LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECL
FANOUT BUFFER
ICS85311
IDT™ / ICS™
LVPECL/ECL FANOUT BUFFER 1
ICS85311AM REV. D OCTOBER 22, 2008
General Description
The ICS85311 is a low skew, high perfor- mance
1-to-2 Differential-to-2.5V/3.3V ECL/LVPECL
Fanout Buffer and a member of the HiPerClockS™
family of High Performance Clock Solutions from
IDT. The CLK, nCLK pair can accept most standard
differential input levels.The ICS85311 is characterized to operate
from either a 2.5V or a 3.3V power supply. Guaranteed output and
part-to-part skew characteristics make the ICS85311 ideal for
those clock distribution applications demanding well defined
performance and repeatability.
Features
•Two differential 2.5V/3.3V LVPECL / ECL outputs
•One CLK, nCLK input pair
•CLK, nCLK pair can accept the following differential input levels:
LVDS, LVPECL, LVHSTL, SSTL, HCSL
•Maximum output frequency: 1GHz
•Translates any single ended input signal to 3.3V LVPECL levels
with resistor bias on nCLK input
•Output skew: 15ps (maximum)
•Part-to-part skew: 100ps (maximum)
•Propagation delay: 1.4ns (maximum)
•Additive phase jitter, RMS: 0.14ps (typical), 3.3V
•LVPECL mode operating voltage supply range:
VCC = 2.375V to 3.465V, VEE = 0V
•ECL mode operating voltage supply range:
VCC = 0V, VEE = -2.375V to -3.465V
•0°C to 70°C ambient operating temperature
•Available in both standard (RoHS 5) and lead-free (RoHS 6)
packages
HiPerClockS™
ICS
Q0
nQ0
Q1
nQ1
CLK
nCLK Pullup
Pulldown
1
2
3
4
8
7
6
5
VCC
CLK
nCLK
VEE
Q0
Q1
nQ1
nQ0
ICS85311
8-Lead SOIC
3.90mm x 4.903mm x 1.37mm package body
M Package
Top View
Pin Assignment
Block Diagram
ICS85311
LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECLFANOUT BUFFER
IDT™ / ICS™
LVPECL/ECL FANOUT BUFFER 2
ICS85311AM REV. D OCTOBER 22, 2008
Table 1. Pin Descriptions
NOTE: Pullup and Pulldown refer to internal input resistors. See Table 2, Pin Characteristics, for typical values.
Table 2. Pin Characteristics
Number Name Type Description
1, 2 Q0, nQ0 Output Differential output pair. LVPECL interface levels.
3, 4 Q1, nQ1 Output Differential output pair. LVPECL interface levels.
5V
EE Power Negative supply pin.
6 nCLK Input Pullup Inverting differential clock input.
7 CLK Input Pulldown Non-inverting differential clock input.
8V
CC Power Positive supply pin.
Symbol Parameter Test Conditions Minimum Typical Maximum Units
CIN Input Capacitance 4 pF
RPULLUP Input Pullup Resistor 51 kΩ
RPULLDOWN Input Pulldown Resistor 51 kΩ
ICS85311
LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECLFANOUT BUFFER
IDT™ / ICS™
LVPECL/ECL FANOUT BUFFER 3
ICS85311AM REV. D OCTOBER 22, 2008
Absolute Maximum Ratings
NOTE: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device.
These ratings are stress specifications only. Functional operation of product at these conditions or any conditions beyond
those listed in the DC Characteristics or AC Characteristics is not implied. Exposure to absolute maximum rating conditions for
extended periods may affect product reliability.
DC Electrical Characteristics
Table 3A. Power Supply DC Characteristics, VCC = 3.3V±5% or 2.5V±5%, VEE = 0V, TA = 0°C to 70°C
Table 3B. Differential DC Characteristics, VCC = 3.3V±5% or 2.5V±5%, VEE = 0V, TA = 0°C to 70°C
NOTE 1: VIL should not be less than -0.3V.
NOTE 2: Common mode voltage is defined as VIH.
