MK74CB218
Dual 1 to 8 BuffaloTM Clock Driver
MDS 74CB218 A
1
Revision 021600 Printed 11/16/00
IntegratedCircuit Systems, Inc. 525 Race Street San Jose CA 95126(408) 295-9800tel www.icst.com
P R E L I M I N A R Y I N F O R M A T I O N
Tiny 28 pin SSOP (150 mil) package
Dual one input to eight output clock drivers
Outputs are skew matched to within 250 ps
A outputs and B outputs matched to 250 ps
2.5 V, 3.3 V or 5 V supply voltages
Output Enable tri-states each bank of eight
Clock speeds up to 200 MHz
The MK74CB218 BuffaloTM is a monolithic
CMOS high speed clock driver. It consists of two
identical single input to eight low-skew output,
non-inverting clock drivers. This eliminates
concerns of part to part matching in many
systems. The MK74CB218 is packaged in the
tiny 28 pin SSOP, which uses the same board
space as the narrow 16 pin SOIC. The inputs can
be connected together for a 1 to 16 fanout buffer.
A quad 1 to 4, and PECL versions, are also
available. Consult ICS for more details.
The MK74CB218 can also act as a voltage
translator, since it is possible to run the inputs at
3.3 V and the outputs at 2.5 V.
QB0
Block Diagram
Description
Features
Family of ICS Parts
The MK74CB218 BuffaloTM is designed to be used
with ICS's clock synthesizer devices. The inputs of the
Buffalo are matched to the outputs of ICS clock
synthesizers. Consult ICS for applications support.
QB1
QB2
QB3
QB4
QB5
QB7
QB6
INB
OE (all outputs)
QA0
QA1
QA2
QA3
QA4
QA5
QA7
QA6
INA
VDD
GND
VDD
VDDA
VDDB
MK74CB218
Dual 1 to 8 BuffaloTM Clock Driver
MDS 74CB218 A
2
Revision 021600 Printed 11/16/00
IntegratedCircuit Systems, Inc. 525 Race Street San Jose CA 95126(408) 295-9800tel www.icst.com
P R E L I M I N A R Y I N F O R M A T I O N
Number
Name
Type
Description
1
INA
I
Clock input for eight A outputs.
2, 3, 4
QA0, QA1, QA2
O
Clock A outputs.
5, 6
VDDA
P
Power supply for QA outputs. Connect to a voltage from 2.5V to 5V. Cannot exceed VDD.
7, 8
QA3, QA4
O
Clock A outputs.
9, 10
GND
P
Connect to ground.
11, 12, 13 QA5, QA6, QA7
O
Clock A outputs.
14
OE
I
Output Enable. Tri-states all clock outputs when this input is low. Internal pull-up to VDD.
15
VDD
P
Power supply for inputs.
16, 17, 18 QB7, QB6, QB5
O
Clock B outputs.
19, 20
GND
P
Connect to ground.
21, 22
QB4, QB3
O
Clock B outputs.
23, 24
VDDB
P
Power supply for QB outputs. Connect to a voltage from 2.5V to 5V. Cannot exceed VDD.
25, 26, 27 QB2, QB1, QB0
O
Clock B outputs.
28
INB
I
Clock input for eight B outputs.
Pin Descriptions
Type: I = Input, O = output, P = power supply connection
Pin Assignment
1
8
9
2
3
4
5
6
7
10
11
12
13
14
QA0
QA1
QA2
QA3
QA4
QA5
QA7
QA6
INA
GND
GND
OE
VDDA
VDDA
QB0
QB1
QB2
QB3
QB4
QB5
QB7
QB6
INB
GND
GND
VDD
VDDB
VDDB
16
15
17
18
19
20
21
22
23
24
25
28
27
26
Suggested Layout
A
G
G
B
For simplicity, series terminating resistors are not shown
for the outputs, but should be placed as close to the device
as possible. It is most critical to have the 0.01F
decoupling capacitors closest.
