ICS291
TRIPLE PLL FIELD PROG. SPREAD SPECTRUM CLOCK SYNTHESIZER
EPROM CLOCK SYNTHESIZER
Pin Assignment
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
GND
S0
S1
VDD
VDDO1
CLK1
CLK2
CLK3
GND
X1/ICLK
S2
VDD
PDTS
GND
CLK6
CLK5
CLK4
VDDO2
VDD
X2
20 pin (173 mil) TSSOP
Pin Descriptions
Pin
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Pin
Name
GND
S0
S1
VDD
VDDO1
CLK1
CLK2
CLK3
GND
X1/ICLK
X2
VDD
VDDO2
CLK4
CLK5
CLK6
GND
PDTS
VDD
S2
Pin
Type
Power
Input
Input
Power
Power
Output
Output
Output
Power
XI
XO
Power
Power
Output
Output
Output
Power
Input
Power
Input
Connect to ground.
Pin Description
Select pin 0. Internal pull-up resistor.
Select pin 1. Internal pull-up resistor.
Connect to +3.3 V.
Power supply for outputs CLK1-CLK3.
Output clock 1. Weak internal pull-down when tri-state.
Output clock 2. Weak internal pull-down when tri-state.
Output clock 3. Weak internal pull-down when tri-state.
Connect to ground.
Crystal input. Connect this pin to a crystal or external input clock.
Crystal Output. Connect this pin to a crystal. Float for clock input.
Connect to +3.3 V.
Power supply for outputs CLK4-CLK6.
Output clock 4. Weak internal pull-down when tri-state.
Output clock 5. Weak internal pull-down when tri-state.
Output clock 6. Weak internal pull-down when tri-state.
Connect to ground.
Power-down tri-state. Powers down entire chip and tri-states clock outputs
when low. Internal pull-up resistor.
Connect to +3.3 V.
Select pin 2. Internal pull-up resistor.
IDT™ / ICS™
TRIPLE PLL FIELD PROG. SPREAD SPECTRUM CLOCK SYNTHESIZER 2
ICS291
REV D 061306