Low Skew, 1-to-4 Multiplexed Differential/
LVCMOS-to-LVCMOS/LVTTL Fanout Buffer
ICS8305
DATA SHEET
General Description
Features
The ICS8305 is a low skew, 1-to-4, Differential/ LVCMOS-toLVCMOS/LVTTL Fanout Buffer. The ICS8305 has selectable clock
inputs that accept either differential or single ended input levels. The
clock enable is internally synchronized to eliminate runt pulses on
the outputs during asynchronous assertion/deassertion of the clock
enable pin. Outputs are forced LOW when the clock is disabled. A
separate output enable pin controls whether the outputs are in the
active or high impedance state.
•
•
•
Four LVCMOS / LVTTL outputs, 7 output impedance
•
LVCMOS_CLK supports the following input types: LVCMOS,
LVTTL
•
•
•
•
•
Maximum output frequency: 350MHz
•
•
0°C to 70°C ambient operating temperature
Guaranteed output and part-to-part skew characteristics make the
ICS8305 ideal for those applications demanding well defined
performance and repeatability.
Block Diagram
Selectable differential or LVCMOS / LVTTL clock inputs
CLK, nCLK pair can accept the following differential input levels:
LVPECL, LVDS, LVHSTL, HCSL, SSTL
Output skew: 35ps (maximum)
Part-to-part skew: 700ps (maximum)
Additive phase jitter, RMS: 0.04ps (typical)
Power supply modes:
Core/Output
3.3V/3.3V
3.3V/2.5V
3.3V/1.8V
3.3V/1.5V
Available in lead-free (RoHS 6) package
Pin Assignment
CLK_EN Pullup
GND
OE
VDD
CLK_EN
CLK
nCLK
CLK_SEL
LVCMOS_CLK
D
Q
LE
LVCMOS_CLK Pulldown
00
CLK Pulldown
nCLK Pullup/
11
Q0
Pulldown
CLK_SEL Pullup
Q1
Q2
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
Q0
VDDO
Q1
GND
Q2
VDDO
Q3
GND
ICS8305
16-Lead TSSOP
4.4mm x 3.0mm x 0.925mm package body
G Package
Q3
OE Pullup
Top View
ICS8305AG REVISION C MAY 30, 2014
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©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
Table 1. Pin Descriptions
Number
Name
1, 9, 13
GND
Power
Type
Description
2
OE
Input
3
VDD
Power
4
CLK_EN
Input
Pullup
5
CLK
Input
Pulldown
Non-inverting differential clock input.
6
nCLK
Input
Pullup/
Pulldown
Inverting differential clock input. VDD/2 default when left floating.
7
CLK_SEL
Input
Pullup
8
LVCMOS_CLK
Input
Pulldown
10, 12, 14, 16
Q3, Q2, Q1, Q0
Output
Single-ended clock outputs. 7 output impedance.
LVCMOS/LVTTL interface levels.
11, 15
VDDO
Power
Output supply pins.
Power supply ground
Pullup
Output enable. When LOW, outputs are in HIGH impedance state.
When HIGH, outputs are active. LVCMOS/LVTTL interface levels.
Power supply pin.
Synchronizing clock enable. When LOW, the output clocks are disabled.
When HIGH, output clocks are enabled. LVCMOS/LVTTL interface levels.
Clock select input. When HIGH, selects CLK, nCLK inputs. When LOW,
selects LVCMOS_CLK input. LVCMOS/LVTTL interface levels.
Single-ended clock input. LVCMOS/LVTTL interface levels.
NOTE: Pullup and Pulldown refer to internal input resistors. See Table 2, Pin Characteristics, for typical values.
Table 2. Pin Characteristics
Symbol
Parameter
CIN
Input Capacitance
4
pF
RPULLUP
Input Pullup Resistor
51
k
RPULLDOWN
Input Pulldown Resistor
51
k
CPD
Power Dissipation Capacitance
(per output)
11
pF
ROUT
Output Impedance
7
ICS8305AG REVISION C MAY 30, 2014
Test Conditions
2
Minimum
Typical
Maximum
Units
©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
Function Tables
Table 3. Control Input Function Table
Inputs
Outputs
OE
CLK_EN
CLK_SEL
Selected Source
Q0:Q3
1
0
0
LVCMOS_CLK
Disabled; Low
1
0
1
CLK/nCLK
Disabled; Low
1
1
0
LVCMOS_CLK
Enabled
1
1
1
CLK/nCLK
Enabled
0
X
X
Hi-Z
After CLK_EN switches, the clock outputs are disabled or enabled following a rising and falling input clock edge as shown in Figure 1.
Enabled
Disabled
nCLK
CLK,
LVCMOS_CLK
CLK_EN
Q0:Q3
Figure 1. CLK_EN Timing Diagram
ICS8305AG REVISION C MAY 30, 2014
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©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
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.