V = connect to VDD
= connect to low
inductance ground plane
G
0.01F
0.01F
A = connect to VDDA
B = connect to VDDB
G
0.01F
V
MK74CB218
Dual 1 to 8 BuffaloTM Clock Driver
MDS 74CB218 A
3
Revision 021600 Printed 11/16/00
IntegratedCircuit Systems, Inc. 525 Race Street San Jose CA 95126(408) 295-9800tel www.icst.com
P R E L I M I N A R Y I N F O R M A T I O N
Parameter
Conditions
Minimum
Typical
Maximum
Units
ABSOLUTE MAXIMUM RATINGS (Note 1)
ABSOLUTE MAXIMUM RATINGS (Note 1)
Supply Voltage, VDD
Referenced to GND
7
V
Inputs
Referenced to GND
0.5
VDD+0.5
V
Clock Outputs
Referenced to GND
0.5
VDD+0.5
V
Ambient Operating Temperature
0
70
C
Soldering Temperature
Max of 20 seconds
260
C
Storage Temperature
-65
150
C
DC CHARACTERISTICS (VDD = 3.3 V unless noted)
DC CHARACTERISTICS (VDD = 3.3 V unless noted)
Operating Voltage, VDD
3.0
3.3
5.5
V
Operating Voltage, VDDA or VDDB
2.375
VDD
V
Input High Voltage, VIH (INA, INB pins)
VDD-1.0
VDD/2
V
Input Low Voltage, VIL (INA, INB pins)
VDD/2
1.0
V
Input High Voltage, VIH (OE pin)
2.0
V
Input Low Voltage, VIL (OE pin)
0.8
V
Output High Voltage, 3.3V and 5V
IOH=-12mA
VDD-0.4
V
Output High Voltage, 3.3V and 5V
IOH=-25mA
2.4
V
Output Low Voltage, 3.3V and 5V
IOL=25mA
0.8
V
Output High Voltage, 2.5V
IOH=-16mA
2
V
Output Low Voltage, 2.5V
IOL=16mA
0.5
V
Operating Supply Current, IDD, at 100 MHz
No Load
55
mA
Output Impedance
14
Short Circuit Current
Each output
100
mA
On-Chip Pull-up Resistor
OE
250
k
Input Capacitance
7
pF
AC CHARACTERISTICS (VDD = 3.3 V unless noted)
AC CHARACTERISTICS (VDD = 3.3 V unless noted)
Input Clock Frequency
Note 4
0
200
MHz
Propagation Delay with load=15pF
1.4
3
ns
Output Clock Rise Time
0.8 to 2.0V
2
ns
Output Clock Fall Time
2.0 to 0.8V
2
ns
Output Clock Rising Edge Skew
At VDD/2. Note 2
100
250
ps
Output Clock A to B Skew
At VDD/2. Note 3
100
250
ps
Output Enable Time, OE high to output on
20
ns
Output Disable Time, OE low to tri-state
20
ns
Electrical Specifications
Notes:
1. Stresses beyond those listed under Absolute Maximum Ratings could cause permanent damage to the device. Prolonged exposure
to levels above the operating limits but below the Absolute Maximums may affect device reliability.
2. Between any two A outputs, or any two B outputs, with equal loading.
3. Between any clock A output and any clock B output with INA connected to INB, and equal loading.
4. See discussion and graph of speed versus load.
MK74CB218
Dual 1 to 8 BuffaloTM Clock Driver
MDS 74CB218 A
4
Revision 021600 Printed 11/16/00
IntegratedCircuit Systems, Inc. 525 Race Street San Jose CA 95126(408) 295-9800tel www.icst.com
P R E L I M I N A R Y I N F O R M A T I O N
300
250
200
150
100
50
0
80
60
40
20
0
Maximum Speed
The maximum speed at which the chip can operate is limited by power dissipation in the package. Graph 1
shows the operating frequency plotted against load capacitance per pin for a die temperature of 125C.
This is at VDD = VDDA = VDDB = 3.3 V, 70C and with 33
series termination resistors. The
termination resistors are essential because they allow a large proportion of the total power to be dissipated
outside the package. Reducing or eliminating the series termination will cause an increase in die
temperature. It is not recommended to operate the chip at die temperatures greater than 125C. Also note
that the load capacitance per pin must include PC board parasitics such as trace capacitance.
If not all outputs of the chip are used, it is possible to operate the chip faster with larger loads. Consult ICS
for your specific requirement.
Do not operate in this area .
Load Capacitance/per pin (pF)
Graph 1
MK74CB218
Maximum Speed with all VDDs at 3.3V
MK74CB218
Dual 1 to 8 BuffaloTM Clock Driver
MDS 74CB218 A
5
Revision 021600 Printed 11/16/00
IntegratedCircuit Systems, Inc. 525 Race Street San Jose CA 95126(408) 295-9800tel www.icst.com
P R E L I M I N A R Y I N F O R M A T I O N
Ordering Information
While the information presented herein has been checked for both accuracy and reliability, ICS Incorporated assumes no responsibility for either its use or for the infringement of
any patents or other rights of third parties, which would result from its use. No other circuits, patents, or licenses are implied. This product is intended for use in normal
commercial applications. Any other applications such as those requiring extended temperature range, high reliability, or other extraordinary environmental requirements are not
recommended without additional processing by ICS. ICS reserves the right to change any circuitry or specifications without notice. ICS does not authorize or warrant any ICS
product for use in life support devices or critical medical instruments.
Buffalo is a trademark of ICS Incorporated
Part/Order Number
Marking
Package
Temperature
MK74CB218R
MK74CB218R
28 pin SSOP
0-70 C
MK74CB218RTR
MK74CB218R
Add Tape & Reel
0-70 C
b
D
E1
E
e
A1
c
A
L
INDEX
AREA
1
2
Package Outline and Package Dimensions
(
For current dimensional specifications, see JEDEC Publication No. 95.)
28 pin SSOP
Inches
Inches
Millimeters
Millimeters
Symbol
Min
Max
Min
Max
A
0.053
0.069
1.35
1.75
A1
0.004
0.010
0.10
0.25
b
0.008
0.012
0.20
0.30
c
0.007
0.010
0.18
0.25
D
0.337
0.344
8.55
8.75
e .025 BSC
.025 BSC
0.635 BSC
0.635 BSC
E
0.228
0.244
5.80
6.20
E1
0.150
0.157
3.80
4.00
L
0.016
0.050
0.40
1.27
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