MDS 409 C

3

Revision 111005

www.icst.com

ICS409

load capacitance, each crystal capacitor would be 18

pF [(15-6) x 2] = 18.

PCB Layout Recommendations

For optimum device performance and lowest output

phase noise, the following guidelines should be

observed.

1) The 0.01µF decoupling capacitor should be mounted

on the component side of the board as close to the

VDD pin as possible. No vias should be used between

decoupling capacitor and VDD pin. The PCB trace to

VDD pin should be kept as short as possible, as should

the PCB trace to the ground via.

2) The external crystal should be mounted just next to

the device with short traces. The X1 and X2 traces

should not be routed next to each other with minimum

spaces, instead they should be separated and away

from other traces.

3) To minimize EMI the 33

Ω series termination resistor,

if needed, should be placed close to the clock output.

4) An optimum layout is one with all components on the

same side of the board, minimizing vias through other

signal layers. Other signal traces should be routed

away from the ICS409. This includes signal traces just

underneath the device, or on layers adjacent to the

ground plane layer used by the device.

Selection of 40M/80M Clock

The 40/80M output clock is selected by a soft pull-up or

pull-down on 40/80M pin (pin 5). A rising edge on

OE/LAT latches in the high or low level on pin 5 which

starts the appropriate frequency.

Absolute Maximum Ratings

Stresses above the ratings listed below can cause permanent damage to the ICS409. 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.

Recommended Operation Conditions

DC Electrical CharacteristicsDC Electrical Characteristics (continued)

Item

Rating

Supply Voltage, VDD

7 V

All Inputs and Outputs

-0.5 V to VDD+0.5 V

Ambient Operating Temperature

0 to +70

°C

Storage Temperature

-65 to +150

°C

Junction Temperature

175

°C

Soldering Temperature

260

°C

Parameter

Min.

Typ.

Max.

Units

Ambient Operating Temperature

0

–

+70

°C

Power Supply Voltage (measured in respect to GND)

+3.00

+3.60

V