Item Rating
Supply Voltage, VCC 4.6V
Inputs, VI-0.5V to VCC + 0.5V
Outputs, IO
Continuos Current
Surge Current
50mA
100mA
Storage Temperature, TSTG -65°C to 150°C
Package Thermal Impedance, θJA 112°C/W (0 lfpm)
Symbol Parameter Test Conditions Minimum Typical Maximum Units
VCC Positive Supply Voltage 3.135 3.3 3.465 V
2.375 2.5 2.625 V
IEE Power Supply Current 25 mA
Symbol Parameter Test Conditions Minimum Typical Maximum Units
IIH Input High Current nCLK VCC = VIN = 3.465V or 2.625V 5 µA
CLK VCC = VIN = 3.465V or 2.625V 150 µA
IIL Input Low Cureent nCLK VCC = 3.465V or 2.625V, VIN = 0V -150 µA
CLK VCC = 3.465V or 2.625V, VIN = 0V -5 µA
VPP
Peak-to-Peak Input Voltage;
NOTE 1 0.15 1.3 V
VCMR
Common Mode Input Voltage;
NOTE 1, 2 VEE + 0.5 VCC – 0.85 V
ICS85311
LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECLFANOUT BUFFER
IDT™ / ICS™
LVPECL/ECL FANOUT BUFFER 4
ICS85311AM REV. D OCTOBER 22, 2008
Table 3C. LVPECL DC Characteristics, VCC = 3.3V±5% or 2.5V±5%, VEE = 0V, TA = 0°C to 70°C
NOTE1: Outputs terminated with 50Ω to VCC – 2V.
AC Electrical Characteristics
Table 4A. AC Characteristics, VCC = 3.3V±5%, VEE = 0V, TA = 0°C to 70°C
NOTE: Electrical parameters are guaranteed over the specified ambient operating temperature range, which is established when device
is mounted in a test socket with maintained transverse airflow greater than 500 lfpm. Device will meet specifications after thermal
equilibrium has been reached under these conditions.
All parameters are measured 500MHz unless otherwise noted.
NOTE 1: Measured from the differential input crossing point to the differential output crossing point.
NOTE 2: Defined as skew between outputs at the same supply voltage and with equal load conditions. Measured at the differential cross
points.
NOTE 3: Defined as skew between outputs on different devices operating at the same supply voltages and with equal load conditions.
Using the same type of inputs on each device, the outputs are measured at the differential cross points.
NOTE 4: This parameter is defined in accordance with JEDEC Standard 65.
Table 4B. AC Characteristics, VCC = 2.5V±5%, VEE = 0V, TA = 0°C to 70°C
See Table 5A for NOTES.
Symbol Parameter Test Conditions Minimum Typical Maximum Units
VOH Output High Current; NOTE 1 VCC – 1.4 VCC – 0.9 V
VOL Output Low Current; NOTE 1 VCC – 2.0 VCC – 1.7 V
VSWING Peak-to-Peak Output Voltage Swing 0.65 1.0 V
Symbol Parameter Test Conditions Minimum Typical Maximum Units
fMAX Maximum Output Frequency 1GHz
tPD Propagation Delay; NOTE 1 ƒ ≤ 1GHz 0.9 1.4 ns
tjit
Buffer Additive Phase Jitter,
RMS; refer to Additive Phase
Jitter Section
156.25MHz, Integration Range
(12kHz – 20MHz) 0.14 ps
tsk(o) Output Skew; NOTE 2, 4 15 ps
tsk(pp) Part-to-Part Skew; NOTE 3, 4 100 ps
tR / tFOutput Rise/Fall Time 20% to 80% @ 50MHz 300 700 ps
odc Output Duty Cycle 48 52 %
Symbol Parameter Test Conditions Minimum Typical Maximum Units
fMAX Maximum Output Frequency 1GHz
tPD Propagation Delay; NOTE 1 ƒ ≤ 1GHz 0.9 1.4 ns
tjit
Buffer Additive Phase Jitter,
RMS; refer to Additive Phase
Jitter Section
156.25MHz, Integration Range
(12kHz – 20MHz) 0.135 ps
tsk(o) Output Skew; NOTE 2, 4 15 ps
tsk(pp) Part-to-Part Skew; NOTE 3, 4 100 ps
tR / tFOutput Rise/Fall Time 20% to 80% @ 50MHz 300 700 ps
odc Output Duty Cycle 48 52 %
ICS85311
LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECLFANOUT BUFFER
IDT™ / ICS™
LVPECL/ECL FANOUT BUFFER 5
ICS85311AM REV. D OCTOBER 22, 2008
Additive Phase Jitter (3.3V)
The spectral purity in a band at a specific offset from the
fundamental compared to the power of the fundamental is called
the dBc Phase Noise. This value is normally expressed using a
Phase noise plot and is most often the specified plot in many
applications. Phase noise is defined as the ratio of the noise power
present in a 1Hz band at a specified offset from the fundamental
frequency to the power value of the fundamental. This ratio is
expressed in decibels (dBm) or a ratio of the power in the 1Hz band
to the power in the fundamental. When the required offset is
specified, the phase noise is called a dBc value, which simply
means dBm at a specified offset from the fundamental. By
investigating jitter in the frequency domain, we get a better
understanding of its effects on the desired application over the
entire time record of the signal. It is mathematically possible to
calculate an expected bit error rate given a phase noise plot.
