DATASHEET
PECL TO CMOS CONVERTER
Description
The ICS508 is the most cost effective way to generate
a high quality, high frequency CMOS clock output from
a PECL clock input.
The ICS508 has separate VDD supplies for the PECL
input buffer and the output buffer, allowing different
voltages to be used. For example, the input clock could
use a 3.3 V supply while the output operates from 2.5V.
The device has an Output Enable pin that tri-states the
clock output when the OE pin is taken low.
The ICS508 is a member of IDT’s
family.
ClockBlocks
TM
ICS508
Features
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Packaged in 8 pin SOIC (Pb-free) or die
Separate VDD supplies allow voltage translation
Clock frequency of 0 - 250 MHz
Duty cycle of 45/55
Operating voltages of 2.375 to 5.5V
Tri-state output for board level testing
24mA output drive capability
Industrial temperature version available
Advanced, low power, sub-micron CMOS process
Block Diagram
VDDP
VDDC
P E C LIN
P E C LIN
O utput
B uffer
C LK
GND
OE
GND
IDT™ / ICS™
PECL TO CMOS CONVERTER
1
ICS508
REV H 051310
ICS508
PECL TO CMOS CONVERTER
PECL TO CMOS TRANSLATOR
Pin Assignment
VDDP
PECLIN
PECLIN
GND
1
2
3
4
8
7
6
5
VDDC
CLK
GND
OE
8 Pin (150 mil) SOIC
Pin Descriptions
Pin
Number
1
2
3
4
5
6
7
8
Pin
Name
VDDP
PECLIN
PECLIN
GND
OE
GND
CLK
VDDC
Pin
Type
Output
Input
Input
Power
Input
Power
Output
Power
Pin Description
Connect to 3.3V or 5V. Supplies PECL input buffer.
Complementary PECL clock input.
PECL clock input.
Connect to ground.
Output enable. Tri-states CLK output when low. Internal pull-up to
VDDC.
Connect to ground.
Clock output.
Connect to 2.5 V, or 3.3 V, or 5 V. Supplies output buffer and OE pin.
External Components
The ICS508 requires two 0.01µF decoupling capacitors to be connected between VDDP and GND and
between VDDC and GND. They must be connected close to the ICS508 to minimize lead inductance. A
33Ω series terminating resistor can be used next to the CLK pin.
IDT™ / ICS™
PECL TO CMOS CONVERTER
2
ICS508
REV H 051310
ICS508
PECL TO CMOS CONVERTER
PECL TO CMOS TRANSLATOR
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the ICS508. These ratings, which
are standard values for IDT 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, VDDP and VDDC
PECL Inputs
Clock Output and OE Pin
Ambient Operating Temperature, ICS508
Ambient Operating Temperature, ICS508MI
Storage Temperature
Soldering Temperature
7V
Rating
-0.5 V to VDDP+0.5 V
-0.5 V to VDDC+0.5 V
0 to +70° C
-40 to +85° C
-65 to +150° C
260° C
Recommended Operation Conditions
Parameter
Ambient Operating Temperature, ICS508M
Ambient Operating Temperature, ICS508MI
Power Supply Voltage (measured in respect to GND)
Reference crystal parameters
Min.
0
-40
+3.15
Typ.
Max.
+70
+85
+3.45
Units
°
C
°
C
V
Refer to page 3
DC Electrical Characteristics
VDDP = VDDC =3.3V ±5%
, Ambient temperature 0 to +70° C, unless stated otherwise
Parameter
Operating Voltage
Peak to Peak Input Voltage
Common Mode Range
Symbol
VDD
VDD
Conditions
VDDP
VDDC
PECLIN
PECLIN
VDDP = 5 V
PECLIN
VDDP = 3.3 V
Min.
3
2.375
0.3
VDDP - 3.7
VDDP - 2.0
2
Typ.
Max.
