Fairchild Semiconductor 74VCX16839MTDX, 74VCX16839MTD Datasheet
July 1997
Revised April 1999
74VCX16839 Low Voltage 20-Bit Selectable Register/Buffer with 3.6V Tolerant Inputs and Outputs
© 1999 Fairchild Semiconductor Corporation DS500105.prf www.fairchildsemi.com
74VCX16839
Low Voltage 20-Bit Selectable Register/Buffer with 3.6V
Tolerant Inputs and Outputs
General Description
The VCX16839 contains twenty non-inverting selectable
buffered or registered pa ths. T he dev ic e can be configured
to operate in a regis tered, or flow throu gh buffer mode by
utilizing the register enable (REGE) and Clock (CP) signals. 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 ar e ideally sui ted for buffered or registered 168 pin and 200 pin SDRAM DIMM memo ry modules.
The 74VCX16839 is designed for low voltage (1.65V to
3.6V) V
CC
applications with I/O compatibility up to 3.6V.
The 74VCX16839 is fabricated with an advanced CMOS
technology to achieve high speed operation while maintaining low CMOS power dissipation.
Features
■ Compatible with PC100 and PC133 DIMM module
specifications
■ 1.65V–3.6V V
CC
supply operation
■ 3.6V tolerant inputs and outputs
■ t
PD
(CP to On)
3.2 ns max for 3.0V to 3.6V V
CC
4.4 ns max for 2.3V to 2.7V VCC
8.8 ns max for 1.65V to 1.95V V
CC
■ Power-off high impedance inputs and outputs
■ Supports live insertion and withdrawal (Note 1)
■ Static Drive (I
OH/IOL
)
±24 mA @ 3.0V V
CC
±18 mA @ 2.3V V
CC
±6 mA @ 1.65V V
CC
■ Uses patented noise/EMI reduction circuitry
■ Latch-up performance exceeds 300 mA
■ ESD performance:
Human body model > 2000V
Machine model > 200V
Note 1: To ensure the high-impedance state d uring power up or power
down, OE
should be tied to VCC through a pull-up r esistor; the min imum
value of the res istor is d eter mine d by the cu rre nt-sou rcin g ca pa bility of t he
driver.
Ordering Code:
Devices also availab le in Tape and Reel. Specify by appending suffix letter “X” to the ordering code.
Logic Symbol Pin Descriptions
Order Number Package Number Package Descriptions
74VCX16839MTD 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–I19
Inputs
O
0–O19
Outputs
CP Clock Pulse Input
REGE Register Enable Input
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74VCX16839
Connection Diagram Tr uth Table
H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial (HIGH or LOW, inputs may not float)
Z = High Impedance
Functional Description
The 74VCX16839 con sists of twenty selectable non-inve rting buffers or registers with word wide controls. Mode functionality is selected through operation of the CP and REGE
pin as shown by the truth table. W hen REGE is hel d at a
logic “1” the device operate s as a 20-bit register. Data is
transferred from I
n
to On on the rising edge of the CP pin.
When the REGE pin i s held at a logic “ 0” the devi ce operates in a flow through mode an d data propagates direct ly
from the I
n
to the On outputs. All outputs can be 3-stated by
holding the OE
pin at a logic “1.”
Logic Diagram
Inputs Outputs
CP REGE
I
n
OE
O
n
↑ HHL H
↑ HLL L
XLHLH
XLLLL
XXXHZ
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74VCX16839
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 conditions for actual device operation.
Note 3: I
O
Absolute Maximum Rating must be observed.
Note 4: Floating or unused inputs m us t be held HIGH or LOW.
DC Electrical Characteristics (2.7V < VCC ≤ 3.6V)
Note 5: Outputs disab led or 3-STATE only.
Supply Voltage (VCC) −0.5V to +4.6V
DC Input Voltage (V
I
) −0.5V to +4.6V
Output Voltage (V
O
)
Outputs 3-STATE −0.5V to +4.6V
Outputs Active (Note 3) −0.5V to V
CC
+0.5V
DC Input Diode Current (I
IK
) VI < 0V −50 mA
DC Output Diode Current (I
OK
)
V
O
< 0V −50 mA
V
O
> V
CC
+50 mA
DC Output Source/Sink Current
(I
OH/IOL
) ±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
Data Retention Only 1.2V to 3.6V
Input Voltage −0.3V to +3.6V
Output Voltage (V
O
)
Output in Active States 0V to V
CC
Output in “OFF” State 0.0V to 3.6V
Output Current in I
OH/IOL
VCC = 3.0V to 3.6V ±24 mA
V
CC
= 2.3V to 2.7V ±18 mA
V
CC
= 1.65V to 2.3V ±6 mA
Free Air Operating Temperature (T
A
) −40°C to +85°C
Minimum Input Edge Rate (∆t/∆V)
V
IN
= 0.8V to 2.0V, VCC = 3.0V 10 ns/V
Symbol Parameter Conditions
V
CC
(V)
Min Max Units
V
IH
HIGH Level Input Voltage 2.7 − 3.6 2.0 V
V
IL
LOW Level Input Voltage 2.7 − 3.6 0.8 V
V
OH
HIGH Level Output Voltage IOH = −100 µA2.7 − 3.6 VCC − 0.2 V
IOH = −12 mA 2.7 2.2 V
IOH = −18 mA 3.0 2.4 V
IOH = −24 mA 3.0 2.2 V
V
OL
LOW Level Output Voltage IOL = 100 µA2.7 − 3.6 0.2 V
IOL = 12 mA 2.7 0.4 V
IOL = 18 mA 3.0 0.4 V
IOL = 24 mA 3.0 0.55 V
I
I
Input Leakage Current 0 ≤ VI ≤ 3.6V 2.7 − 3.6 ±5.0 µA
I
OZ
3-STATE Output Leakage 0 ≤ VO ≤ 3.6V
2.7 − 3.6 ±10 µA
VI = VIH or V
IL
I
OFF
Power-OFF Leakage Current 0 ≤ (VI, VO) ≤ 3.6V 0 10 µA
I
CC
Quiescent Supply Current VI = VCC or GND 2.7 − 3.6 20 µA
VCC ≤ (VI, VO) ≤ 3.6V (Note 5) 2.7 − 3.6 ±20 µA
∆I
CC
Increase in ICC per Input VIH = VCC −0.6V 2.7 − 3.6 750 µA
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