As with most timing specifications, phase noise measurements
has issues relating to the limitations of the equipment. Often the
noise floor of the equipment is higher than the noise floor of the
device. This is illustrated above. The device meets the noise floor
of what is shown, but can actually be lower. The phase noise is
dependent on the input source and measurement equipment.
Offset Frequency (Hz)
SSB Phase Noise dBc/Hz
Additive Phase Jitter @ 156.25MHz
12kHz to 20MHz = 0.14ps (typical)
ICS85311
LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECLFANOUT BUFFER
IDT™ / ICS™
LVPECL/ECL FANOUT BUFFER 6
ICS85311AM REV. D OCTOBER 22, 2008
Parameter Measurement Information
3.3V Core/ 3.3V LVPECL Output Load AC Test Circuit
Differential Input Level
Part-to-Part Skew
2.5V Core/ 2.5V LVPECL Output Load AC Test Circuit
Output Skew
Propagation Delay
SCOPE
Qx
nQx
LVPECL
VEE
VCC
2V
-1.3V ± 0.165V
VCMR
Cross Points
VPP
VCC
VEE
nCLK
CLK
tsk(pp)
Part 1
Part 2
nQx
Qx
nQy
Qy
SCOPE
Qx
nQx
LVPECL
VEE
VCC
2V
-0.5V ± 0.125V
tsk(o)
nQx
Qx
nQy
Qy
tPD
nCLK
CLK
nQ[0:1]
Q[0:1]
ICS85311
LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECLFANOUT BUFFER
IDT™ / ICS™
LVPECL/ECL FANOUT BUFFER 7
ICS85311AM REV. D OCTOBER 22, 2008
Parameter Measurement Information, continued
Output Duty Cycle/Pulse Width/Period Output Rise/Fall Time
Application Information
Wiring the Differential Input to Accept Single Ended Levels
Figure 1 shows how the differential input can be wired to accept
single ended levels. The reference voltage V_REF = VCC/2 is
generated by the bias resistors R1, R2 and C1. This bias circuit
should be located as close as possible to the input pin. The ratio of
R1 and R2 might need to be adjusted to position the V_REF in the
center of the input voltage swing. For example, if the input clock
swing is only 2.5V and VCC = 3.3V, V_REF should be 1.25V and
R2/R1 = 0.609.
Figure 1. Single-Ended Signal Driving Differential Input
nQ[0:1]
Q[0:1]
tPW
tPERIOD
tPW
tPERIOD
odc = x 100%
20%
80% 80%
20%
tRtF
VSWING
nQ[0:1]
Q[0:1]
V_REF
Single Ended Clock Input
VCC
CLK
nCLK
R1
1K
C1
0.1u R2
1K
ICS85311
LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECLFANOUT BUFFER
IDT™ / ICS™
LVPECL/ECL FANOUT BUFFER 8
ICS85311AM REV. D OCTOBER 22, 2008
Differential Clock Input Interface
The CLK /nCLK accepts LVDS, LVPECL, LVHSTL, SSTL, HCSL
and other differential signals. Both signals must meet the VPP and
VCMR input requirements. Figures 2A to 2F show interface
examples for the HiPerClockS CLK/nCLK input driven by the most
common driver types. The input interfaces suggested here are
examples only. Please consult with the vendor of the driver
component to confirm the driver termination requirements. For
example, in Figure 2A, the input termination applies for IDT
HiPerClockS open emitter LVHSTL drivers. If you are using an
LVHSTL driver from another vendor, use their termination
recommendation.
