Page 1
MK74CB115
1 to 16 Buffalo™ Clock Driver
Description
The MK74CB115 Buffalo™ is a monolithic
CMOS high speed clock driver. It consists of a
single input to sixteen low-skew output, noninverting clock drivers. The chip is capable of
driving 16 CMOS loads up to 200 MHz with a
maximum of 250 ps output to output skew. The
MK74CB115 is packaged in the tiny 28 pin SSOP,
which uses the same board space as the narrow 16
pin SOIC.
Family of ICS Parts
The MK74CB115 Buffalo™ 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.
Block Diagram
OE2
VDD
4
Features
• Tiny 28 pin SSOP (150 mil) package
• One input to sixteen output clock drivers
• Outputs are skew matched to within 250 ps
• 3.3V±10% or 5V±10% supply voltage
• 3 Output Enables allow configuration as 1 to 4,
1 to 6, 1 to 10, 1 to 12 or 1 to 16 buffer
• Clock speeds up to 200 MHz
IN
Q0
Q1
Q2
Q3
Q4
Q5
Q6
Q7
4
OE1
MDS 74CB115 D 1 Revision 020800 Printed 11/16/00
Integrated Circuit Systems, Inc. • 525 Race St. • San Jose • CA • 95126 • (408) 295-9800tel • www.icst.com
GND
OE0
Q15
Q14
Q13
Q12
Q11
Q10
Q9
Q8
Page 2
MK74CB115
1 to 16 Buffalo™ Clock Driver
Pin Assignment
1
OE1
2
Q0
Q1
3
Q2
4
5
VDD
VDD
6
Q3
7
8
Q4
Q5
Q6
Q7
IN
9
10
11
12
13
14
GND
GND
28
27
26
25
24
23
22
21
20
19
18
17
16
15
OE2
Q15
Q14
Q13
VDD
VDD
Q12
Q11
GND
GND
Q10
Q9
Q8
OE0
Suggested Layout
V
0.1µF
G
For simplicity, series terminating resistors (required) are
not shown for the outputs, but should be placed as close to
the device as possible. It is most critical to have the 0.1µF
decoupling capacitors closest.
= connect to VDD
V
= connect to GND
G
G
V
0.1µF
Pin Descriptions
Number Name Type Description
1 OE1 I Output Enable. Tri-states Q2 to Q7 clock outputs when this input is low. Internal pull-up.
2, 3 Q0, Q1 O Clock outputs.
4, 7, 8 Q2, Q3, Q4 O Clock outputs.
5, 6 VDD P Power supply. Connect to +3.3 V or 5 V.
9, 10 GND P Connect to ground.
11, 12, 13 Q5, Q6, Q7 O Clock outputs.
14 IN I Clock input for 16 buffers.
15 OE0 I Output Enable. Tri-states Q8 to Q13 clock outputs when this input is low. Internal pull-up.
16, 17, 18 Q8, Q9, Q10 O Clock outputs.
19, 20 GND P Connect to ground.
21, 22, 25 Q11, Q12, Q13 O Clock outputs.
23, 24 VDD P Power supply. Connect to +3.3 V or 5 V.
26, 27 Q14, Q15 O Clock outputs.
28
Type: I = Input, O = output, P = power supply connection
OE2 I Output Enable. Tri-states Q0, Q1, Q15 and Q14 clock outputs when this input is low.
Internal pull-up.
