IDT2305B
3.3V ZERO DELAY CLOCK BUFFER
COMMERCIAL AND INDUSTRIAL TEMPERATURE RANGES
3.3V ZERO DELAY
CLOCK BUFFER
FEATURES:
•
•
•
•
•
•
•
•
•
•
•
•
Phase-Lock Loop Clock Distribution
10MHz to 133MHz operating frequency
Distributes one clock input to one bank of five outputs
Zero Input-Output Delay
Output Skew < 250ps
Low jitter <200 ps cycle-to-cycle
IDT2305B-1 for Standard Drive
IDT2305B-1H for High Drive
No external RC network required
Operates at 3.3V V
DD
Power down mode
Available in SOIC package
IDT2305B
ADVANCE
INFORMATION
DESCRIPTION:
The IDT2305B is a high-speed phase-lock loop (PLL) clock buffer,
designed to address high-speed clock distribution applications. The zero
delay is achieved by aligning the phase between the incoming clock and
the output clock, operable within the range of 10 to 133MHz.
The IDT2305B is an 8-pin version of the IDT2309B. IDT2305B accepts
one reference input, and drives out five low skew clocks. The -1H version
of this device operates, up to 133MHz frequency and has a higher drive
than the -1 device. All parts have on-chip PLLs which lock to an input clock
on the REF pin. The PLL feedback is on-chip and is obtained from the
CLKOUT pad. In the absence of an input clock, the IDT2305B enters power
down. In this mode, the device will draw less than 25
µA,
the outputs are
tri-stated, and the PLL is not running, resulting in a significant reduction of
power.
The IDT2305B is characterized for both Industrial and Commercial
operation.
NOTE:
For new designs, refer to AN-233.
FUNCTIONAL BLOCK DIAGRAM
8
CLKOUT
REF
1
PLL
Control
Logic
3
CLK1
2
CLK2
5
7
CLK3
CLK4
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
COMMERCIAL AND INDUSTRIAL TEMPERATURE RANGES
1
c
2005
Integrated Device Technology, Inc.
OCTOBER 2005
DSC 6994/-
IDT2305B
3.3V ZERO DELAY CLOCK BUFFER
COMMERCIAL AND INDUSTRIAL TEMPERATURE RANGES
PIN CONFIGURATION
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
V
DD
Rating
Supply Voltage Range
Input Voltage Range (REF)
Input Voltage Range
(except REF)
I
IK
(V
I
< 0)
I
O
(V
O
= 0 to V
DD
)
V
DD
or GND
T
A
= 55°C
(in still air)
(3)
T
STG
Storage Temperature Range
Commercial Temperature
Range
Industrial Temperature
Range
-40 to +85
°C
–65 to +150
0 to +70
°C
°C
Input Clamp Current
Continuous Output Current
Continuous Current
Maximum Power Dissipation
Max.
–0.5 to +4.6
–0.5 to +5.5
–0.5 to
V
DD
+0.5
–50
±50
±100
0.7
mA
mA
mA
W
Unit
V
V
V
V
I (2)
V
I
REF
CLK2
CLK1
GND
1
2
3
4
8
7
6
5
CLKOUT
CLK4
V
DD
CLK3
SOIC
TOP VIEW
Operating
Temperature
Operating
Temperature
NOTES:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause
permanent damage to the device. This is a stress rating only and functional operation
of the device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect reliability.
2. The input and output negative-voltage ratings may be exceeded if the input and output
clamp-current ratings are observed.
3. The maximum package power dissipation is calculated using a junction temperature
of 150°C and a board trace length of 750 mils.
APPLICATIONS:
•
•
•
•
•
SDRAM
Telecom
Datacom
PC Motherboards/Workstations
Critical Path Delay Designs
PIN DESCRIPTION
Pin Name
REF
(1)
CLK2
(2)
CLK1
GND
CLK3
(2)
V
DD
CLK4
(2)
CLKOUT
(2)
NOTES:
1. Weak pull down.
2. Weak pull down on all outputs.
(2)
Pin Number
1
2
3
4
5
6
7
8
Type
IN
Out
Out
Ground
Out
PWR
Out
Out
Output clock
Output clock
Ground
Output clock
3.3V Supply
Output clock
Functional Description
Input reference clock, 5 Volt tolerant input
Output clock, internal feedback on this pin
2
IDT2305B
3.3V ZERO DELAY CLOCK BUFFER
COMMERCIAL AND INDUSTRIAL TEMPERATURE RANGES
OPERATING CONDITIONS - COMMERCIAL
Symbol
V
DD
T
A
C
L
C
IN
Supply Voltage
Operating Temperature (Ambient Temperature)
Load Capacitance < 100MHz
Load Capacitance 100MHz - 133MHz
Input Capacitance
Parameter
Min.