Figure 2A. HiPerClockS CLK/nCLK Input
Driven by an IDT Open Emitter
HiPerClockS LVHSTL Driver
Figure 2C. HiPerClockS CLK/nCLK Input
Driven by a 3.3V LVPECL Driver
Figure 2E. HiPerClockS CLK/nCLK Input
Driven by a 3.3V HCSL Driver
Figure 2B. HiPerClockS CLK/nCLK Input
Driven by a 3.3V LVPECL Driver
Figure 2D. HiPerClockS CLK/nCLK Input
Driven by a 3.3V LVDS Driver
Figure 2F. HiPerClockS CLK/nCLK Input
Driven by a 2.5V SSTL Driver
R1
50
R2
50
1.8V
Zo = 50Ω
Zo = 50Ω
CLK
nCLK
3.3V
LVHSTL
IDT
HiPerClockS
LVHSTL Driver
HiPerClockS
Input
R3
125
R4
125
R1
84
R2
84
3.3V
Zo = 50Ω
Zo = 50Ω
CLK
nCLK
3.3V
3.3V
LVPECL HiPerClockS
Input
HCSL
*R3 33
*R4 33
CLK
nCLK
2.5V 3.3V
Zo = 50Ω
Zo = 50Ω
HiPerClockS
Input
R1
50
R2
50
*Optional – R3 and R4 can be 0Ω
CLK
nCLK
HiPerClockS
Input
LVPECL
3.3V
Zo = 50Ω
Zo = 50Ω
3.3V
R1
50
R2
50
R2
50
3.3V
R1
100
LVDS
CLK
nCLK
3.3V
Receiver
Zo = 50Ω
Zo = 50Ω
CLK
nCLK
HiPerClockS
SSTL
2.5V
Zo = 60Ω
Zo = 60Ω
2.5V
3.3V
R1
120
R2
120
R3
120
R4
120
ICS85311
LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECLFANOUT BUFFER
IDT™ / ICS™
LVPECL/ECL FANOUT BUFFER 9
ICS85311AM REV. D OCTOBER 22, 2008
Recommendations for Unused Output Pins
Outputs:
LVPECL Outputs
All unused LVPECL outputs can be left floating. We recommend
that there is no trace attached. Both sides of the differential output
pair should either be left floating or terminated.
Termination for 3.3V LVPECL Outputs
The clock layout topology shown below is a typical termination for
LVPECL outputs. The two different layouts mentioned are
recommended only as guidelines.
FOUT and nFOUT are low impedance follower outputs that
generate ECL/LVPECL compatible outputs. Therefore, terminating
resistors (DC current path to ground) or current sources must be
used for functionality. These outputs are designed to drive 50Ω
transmission lines. Matched impedance techniques should be
used to maximize operating frequency and minimize signal
distortion. Figures 3A and 3B show two different layouts which are
recommended only as guidelines. Other suitable clock layouts may
exist and it would be recommended that the board designers
simulate to guarantee compatibility across all printed circuit and
clock component process variations.
Figure 3A. 3.3V LVPECL Output Termination Figure 3B. 3.3V LVPECL Output Termination
VCC - 2V
50Ω50Ω
RTT
Zo = 50Ω
Zo = 50Ω
FOUT FIN
RTT = Zo
1
((VOH + VOL) / (VCC – 2)) – 2
3.3V
125Ω125Ω
84Ω84Ω
Zo = 50Ω
Zo = 50Ω
FOUT FIN
ICS85311
LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECLFANOUT BUFFER
IDT™ / ICS™
LVPECL/ECL FANOUT BUFFER 10
ICS85311AM REV. D OCTOBER 22, 2008
Termination for 2.5V LVPECL Outputs
Figure 4A and Figure 4B show examples of termination for 2.5V
LVPECL driver. These terminations are equivalent to terminating
50Ω to VCC – 2V. For VCC = 2.5V, the VCC – 2V is very close to
ground level. The R3 in Figure 4B can be eliminated and the
termination is shown in Figure 4C.
Figure 4A. 2.5V LVPECL Driver Termination Example
Figure 4C. 2.5V LVPECL Driver Termination Example
Figure 4B. 2.5V LVPECL Driver Termination Example
2.5V LVPECL Driver
VCC = 2.5V
2.5V
2.5V
50Ω
50Ω
R1
250
R3
250
R2
62.5
R4
62.5
+
–
2.5V LVPECL Driver
VCC = 2.5V
2.5V
50Ω
50Ω
R1
50
R2
50
+
–
2.5V LVPECL Driver
VCC = 2.5V
2.5V
50Ω
50Ω
R1
50
R2
50
R3
18
+
–
ICS85311
LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECLFANOUT BUFFER
IDT™ / ICS™
LVPECL/ECL FANOUT BUFFER 11
ICS85311AM REV. D OCTOBER 22, 2008
Power Considerations
This section provides information on power dissipation and junction temperature for the ICS85311.
