Datasheet MK74CB214R Datasheet (ICST)

Page 1
MK74CB214
Dual 1 to 7 Buffalo™ Clock Driver
Description
The MK74CB214 Buffalo™ is a monolithic CMOS high speed clock driver which is ideal for Pentium™, 486, and RISC processor systems. It consists of two identical single input to seven low­skew output, non-inverting clock drivers. When combined with MicroClock’s MK14xx series of low jitter clock synthesizers, the two chips form an unequaled high performance clocking scheme for new processors. This is the only solution on the market that meets Intel’s specs for skew and jitter. Many new Pentium systems require up to seven outputs each of two low-skew clocks. This monolithic solution eliminates any concern for part-to-part skew matching. The MK74CB214 is packaged in the tiny 20 pin SSOP, which uses the same board space as the narrow 14 pin SOIC. An added feature of the chip is the ability to produce both 3.3V and 5V amplitude clocks by connecting different voltages to VDDA and VDDB. See MAN03 for dual voltage operation.
Features
• Tiny 20 pin SSOP (150 mil) package
• Dual one input to seven output clock drivers
• Outputs are skew matched to within 250ps
• A outputs and B outputs matched to 500ps
• Each set of seven clock drivers can run from different supply voltages, making it possible to have 3.3V and 5V amplitude clock outputs from the same chip
• Clock speeds up to 66.67 MHz
Family of MicroClock Parts
The MK74CB214 Buffalo™ is designed to be used with MicroClock’s clock synthesizer devices, which will produce the CPU, memory, and local bus clocks. The inputs of the Buffalo are matched to the outputs of MicroClock clock synthesizers. Consult MicroClock for applications support.
Block Diagram
INA QA0
QA1 QA2
QA3 QA4
QA5 QA6
VDDA
GNDA
VDDB
INB
QB0 QB1
QB2 QB3
QB4 QB5
QB6
GNDB
MDS 74CB214 B 1 Revision 051396 Printed 11/16/00
MicroClock Incorporated•1171 North Fourth St.•San Jose•CA•95112•(408)295-9800tel•(408)295-9818fax
Page 2
MK74CB214
Dual 1 to 7 Buffalo™ Clock Driver
Pin Assignment
INA
QA0 QA1
VDDA
QA2 QA3
GNDA
QA4 QA5 QA6
1 2
3 4
5 6
7 8 9
10
20 19 18
17 16 15
14 13 12 11
INB QB0
QB1 VDDB
QB2 QB3 GNDB QB4 QB5 QB6
Suggested Layout
V
0.1µF
G
For simplicity, terminating resistors (if needed) 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 GNDG
V
0.1µF
G
Pin Descriptions
Number Name Type Description
1 INA I Clock input for seven A outputs.
2, 3 QA0, QA1 O Clock A outputs.
4 VDDA P Power supply for seven A buffers. Connect to +3.3V or +5V. Clock amplitude will match.
5, 6 QA2, QA3 O Clock A outputs.
7 GNDA P Connect to ground.
8, 9, 10 QA4, QA5, QA6 O Clock A outputs.
11, 12, 13 QB6, QB5, QB4 O Clock B outputs.
14 GNDB P Connect to ground.
15, 16 QB3, QB2 O Clock B outputs.
17 VDDB P Power supply for seven B buffers. Connect to +3.3V or +5V. Clock amplitude will match.
18, 19 QB1, QB0 O Clock B outputs.
20 INB I Clock input for sevent B outputs.
Type: I = Input, O = output, P = power supply connection
MDS 74CB214 B 2 Revision 051396 Printed 11/16/00
MicroClock Incorporated•1171 North Fourth St.•San Jose•CA•95112•(408)295-9800tel•(408)295-9818fax
Page 3
MK74CB214
ABSOLUTE MAXIMUM RATINGS (Note 1)
DC CHARACTERISTICS (VDD = 5V unless noted)
AC CHARACTERISTICS (VDD = 5V unless noted)
Dual 1 to 7 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 10 seconds 260 °C Storage Temperature -65 150 °C
Operating Voltage, VDD 3.0 5.5 V Input High Voltage, VIH (INA, INB pins) VDD-1 VDD/2 V Input Low Voltage, VIL (INA, INB pins) VDD/2 1 V Output High Voltage, 3.3V and 5V IOH=-8mA VDD-0.4 V Output High Voltage, 3.3V and 5V IOH=-12mA 2.4 V Output Low Voltage, 3.3V and 5V IOL=12mA 0.8 V Operating Supply Current, IDD, at 66.6MHz No Load 20 mA Short Circuit Current Each output ±70 mA Short Circuit Current at 3.3V Each output ±35 mA Input Capacitance 7 pF
Input Clock Frequency 67 MHz Propagation Delay with load=10pF 2 3.5 5 ns Propagation Delay with load=10pF At VDD=3.3V 2.5 4.5 6.5 ns Output Clock Rise Time, 3.3V and 5V 0.8 to 2.0V 1.5 ns Output Clock Fall Time, 3.3V and 5V 2.0 to 0.8V 1.5 ns Output Clock Rising Edge Skew, 3.3V and 5V At VDD/2. Note 2 50 250 ps Output Clock A to B Skew, 3.3V and 5V At VDD/2. Note 3 100 500 ps Maximum load per output pin At 66.66 MHz 25 pF Maximum load per side of 7 outputs Note 4 105 pF
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. With VDDA=VDDB and equal loading. Combined with the 250ps uncertainty of MicroClock’s Clock Synthesizers, this adds to a 750ps total.
4. This is the load sum of all A outputs, or all B outputs, at 66.66MHz. The formula for per side load is CL (F) =
-3
7 x 10 f (in Hz)
MDS 74CB214 B 3 Revision 051396 Printed 11/16/00
MicroClock Incorporated•1171 North Fourth St.•San Jose•CA•95112•(408)295-9800tel•(408)295-9818fax
Page 4
MK74CB214
Inches
Millimeters
Dual 1 to 7 Buffalo™ Clock Driver
Package Outline and Package Dimensions
E H
h x 45°
D
Q
e
c
b
20 pin SSOP
Symbol Min Max Min Max
A 0.061 0.068 1.55 1.73 b 0.008 0.012 0.203 0.305
c 0.007 0.010 0.191 0.254
D 0.337 0.344 8.560 8.740
E 0.150 0.160 3.810 4.064
H 0.230 0.245 5.842 6.223
e
h 0.016 0.406
Q 0.005 0.01 0.127 0.254
A
Ordering Information
Part/Order Number Marking Package Temperature
MK74CB214R 74CB214R 20 pin SSOP 0-70°C
MK74CB214RTR 74CB214R Add Tape & Reel 0-70°C
While the information presented herein has been checked for both accuracy and reliability, MicroClock 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 MicroClock. MicroClock reserves the right to change any circuitry or specifications without notice. MicroClock does not authorize or warrant any MicroClock product for use in life support devices or critical medical instruments.
Buffalo is a trademark of MicroClock Incorporated Pentium is a trademark of Intel Corporation
MDS 74CB214 B 4 Revision 051396 Printed 11/16/00
MicroClock Incorporated•1171 North Fourth St.•San Jose•CA•95112•(408)295-9800tel•(408)295-9818fax
Loading...