3
0
—
—
—
Max.
3.6
70
30
10
7
pF
Unit
V
°
C
pF
DC ELECTRICAL CHARACTERISTICS - COMMERCIAL
Symbol
V
IL
V
IH
I
IL
I
IH
V
OL
V
OH
I
DD_PD
I
DD
Parameter
Input LOW Voltage Level
Input HIGH Voltage Level
Input LOW Current
Input HIGH Current
Output LOW Voltage
Output HIGH Voltage
Power Down Current
Supply Current
V
IN
= 0V
V
IN
= V
DD
Standard Drive
High Drive
Standard Drive
High Drive
REF = 0MHz
Unloaded Outputs at 66.66MHz
I
OL
= 8mA
I
OL
= 12mA (-1H)
I
OH
= -8mA
I
OH
= -12mA (-1H)
—
—
12
32
µA
mA
2.4
—
V
Conditions
Min.
—
2
—
—
—
Max.
0.8
—
50
100
0.4
Unit
V
V
µA
µA
V
SWITCHING CHARACTERISTICS (2305B-1) - COMMERCIAL
Symbol
t
1
Parameter
Output Frequency
Duty Cycle = t
2
÷
t
1
t
3
t
4
t
5
t
6
t
7
t
J
t
LOCK
Rise Time
Fall Time
Output to Output Skew
Delay, REF Rising Edge to CLKOUT Rising Edge
Device-to-Device Skew
Cycle-to-Cycle Jitter, pk - pk
PLL Lock Time
10pF Load
30pF Load
Measured at 1.4V, F
OUT
= 66.66MHz
Measured between 0.8V and 2V
Measured between 0.8V and 2V
All outputs equally loaded
Measured at V
DD
/2
Measured at V
DD
/2 on the CLKOUT pins of devices
Measured at 66.66MHz, loaded outputs
Stable power supply, valid clock presented on REF pin
Conditions
(1,2)
Min.
10
10
40
—
—
—
—
—
—
—
Typ.
—
—
50
—
—
—
0
0
—
—
Max.
133
100
60
2.5
2.5
250
±350
700
200
1
Unit
MHz
%
ns
ns
ps
ps
ps
ps
ms
NOTES:
1. REF Input has a threshold voltage of V
DD
/2.
2. All parameters specified with loaded outputs.
3
IDT2305B
3.3V ZERO DELAY CLOCK BUFFER
COMMERCIAL AND INDUSTRIAL TEMPERATURE RANGES
(1,2)
SWITCHING CHARACTERISTICS (2305B-1H) - COMMERCIAL
Symbol
t
1
Parameter
Output Frequency
Duty Cycle = t
2
÷
t
1
Duty Cycle = t
2
÷
t
1
t
3
t
4
t
5
t
6
t
7
t
8
t
J
t
LOCK
Rise Time
Fall Time
Output to Output Skew
Delay, REF Rising Edge to CLKOUT Rising Edge
Device-to-Device Skew
Output Slew Rate
Cycle-to-Cycle Jitter, pk - pk
PLL Lock Time
10pF Load
30pF Load
Measured at 1.4V, F
OUT
= 66.66MHz
Measured at 1.4V, F
OUT
<50MHz
Measured between 0.8V and 2V
Measured between 0.8V and 2V
All outputs equally loaded
Measured at V
DD
/2
Measured at V
DD
/2 on the CLKOUT pins of devices
Measured between 0.8V and 2V using Test Circuit #2
Measured at 66.66MHz, loaded outputs
Stable power supply, valid clock presented on REF pin
Conditions
Min.
10
10
40
45
—
—
—
—
—
1
—
—
Typ.
—
—
50
50
—
—
—
0
0
—
—
—
Max.
133
100
60
55
1.5
1.5
250
±350
700
—
200
1
Unit
MHz
%
%
ns
ns
ps
ps
ps
V/ns
ps
ms
NOTES:
1. REF Input has a threshold voltage of V
DD
/2.