5.5
5.5
1
VDDP - 0.6
VDDP - 0.6
VDDC
0.8
Units
V
V
V
V
V
V
V
Input High Voltage
Input Low Voltage
V
IH
V
IL
OE only
OE only
IDT™ / ICS™
PECL TO CMOS CONVERTER
3
ICS508
REV H 051310
ICS508
PECL TO CMOS CONVERTER
PECL TO CMOS TRANSLATOR
Parameter
Output High Voltage
Symbol
V
OH
Conditions
VDDC = 5 V
IOH = -24 mA
VDDC = 3.3 V
IOH = -18 mA
VDDC = 2.5 V
IOH = -8 mA
Min.
VDDC - 0.4
VDDC - 0.4
VDDC - 0.4
Typ.
Max.
Units
V
V
V
Output Low Voltage
V
OL
VDDC = 5 V
IOL = 24 mA
VDDC = 3.3 V
IOL = 18 mA
VDDC = 2.5 V
IOL = 8 mA
0.4
0.4
0.4
250
1.5
8
V
V
V
kΩ
mA
mA
On Chip Pull-up Resistor
Operating Supply Current
R
PU
IDDP
IDDC
OE
100 MHz, no load
100 MHz, no load
Note 1: VDDP must always be greater than or equal to VDDC
AC Electrical Characteristics
VDDP = VDDC = 3.3V±5%
, Ambient Temperature 0 to +70° C, unless stated otherwise
Parameter
Input Frequency
Output Clock Rise Time
Symbol
f
IN
100 MHz
100 MHz
100 MHz
Conditions
0.8 V to 2.0 V, VDDP=VDDC = 5 V
0.8 V to 2.0 V, VDDP=VDDC=3.3 V
0.8 V to 2.0 V, VDDP=VDDC=2.5 V
2.0 V to 0.8 V, VDDP=VDDC = 5 V
2.0 V to 0.8 V, VDDP=VDDC=3.3 V
2.0 V to 0.8 V, VDDP=VDDC=2.5 V
OE high to output on 0 - 100 MHz
OE low to tri-state 0 - 100 MHz
VDDP = 5 V, VDDC = 5 V,
Min. Typ. Max. Units
0
0.4
0.6
1
0.4
0.6
1
7
7
4
4.5
5.5
4.5
5.5
45
20
20
6
7
9
7
9
55
250
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
%
Output Clock Fall Time
100 MHz
100 MHz
100 MHz
Output Enable Time
Output Disable Time
Propagation Delay
100 MHz
100 MHz
100 MHz VDDP = 5 V, VDDC = 3.3 V
100 MHz VDDP = 5 V, VDDC = 2.5 V
100 MHz VDDP = 3.3 V, VDDC = 3.3 V
VDDP = 3.3 V, VDDC = 2.5 V
Output Clock Duty
Cycle 0 - 100 MHz
Any VDD combination
IDT™ / ICS™
PECL TO CMOS CONVERTER
4
ICS508
REV H 051310
ICS508
PECL TO CMOS CONVERTER
PECL TO CMOS TRANSLATOR
Parameter
Output Clock Duty
Cycle
100 - 166 MHz
Symbol
Conditions
VDDP = 5 V, VDDC = 5 V
VDDP = 5 V, VDDC = 3.3 V
VDDP = 5 V, VDDC = 2.5 V
VDDP = 3.3 V, VDDC = 3.3 V
VDDP = 3.3 V, VDDC = 2.5 V
Min. Typ. Max. Units
45
45
40
40
45
40
40
35
35
40
55
55
60
60
55
60
60
65
65
60
%
%
%
%
%
%
%
%
%
%
Output Clock Duty
Cycle
166 - 250 MHz
VDDP = 5 V, VDDC = 5 V
VDDP = 5 V, VDDC = 3.3 V
VDDP = 5 V, VDDC = 2.5 V
VDDP = 3.3 V, VDDC = 3.3 V
VDDP = 3.3 V, VDDC = 2.5 V
Thermal Characteristics
Parameter
Thermal Resistance Junction to
Ambient
Symbol
θ
JA
θ
JA
θ
JA
θ
JC
Conditions
Still air
1 m/s air flow
3 m/s air flow
Min.
Typ.
150
140
120
40
Max. Units
°
C/W
°
C/W
°
C/W
°
C/W
Thermal Resistance Junction to Case
IDT™ / ICS™
PECL TO CMOS CONVERTER
5
ICS508
REV H 051310
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