Equations and example calculations are also provided.
1. Power Dissipation.
The total power dissipation for the ICS85311 is the sum of the core power plus the power dissipated in the load(s).
The following is the power dissipation for VCC = 3.3V + 5% = 3.465V, which gives worst case results.
NOTE: Please refer to Section 3 for details on calculating power dissipated in the load.
• Power (core)MAX = VCC_MAX * IEE_MAX = 3.465V * 25mA = 86.6mW
• Power (outputs)MAX = 30mW/Loaded Output pair
If all outputs are loaded, the total power is 2 * 30mW = 60mW
Total Power_MAX (3.3V, with all outputs switching) = 86.6mW + 60mW = 146.6mW
2. Junction Temperature.
Junction temperature, Tj, is the temperature at the junction of the bond wire and bond pad and directly affects the reliability of the device.
The maximum recommended junction temperature for HiPerClockS devices is 125°C.
The equation for Tj is as follows: Tj = θJA * Pd_total + TA
Tj = Junction Temperature
θJA = Junction-to-Ambient Thermal Resistance
Pd_total = Total Device Power Dissipation (example calculation is in section 1 above)
TA = Ambient Temperature
In order to calculate junction temperature, the appropriate junction-to-ambient thermal resistance θJA must be used. Assuming a moderate
air flow of 200 linear feet per minute and a multi-layer board, the appropriate value is 103.3°C/W per Table 5 below.
Therefore, Tj for an ambient temperature of 70°C with all outputs switching is:
70°C + 0.147W * 103.3°C/W = 85.2°C. This is well below the limit of 125°C.
This calculation is only an example. Tj will obviously vary depending on the number of loaded outputs, supply voltage, air flow and the type
of board (single layer or multi-layer).
Table 5. Thermal Resistance θJA for 24 Lead TSSOP, Forced Convection
NOTE: Most modern PCB designs use multi-layered boards. The data in the second row pertains to most designs.
θJA vs. Air Flow
Linear Feet per Minute 0200500
Single-Layer PCB, JEDEC Standard Test Boards 153.3°C/W 128.5°C/W 115.5°C/W
Multi-Layer PCB, JEDEC Standard Test Boards 112.7°C/W 103.3°C/W 97.1°C/W
ICS85311
LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECLFANOUT BUFFER
IDT™ / ICS™
LVPECL/ECL FANOUT BUFFER 12
ICS85311AM REV. D OCTOBER 22, 2008
3. Calculations and Equations.
The purpose of this section is to derive the power dissipated into the load.
LVPECL output driver circuit and termination are shown in Figure 5.
Figure 5. LVPECL Driver Circuit and Termination
To calculate worst case power dissipation into the load, use the following equations which assume a 50Ω load, and a termination voltage
of VCC – 2V.
• For logic high, VOUT = VOH_MAX = VCC_MAX – 0.9V
(VCC_MAX – VOH_MAX) = 0.9V
• For logic low, VOUT = VOL_MAX = VCC_MAX – 1.7V
(VCC_MAX – VOL_MAX) = 1.7V
Pd_H is power dissipation when the output drives high.
Pd_L is the power dissipation when the output drives low.
Pd_H = [(VOH_MAX – (VCC_MAX – 2V))/RL] * (VCC_MAX – VOH_MAX) = [(2V – (VCC_MAX – VOH_MAX))/RL] * (VCC_MAX – VOH_MAX) =
[(2V – 0.9V)/50Ω] * 0.9V = 19.8mW
Pd_L = [(VOL_MAX – (VCC_MAX – 2V))/RL] * (VCC_MAX – VOL_MAX) = [(2V – (VCC_MAX – VOL_MAX))/RL] * (VCC_MAX – VOL_MAX) =
[(2V – 1.7V)/50Ω] * 1.7V = 10.2mW
Total Power Dissipation per output pair = Pd_H + Pd_L = 30mW
VOUT
VCC
VCC
- 2V
Q1
RL
50Ω
ICS85311
LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECLFANOUT BUFFER
IDT™ / ICS™
LVPECL/ECL FANOUT BUFFER 13
ICS85311AM REV. D OCTOBER 22, 2008
Reliability Information
Table 6. θJA vs. Air Flow Table for a 8 Lead SOIC
NOTE: Most modern PCB designs use multi-layered boards. The data in the second row pertains to most designs.
