MDS 613 C

3

Revision 111204

Integrated Circuit Systems, Inc.

ICS613

External Component Selection

The ICS613 requires a minimum number of external

components for proper operation.

Decoupling Capacitors

Decoupling capacitors of 0.01

µF should be connected

between VDD and GND pairs on pins 4 and 5, pins 6

and 8, pins 11 and 9, and pins 13 and 14 as close to

the ICS613 as possible. For optimum device

performance, the decoupling capacitors should be

mounted on the component side of the PCB. Avoid the

use of vias in the decoupling circuit.

Series Termination Resistor

When the PCB traces between the clock outputs and

the loads are over 1 inch, series termination should be

used. To series terminate a 50

Ω trace (a commonly

used trace impedance) place a 33

Ω resistor in series

with the clock line, as close to the clock output pin as

possible. The nominal impedance of the clock output is

20

Ω.

Crystal Tuning Load Capacitors

The device crystal connections should include pads for

small capacitors from X1 to ground and from X2 to

ground. These capacitors are used to adjust the stray

capacitance of the board to match the nominally

required crystal load capacitance. Because load

capacitance can only be increased in this trimming

process, it is important to keep stray capacitance to a

minimum by using very short PCB traces (and no vias)

been the crystal and device. Crystal capacitors must be

connected from each of the pins X1 and X2 to ground.

The value (in pF) of these crystal caps should equal

capacitance in pF.

Example: For a crystal with a 16 pF load capacitance,

each crystal capacitor would be 20 pF [(16-6) x 2] = 20.

Reducing Jitter and Phase Noise

For applications that only require one output, jitter and

phase noise can be reduced by tying the unused

VDDO to ground. This will stop the output clock low

which will result in less switching noise on the active

output.

Absolute Maximum Ratings

Stresses above the ratings listed below can cause permanent damage to the ICS613. 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.

Item

Rating

Supply Voltage, VDD

7V

All Inputs and Outputs

-0.5V to VDD+0.5V

Ambient Operating Temperature

0 to +70

°C

Storage Temperature

-65 to +150

°C

Soldering Temperature

260

°C