mk2049-34 Integrated Device Technology, mk2049-34 Datasheet - Page 6

• Manufacturer Part Number: mk2049-34
• Description: 3.3 Volt Communications Clock Vcxo Pll
• Manufacturer: Integrated Device Technology

External Component Selection
The MK2049-34 requires a minimum number of external components for proper operation. Decoupling capacitors of 0.01µF
must be connected between VDD and GND pins close to the chip (especially pins 4 and 7, 15 and 17), and 33Ω series
terminating resistors should be used on clock outputs with traces longer than one inch (assuming 50Ω traces). The
selection of additional external components is described in the following sections.
Loop Filter
Information on how to configure the external loop filter, connected between pins CAP1 and CAP2, can be found at
http://www.icst.com/products/telecom/telecom.htm
Crystal Operation
The MK2049-34 operates by phase locking the input signal to a VCXO which consists of the recommended pullable VCXO
crystals and the integrated VCXO oscillator circuit on the MK2049. To achieve the best performance and reliability, the
layout guidelines shown on the previous page should be closely followed.
The frequency of oscillation of a quartz crystal is determined by its cut and by the load capacitors connected to it. The
MK2049 has variable load capacitors on-chip which “pull” or change the frequency of the crystal. External stray capacitance
must be kept to a minimum to ensure maximum pullability of the crystal. To achieve this, the layout should use short traces
between the MK2049 and the crystal.
For the VCXO to operate correctly, a pullable crystal must be used. For more information, including a list of approved
crystals, please refer to application note MAN05 (http://www.icst.com/products/summary/man05.htm).
Absolute Maximum Ratings
Recommended Operation Conditions
IDT™ / ICS™ 3.3 VOLT COMMUNICATIONS CLOCK VCXO PLL
MK2049-34
3.3 VOLT COMMUNICATIONS CLOCK VCXO PLL
Stresses above the ratings listed below can cause permanent damage to the MK2049-34. These ratings, which are
standard values for ICS commercially rated parts, are stress ratings only. Functional operation of the device at
these or any other conditions above those indicated in the operational sections of the specifications is not implied.
Exposure to absolute maximum rating conditions for extended periods can affect product reliability. Electrical
parameters are guaranteed only over the recommended operating temperature range.
Supply Voltage, VDD
All Inputs and Outputs
Ambient Operating Temperature
Storage Temperature
Junction Temperature
Soldering Temperature
Parameter
Ambient Operating Temperature
Power Supply Voltage (measured in respect to GND)
Item
and http://www.icst.com/PDF/MK2049-3x%20Addendum.pdf.
6
+3.15
Min.
-40
7 V
-0.5 V to VDD+0.5 V
-40 to +85°C
-65 to +150°C
175°C
250°C
Typ.
+3.3
Rating
+3.45
Max.
+85
VCXO AND SYNTHESIZER
MK2049-34
Units
°C
V
REV F 102203