=
-
100
A
1.65 - 3.6
V
CC
- 0.2
V
I
OH
=
-
2 mA
1.65
1.2
I
OH
=
-
4 mA
2.3
1.9
I
OH
=
-
6 mA
2.3
1.7
3.0
2.4
I
OH
=
-
8 mA
2.7
2
I
OH
=
-
12 mA
3.0
2
V
OL
LOW Level Output Voltage
I
OL
=
100
A
1.65 - 3.6
0.2
V
I
OL
=
2 mA
1.65
0.45
I
OL
=
4 mA
2.3
0.4
I
OL
=
6 mA
2.3
0.55
3.0
0.55
I
OL
=
8 mA
2.7
0.6
I
OL
=
12 mA
3.0
0.8
I
I
Input Leakage Current
0
V
I
3.6V
1.65 - 3.6
5.0
A
I
OZ
3-STATE Output Leakage
0
V
O
3.6V, V
I
=
V
IH
or V
IL
1.65 - 3.6
10
A
I
OFF
Power Off Leakage Current
0V
(V
I
, V
O
)
3.6V
0
10
mA
I
CC
Quiescent Supply Current
V
I
=
V
CC
or GND, I
O
=
0
3.6
40
A
I
CC
Increase in I
CC
per Input
V
IH
=
V
CC
-
0.6V
2.7 - 3.6
750
A
5
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7
4
AL
VC1628
39
AC Loading and Waveforms
FIGURE 1. AC Test Circuit
TABLE 1. Values for Figure 1
TABLE 2. Variable Matrix
(Input Characteristics: f = 1MHz; t
r
= t
f
= 2ns; Z
0
= 50
)
FIGURE 2. Waveform for Inverting and
Non-Inverting Functions
FIGURE 3. 3-STATE Output High Enable and Disable
Times for Low Voltage Logic
FIGURE 4. 3-STATE Output Low Enable and Disable Times for Low Voltage Logic
FIGURE 5. Propagation Delay, Pulse Width and
t
rec
Waveforms
FIGURE 6. Setup Time, Hold Time and
Recovery Time for Low Voltage Logic
TEST
SWITCH
t
PLH
, t
PHL
Open
t
PZL
, t
PLZ
V
L
t
PZH
, t
PHZ
GND
Symbol
V
CC
3.3V
0.3V
2.7V
2.5V
0.2V
1.8V
0.15V
V
mi
1.5V
1.5V
V
CC
/2
V
CC
/2
V
mo
1.5V
1.5V
V
CC
/2
V
CC
/2
V
X
V
OL
+
0.3V
V
OL
+
0.3V
V
OL
+
0.15V
V
OL
+
0.15V
V
Y
V
OH
-
0.3V
V
OH
-
0.3V
V
OH
-
0.15V
V
OH
-
0.15V
V
L
6V
6V
V
CC
*2
V
CC
*2
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