mk1491-14 Integrated Device Technology, mk1491-14 Datasheet - Page 4
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mk1491-14
Manufacturer Part Number
mk1491-14
Description
Opti Acpi Firestar Clock Source
Manufacturer
Integrated Device Technology
Datasheet
1.MK1491-14.pdf
(4 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
MDS 1491-14 B
Integrated Circuit Systems, Inc. • 525 Race Street • San Jose •CA •95126 • (408)295-9800tel • www.icst.com
External Components
The MK1491 requires some inexpensive external components for proper operation. Decoupling capacitors of 0.1µF should be connected on
each VDD pin to ground, as close to the MK1491 as possible. A series termination resistor of 33
discussion on page 4 for other external resistors required for proper I/O operation. The 14.318 MHz oscillator has internal caps that provide
the proper load for a parallel resonant crystal with C L =18pF. For tuning with other values of C L , the formula 2•(C L -18) gives the value of each
capacitor that should be connected between X1 and ground and X2 and ground.
I/O Structure
The MK1491 provides more functionality in a 28 pin package by using a
unique I/O technique. The device checks the status of all I/O pins during
power-up. This status (pulled high or low) then determines the frequency
selections and power down modes (see the tables on page 2). Within 10ms
after power up, the inputs change to outputs and the clocks start up. In the
diagrams to the right, the 33
termination resistors. The 10k
zero. Internal pull-up resistors are present on all inputs to generate a logic
one when an external pull-down resistor is not connected.
Package Outline and Package Dimensions
Ordering Information
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.
Pentium is a trademark of Intel Corporation
Q
Part/Order Number
MK1491E-14RTR
MK1491E-14R
e
D
b
c
E
h x 45°
resistor pulls low to generate a logic
H
MK1491E-14R
MK1491E-14R
resistors are the normal output
Marking
A
OPTi ACPI Firestar Clock Source
Low EMI Feature
Yes
Yes
4
28 pin SSOP
Symbol
For select
= 0 (low)
For select
= 1 (high)
D
H
Q
A
E
h
Add Tape & Reel
b
c
e
28 pin SSOP
0.061
0.008
0.007
0.385
0.150
0.230
0.004
Package
Min
may be used for each clock output. See the
.025 BSC
.025 BSC
Inches
Inches
0.068
0.012
0.010
0.400
0.160
0.245
0.016
Max
0.01
I/O
I/O
0.203
0.190
9.780 10.160
3.810
5.840
0.127
Min
1.55
Millimeters
Millimeters
0.635 BSC
0.635 BSC
MK1491-14
10k
Temperature
33
33
0-70°C
Revision 061801
0.305
0.254
4.064
6.223
0.410
0.254
Max
1.73
-
to load
to load