2. All parameters specified with loaded outputs.
OPERATING CONDITIONS - INDUSTRIAL
Symbol
V
DD
T
A
C
L
C
IN
Supply Voltage
Operating Temperature (Ambient Temperature)
Load Capacitance < 100MHz
Load Capacitance 100MHz - 133MHz
Input Capacitance
Parameter
Min.
3
-40
—
—
—
Max.
3.6
+85
30
10
7
pF
Unit
V
°
C
pF
DC ELECTRICAL CHARACTERISTICS - INDUSTRIAL
Symbol
V
IL
V
IH
I
IL
I
IH
V
OL
V
OH
I
DD_PD
I
DD
Parameter
Input LOW Voltage Level
Input HIGH Voltage Level
Input LOW Current
Input HIGH Current
Output LOW Voltage
Output HIGH Voltage
Power Down Current
Supply Current
V
IN
= 0V
V
IN
= V
DD
Standard Drive
High Drive
Standard Drive
High Drive
REF = 0MHz
Unloaded Outputs at 66.66MHz
I
OL
= 8mA
I
OL
= 12mA (-1H)
I
OH
= -8mA
I
OH
= -12mA (-1H)
—
—
25
35
µA
mA
2.4
—
V
Conditions
Min.
—
2
—
—
—
Max.
0.8
—
50
100
0.4
Unit
V
V
µA
µA
V
4
IDT2305B
3.3V ZERO DELAY CLOCK BUFFER
COMMERCIAL AND INDUSTRIAL TEMPERATURE RANGES
(1,2)
SWITCHING CHARACTERISTICS (2305B-1) - INDUSTRIAL
Symbol
t
1
Parameter
Output Frequency
Duty Cycle = t
2
÷
t
1
t
3
t
4
t
5
t
6
t
7
t
J
t
LOCK
Rise Time
Fall Time
Output to Output Skew
Delay, REF Rising Edge to CLKOUT Rising Edge
Device-to-Device Skew
Cycle-to-Cycle Jitter, pk - pk
PLL Lock Time
10pF Load
30pF Load
Measured at 1.4V, F
OUT
= 66.66MHz
Measured between 0.8V and 2V
Measured between 0.8V and 2V
All outputs equally loaded
Measured at V
DD
/2
Measured at V
DD
/2 on the CLKOUT pins of devices
Measured at 66.66MHz, loaded outputs
Conditions
Min.
10
10
40
—
—
—
—
—
—
—
Typ.
—
—
50
—
—
—
0
0
—
—
Max.
133
100
60
2.5
2.5
250
±350
700
200
1
Unit
MHz
%
ns
ns
ps
ps
ps
ps
ms
Stable power supply, valid clock presented on REF pin
NOTES:
1. REF Input has a threshold voltage of V
DD
/2.
2. All parameters specified with loaded outputs.
SWITCHING CHARACTERISTICS (2305B-1H) - INDUSTRIAL
Symbol
t
1
Parameter
Output Frequency
Duty Cycle = t
2
÷
t
1
Duty Cycle = t
2
÷
t
1
t
3
t
4
t
5
t
6
t
7
t
8
t
J
t
LOCK
Rise Time
Fall Time
Output to Output Skew
Delay, REF Rising Edge to CLKOUT Rising Edge
Device-to-Device Skew
Output Slew Rate
Cycle-to-Cycle Jitter, pk - pk
PLL Lock Time
10pF Load
30pF Load
Measured at 1.4V, F
OUT
= 66.66MHz
Measured at 1.4V, F
OUT
<50MHz
Measured between 0.8V and 2V
Measured between 0.8V and 2V
All outputs equally loaded
Measured at V
DD
/2
Measured at V
DD
/2 on the CLKOUT pins of devices
Measured between 0.8V and 2V using Test Circuit #2
Measured at 66.66MHz, loaded outputs
Stable power supply, valid clock presented on REF pin
Conditions
(1,2)
Min.
10
10
40
45
—
—
—
—
—
1
—
—
Typ.
—
—
50
50
—
—
—
0
0
—
—
—
Max.
133
100
60
55
1.5
1.5
250
±350
700
—
200
1
Unit
MHz
%
%
ns
ns
ps
ps
ps
V/ns
ps
ms
NOTES:
1. REF Input has a threshold voltage of V
DD
/2.
2. All parameters specified with loaded outputs.
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