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Details, datasheet, quote on part number:ICS650-40A
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Datasheet text preview:
ICS650-40A
ETHERNET SWITCH CLOCK SOURCE
Description
The ICS650-40A is a clock chip designed for use as a core clock in Ethernet Switch applications. Using ICS' patented Phase-Locked Loop (PLL) techniques, the device takes a 25 MHz crystal input and produces various output clock frequencies as listed in Output Select Table.
Features
· · · · · ·
Packaged in 16-pin TSSOP Operating voltage of 3.3 V Low power consumption Input frequency of 25 MHz Low long-term jitter Separate supply voltage for clock outputs (2.5 / 3.3 V clock outputs)
Block Diagram
VDD 2 VDDOA VDDOB
S1:S0
2
Control Logic CLKB Phase Lock Loop CLKA CLKA
X1/ICLK 25 MHz crystal or clock X2
Clock Buffer/ Cryst al Oscillator 4 GND
Optional tuning crystal capacitors
OE
MDS 650-40A B Integrated Circuit Systems
1
525 Race Stre e t , San Jo s e , CA 9 5 1 2 6
Revision 071504 te l (40 8 ) 2 9 7 - 1 2 0 1
w w w. i c s t . c o m
ICS650-40A ETHERNET SWITCH CLOCK SOURCE
Pin Assignment
X1/ICLK VDD GNDA VDDOA CLKA CLKA GNDA S1 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 X2 VDD OE GND VDDOB CLKB GNDB S0
Output Select Table (MHz)
S1 0 0 1 1 S0 0 1 0 1 CLKA (MHz) 127 133 157 189 CLKA (MHz) 127 133 157 189 CLKB (MHz) 157 189 127 133
16-pin (173 mil) TSSOP
Pin Descriptions
Pin Number
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Pin Name
X1/ICLK VDD GNDA VDDOA CLKA CLKA GNDA S1 S0 GNDB CLKB VDDOB GND OE VDD X2
Pin Type
Input Power Power Power Connect to +3.3 V. Connect to ground.
Pin Description
Crystal or clock input. Connect to a 25 MHz crystal or single ended clock.
Connect to +2.5 V or +3.3 V. For CLKA outputs only.
Output Clock A output with weak pull-down resistor. Output Clock A output with weak pull-down resistor. Power Input Input Power Power Power Input Power Connect to ground. Select pin 1. No internal pull-up resistor. Select pin 0. No internal pull-up resistor. Connect to ground. Connect to +2.5 V or 3.3 V. For clock output B only. Connect to ground. Output enable tri-states outputs and device is not shut down. Internal pull-up resistor. Connect to +3.3 V.
Output Clock B output with weak pull-down resistor.
Output Crystal connection. Leave unconnected for clock input.
MDS 650-40A B I n t e g r a t e d Circuit Systems
2
525 Ra c e Street, San Jose, CA 9512 6
Revision 071504 tel (4 0 8 ) 297-1 2 0 1
w w w. i c s t . c o m
ICS650-40A ETHERNET SWITCH CLOCK SOURCE
External Components
A minimum number of external components are required for proper operation. Decoupling capacitors of 0.01 µF should be connected between VDD and GND pairs. The capacitors should be placed between pins VDD and GND, VDDOA and GND, and VDDOB and GND as close to the device as possible. A 33 series terminating resistor should be used on each clock output if the trace is longer than 1 inch. A 25 MHz fundamental mode parallel resonant crystal should be used with CL=18 pF. On chip capacitors. On Chip capacitors are used for a 18 pF load crystal. Small, 2-3 pF trimming capacitors are used from pins X1 to ground and X2 to ground to optimize the initial accuracy.
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the ICS650-40A. 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
Supply Voltage, VDD All Inputs and Outputs Ambient Operating Temperature Storage Temperature Junction Temperature Soldering Temperature 7V
Rating
-0.5 V to VDD+0.5 V 0 to +70°C -65 to +150°C 125°C 260°C
Recommended Operation Conditions
Parameter
Ambient Operating Temperature Power Supply Voltage (measured in respect to GND)
Min.
0 +3.15
Typ.
Max.
+70 +3.45
Units
°C V
MDS 650-40A B I n t e g r a t e d Circuit Systems
3
525 Ra c e Street, San Jose, CA 9512 6
Revision 071504 tel (4 0 8 ) 297-1 2 0 1
w w w. i c s t . c o m
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