Document
LOW SKEW 1 TO 4 CLOCK BUFFER
DATASHEET
ICS651
Description
The ICS651 is a low skew, single input to four output, clock buffer. Part of IDT’s ClockBlocksTM family, this is a low skew, small clock buffer.
IDT makes many non-PLL and PLL based low skew output devices as well as Zero Delay Buffers to synchronize clocks. Contact us for all of your clocking needs.
Features
• Low skew outputs (250 ps) • Packaged in 8-pin SOIC • RoHS 6 compliant package • Low power CMOS technology • Operating Voltages of 1.5 V to 2.5 V • Output Enable pin tri-states outputs • 3.3 V tolerant input clock • Industrial or commercial temperature ranges
Block Diagram
ICLK
Q0 Q1 Q2 Q3
Output Enable
IDT® LOW SKEW 1 TO 4 CLOCK BUFFER
1
ICS651
REV H 101111
ICS651 LOW SKEW 1 TO 4 CLOCK BUFFER
Pin Assignment
ICLK
Q1 Q2 Q3
1 2 3 4
8 OE 7 VDD 6 GND 5 Q4
FAN OUT BUFFER
Pin Descriptions
Pin Number
1 2 3 4 5 6 7 8
Pin Name
ICLK Q1 Q2 Q3 Q4 GND VDD OE
Pin Type
Input Output Output Output Output Power Power Input
Pin Description
Clock Input. 3.3 V tolerant input. Clock Output 1. Clock Output 2. Clock Output 3. Clock Output 4. Connect to ground. Connect to +1.5 V or +2.5 V. Output Enable. Tri-states outputs when low. Connect to VDD for normal operation.
External Components
A minimum number of external components are required for proper operation. A decoupling capacitor of 0.01 μF should be connected between VDD on pin 7 and GND on pin 6, as close to the device as possible. A 33 Ω series terminating resistor may be used on each clock output if the trace is longer than 1 inch.
To achieve the low output skew that the ICS651 is capable of, careful attention must be paid to board layout. Essentially, all four outputs must have identical terminations, identical loads and identical trace geometries. If they do not, the output skew will be degraded. For example, using a 30Ω series termination on one output (with 33Ω on the others) will cause at least 15 ps of skew.
IDT® LOW SKEW 1 TO 4 CLOCK BUFFER
2
ICS651
REV H 101111
ICS651 LOW SKEW 1 TO 4 CLOCK BUFFER
FAN OUT BUFFER
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the ICS651. 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, VDD Output Enable and All Outputs ICLK Ambient Operating Temperature (industrial) Ambient Operating Temperature (commercial) Storage Temperature Junction Temperature Soldering Temperature
Rating
7V -0.5 V to VDD+0.5 V -0.5 V to 3.6 V (VDD > 0V) -40 to +85 ° C 0 to +70 ° C -65 to +150° C 125° C 260° C
Recommended Operation Conditions
Parameter
Ambient Operating Temperature (industrial) Ambient Operating Temperature (commercial) Power Supply Voltage (measured in respect to GND)
Min.
-40 0 +1.425
Typ.
Max.
+85 +70 +2.625
Units
°C °C V
IDT® LOW SKEW 1 TO 4 CLOCK BUFFER
3
ICS651
REV H 101111
ICS651 LOW SKEW 1 TO 4 CLOCK BUFFER
FAN OUT BUFFER
DC Electrical Characteristics
VDD=1.5 V ±5%, Ambient temperature -40 to +85° C or 0 to +70° C, unless stated otherwise
Parameter
Symbol Conditions
Min. Typ. Max.
Operating Voltage
VDD
1.425
1.575
Input High Voltage Input Low Voltage Output High Voltage Output Low Voltage Operating Supply Current
VIH Note 1, ICLK, OE 1.17
3.6
VIL Note 1, ICLK, OE
0.63
VOH IOH = -6 mA
1.35
VOL IOL = 6 mA
0.45
IDD No load, 133 MHz
25
Nominal Output Impedance
ZO
Input Capacitance
CIN ICLK, OE pin
Short Circuit Current
IOS
Notes: 1. Nominal switching threshold is VDD/2
20 5 ±28
Units
V V V V V mA Ω pF mA
VDD=1.8 V ±5%, Ambient temperature -40 to +85° C or 0 to +70° C, unless stated otherwise
Parameter
Symbol Conditions
Min. Typ. Max.
Operating Voltage
VDD
1.71 1.8 1.89
Input High Voltage, ICLK Input Low Voltage, ICLK Output High Voltage Output Low Voltage Operating Supply Current
VIH Note 1, ICLK, OE 1.17
3.6
VIL Note 1, ICLK, OE
0.63
VOH IOH = -8 mA
1.35
VOL IOL = 8mA
0.45
IDD No load, 133 MHz
30
Nominal Output Impedance
ZO
Input Capacitance
CIN ICLK, OE pin
Short Circuit Current
IOS
Notes: 1. Nominal switching threshold is VDD/2
20 5 ±32
Units
V V V V V mA Ω pF mA
VDD=2.5 V ±5%, Ambient temperature -40 to +85° C or 0 to +70° C, unless stated otherwise
Parameter
Symbol Conditions
Min. Typ. Max.
Operating Voltage
VDD
2.375
2.625
Input High Voltage, ICLK Input Low Voltage, ICLK Output High Voltage Output Low Voltage Operating Supply Current
VIH Note 1, ICLK, OE
1.7
3.6
VIL Note 1, ICLK, OE
0.7
VOH IOH = -8 mA
2
VOL IOL = 8mA
0.4
IDD No load, 133 MHz
50
Nominal.