Transistor Count
The transistor count for ICS85311 is: 225
Package Outline and Package Dimensions
Package Outline - M Suffix for 8 Lead SOIC Table 7. Package Dimensions
Reference Document: JEDEC Publication 95, MS-012
θJA by Velocity
Linear Feet per Minute 0200500
Single-Layer PCB, JEDEC Standard Test Boards 153.3°C/W 128.5°C/W 115.5°C/W
Multi-Layer PCB, JEDEC Standard Test Boards 112.7°C/W 103.3°C/W 97.1°C/W
150 il (N B d ) SOIC
All Dimensions in Millimeters
Symbol Minimum Maximum
N8
A1.35 1.75
A1 0.10 0.25
B0.33 0.51
C0.19 0.25
D4.80 5.00
E3.80 4.00
e1.27 Basic
H5.80 6.20
h0.25 0.50
L0.40 1.27
α0° 8°
ICS85311
LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECLFANOUT BUFFER
IDT™ / ICS™
LVPECL/ECL FANOUT BUFFER 14
ICS85311AM REV. D OCTOBER 22, 2008
Ordering Information
Table 8. Ordering Information
NOTE: Parts that are ordered with an "LF" suffix to the part number are the Pb-Free configuration and are RoHS compliant.
Part/Order Number Marking Package Shipping Packaging Temperature
85311AM 85311AM 8 Lead SOIC Tube 0°C to 70°C
85311AMT 85311AM 8 Lead SOIC 2500 Tape & Reel 0°C to 70°C
85311AMLF 85311ALF “Lead-Free” 8 Lead SOIC Tube 0°C to 70°C
85311AMLFT 85311ALF “Lead-Free” 8 Lead SOIC 2500 Tape & Reel 0°C to 70°C
While the information presented herein has been checked for both accuracy and reliability, Integrated Device Technology (IDT) assumes no responsibility for either its use or for
the infringement of any patents or other rights of third parties, which would result from its use. No other circuits, patents, or licenses are implied. This product is intended for use
in normal commercial applications. Any other applications, such as those requiring extended temperature ragnes, high reliability or other extraordinary environmental requirements
are not recommended without additional processing by IDT. IDT reserves the right to change any circuitry or specifications without notice. IDT does not authorize or warrant any
IDT product for use in life support devices or critical medical instruments.
ICS85311
LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECLFANOUT BUFFER
IDT™ / ICS™
LVPECL/ECL FANOUT BUFFER 15
ICS85311AM REV. D OCTOBER 22, 2008
Revision History Sheet
Rev Table Page Description of Change Date
A 8 Added Termination for LVPECL Outputs section. 5/30/02
A
5
7
3.3V Output Load Test Circuit Diagram - corrected VEE equation to read
-1.3V ± 0.165V from ± 0.135V.
Updated Output Rise/Fall Time Diagram.
9/23/02
B
T2
T8
1
2
3
3
5
6
7
8
13
Add Lead-Free bullet in Features section.
Pin Characteristics table - changed CIN 4pF max. to 4pF typical.
Absolute Maximum Ratings, updated Outputs rating.
Combined 3.3V & 2.5V Power tables and Differential DC Characteristics tables.
Updated Parameter Measurement Information.
Updated Single Ended Signal Driving Differential Input diagram.
Added Termination for 2.5V LVPECL Output section.
Added Differential Clock Input Interface section.
Ordering Information table - added Lead Free part number.
6/17/04
BT8
7
13
Added Recommendations for Unused Input and Output Pins.
Ordering Information Table - corrected Lead-Free marking and added
Lead-Free Note.
7/28/05
C
T3 3
9 - 10
LVPECL DC Characteristics Table -corrected VOH max. from VCC - 1.0V to VCCO -
0.9V; and VSWING max. from 0.9V to 1.0V.
Power Considerations - corrected power dissipation to reflect VOH max in Table 3C.
4/11/07
D
T4A - T4B 4
5
8
Added 2.5V AC Characteristics Table. Added Additive Phase Jitter spec to both AC
Tables.
Added Additive Phase Jitter plot.
Updated Differential Input Clock Interface section.
10/22/08
ICS85311
LOW SKEW, 1-TO-2, DIFFERENTIAL-TO-LVPECL/ECLFANOUT BUFFER
www.IDT.com
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+408-284-8200 (outside USA)
Contact Information:
www.IDT.com