MDS 74CB115 D 2 Revision 020800 Printed 11/16/00
Integrated Circuit Systems, Inc. • 525 Race St. • San Jose • CA • 95126 • (408) 295-9800tel • www.icst.com
Page 3
MK74CB115
ABSOLUTE MAXIMUM RATINGS (Note 1)
DC CHARACTERISTICS (VDD = 3.3 V unless noted)
AC CHARACTERISTICS (VDD = 3.3 V unless noted)
1 to 16 Buffalo™ Clock Driver
Electrical Specifications
Parameter Conditions Minimum Typical Maximum Units
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
Operating Voltage, VDD 3.0 3.3 5.5 V
Input High Voltage, VIH (IN pin) Input clock (VDD/2)+1 VDD/2 V
Input Low Voltage, VIL (IN pin) Input clock VDD/2 (VDD/2)-1 V
Input High Voltage, VIH (OE pins) 2.0 V
Input Low Voltage, VIL (OE pins) 0.8 V
Output High Voltage, 3.3V IOH=-8mA VDD-0.4 V
Output High Voltage, 3.3V IOH=-12mA 2.4 V
Output Low Voltage, 3.3V IOL=12mA 0.8 V
Operating Supply Current, IDD, at 100 MHz No Load 55 mA
Output Impedance 14 Ω
Short Circuit Current, 3.3V Each output ±50 mA
On-Chip Pull-up Resistor OE0, OE1, OE2 250 kΩ
Input Capacitance 5 pF
Input Clock Frequency with load = 8 pF Note 4, 5 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 Enable Time, OE high to output on 20 ns
Output Disable Time, OE low to tri-state 20 ns
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 outputs, with equal loading.
3. At VDD = 3.3 V, 70°C, series termination of 33 Ω per pin , 8 pF load per pin.
4. See discussion and graph of speed versus load, Graph 1 on following page.
MDS 74CB115 D 3 Revision 020800 Printed 11/16/00
Integrated Circuit Systems, Inc. • 525 Race St. • San Jose • CA • 95126 • (408) 295-9800tel • www.icst.com
Page 4
MK74CB115
1 to 16 Buffalo™ Clock Driver
Maximum Speed/Application Notes
The maximum speed at which the chip can operate is limited by power dissipation of the package. Graph 1
shows the operating frequency plotted against load capacitance per pin for a die temperature of 125°C. This is
at VDD = 3.3 V, 70°C and with 33 Ω series termination resistor. 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 temperature greater than 125°C. Also note that the load capacitance per pin must include PC
board parasitics such as trace capacitance. ICS has other buffers specified to 250 MHz with heavier loads.
If not all outputs of the chip are used, it is possible to operate the chip faster with larger loads. Unused outputs
should be left unconnected. Consult ICS for your specific requirement.
300
250
200
Do not operate in this area .
150
100
50
0
Load Capacitance/per pin (pF), all 16 outputs loaded
Graph 1
MK74CB115
Maximum Speed at 3.3 V
806040200
MDS 74CB115 D 4 Revision 020800 Printed 11/16/00
Integrated Circuit Systems, Inc. • 525 Race St. • San Jose • CA • 95126 • (408) 295-9800tel • www.icst.com
Page 5
1 to 16 Buffalo™ Clock Driver
Inches
Millimeters
AREA
Package Outline and Package Dimensions
(For current dimensional specifications, see JEDEC Publication No. 95.)
28 pin SSOP
Symbol Min Max Min Max
A 0.053 0.069 1.35 1.75
E1 E
INDEX
1 2
D
A1 0.004 0.010 0.102 0.254
b 0.008 0.012 0.203 0.305
c 0.007 0.010 0.191 0.254
D 0.386 0.394 9.804 10.008
e
E 0.228 0.244 5.791 6.198
E1 0.150 0.157 3.810 3.988
L 0.016 0.050 0.406 1.270
MK74CB115
A1 c
A
e
b
L
Ordering Information
Part/Order Number Marking Package Temperature
MK74CB115R MK74CB115R 28 pin SSOP 0-70°C
MK74CB115RTR MK74CB115R Add Tape & Reel 0-70°C
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
MDS 74CB115 D 5 Revision 020800 Printed 11/16/00
Integrated Circuit Systems, Inc. • 525 Race St. • San Jose • CA • 95126 • (408) 295-9800tel • www.icst.com
Loading...