Item
Rating
Supply Voltage, VDD
4.6V
Inputs, VI
-0.5V to VDD + 0.5V
Outputs, VO
-0.5V to VDDO+ 0.5V
Package Thermal Impedance, JA
89C/W (0 lfpm)
Storage Temperature, TSTG
-65C to 150C
DC Electrical Characteristics
Table 4A. Power Supply DC Characteristics, VDD = 3.3V±5%, VDDO = 3.3V±5% or 2.5V±5% or 1.8V±0.5V or 1.5V±5%,
TA = 0°C to 70°C
Symbol
Parameter
VDD
Positive Supply Voltage
VDDO
Test Conditions
Minimum
Typical
Maximum
Units
3.135
3.3
3.465
V
3.135
3.3
3.465
V
2.375
2.5
2.625
V
1.65
1.8
1.95
V
1.425
1.5
1.575
V
Output Supply Voltage
IDD
Power Supply Current
21
mA
IDDO
Output Supply Current
5
mA
ICS8305AG REVISION C MAY 30, 2014
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©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
Table 4B. LVCMOS/LVTTL DC Characteristics, TA = 0°C to 70°C
Symbol
Parameter
VIH
Input High
Voltage
VIL
IIH
IIL
VOH
VOL
Input Low
Voltage
Input
High Current
Input
Low Current
Test Conditions
Minimum
Typical
Maximum
Units
CLK_EN,
CLK_SEL, OE
2
VDD + 0.3
V
LVCMOS_CLK
2
VDD + 0.3
V
CLK_EN,
CLK_SEL, OE
-0.3
0.8
V
LVCMOS_CLK
-0.3
1.3
V
CLK_EN,
CLK_SEL, OE
VDD = VIN = 3.465V
5
µA
LVCMOS_CLK
VDD = VIN = 3.465V
150
µA
CLK_EN,
CLK_SEL, OE
VDD = 3.465V, VIN = 0V
-150
µA
LVCMOS_CLK
VDD = 3.465V, VIN = 0V
-5
µA
VDDO = 3.3V ± 5%
2.6
V
VDDO = 2.5V ± 5%
1.8
V
VDDO = 1.8V ± 0.15V
1.5
V
VDDO = 1.5V ± 5%
VDDO - 0.3
V
Output High Voltage; NOTE 1
Output Low Voltage; NOTE 1
IOZL
Output Hi-Z Current Low
IOZH
Output Hi-Z Current High
VDDO = 3.3V ± 5%
0.5
V
VDDO = 2.5V ± 5%
0.5
V
VDDO = 1.8V ± 0.15V
0.4
V
VDDO = 1.5V ± 5%
0.35
V
-5
µA
5
µA
NOTE 1: Outputs terminated with 50 to VDDO/2. See Parameter Measurement Information, Output Load Test Circuit diagrams.
Table 4C. Differential DC Characteristics, TA = -40°C to 85°C
Symbol
Parameter
Test Conditions
Input High
Current
nCLK
IIH
IIL
Input Low
Current
VPP
Peak-to-Peak Voltage;
NOTE 1
VCMR
Common Mode Input Voltage;
NOTE 1, 2
Minimum
Typical
Maximum
Units
VDD = VIN = 3.465V
150
µA
CLK
VDD = VIN = 3.465V
150
µA
nCLK
VDD = 3.465V, VIN = 0V
-150
µA
CLK
VDD = 3.465V, VIN = 0V
-5
µA
0.15
1.3
V
GND + 0.5
VDD – 0.85
V
NOTE 1: VIL should not be less than -0.3V.
NOTE 2: Common mode input voltage is defined as VIH.
ICS8305AG REVISION C MAY 30, 2014
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©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
AC Electrical Characteristics
Table 5A. AC Characteristics, VDD = VDDO = 3.3V ± 5%, TA = 0°C to 70°C
Parameter
Symbol
Test Conditions
fMAX
Output Frequency
tpLH
Propagation
Delay,
Low to High
tsk(o)
Output Skew; NOTE 2, 6
tsk(pp)
Part-to-Part Skew; NOTE 3, 6
tjit
Buffer Additive Phase Jitter, RMS;
refer to Additive Phase Jitter
Section, NOTE 5
tR / tF
Output Rise/Fall Time;
NOTE 4
odc
Output Duty Cycle
tEN
Output Enable Time; NOTE 4
tDIS
Output Disable Time; NOTE 4
LVCMOS_CLK;
NOTE 1A
CLK/nCLK;
NOTE 1B
Minimum
Typical
1.75
Measured on the Rising Edge
Maximum
Units
350
MHz
2.75
ns
35
ps
700
ps
0.04
ps
20% to 80%
100
700
ps
Ref = CLK/nCLK
45
55
%
Ref = LVCMOS_CLK, ƒ 300MHz
45
55
%
5
ns
5
ns
NOTE: Electrical parameters are guaranteed over the specified ambient operating temperature range, which is established when the device is
mounted in a test socket with maintained transverse airflow greater than 500 lfpm. The device will meet specifications after thermal equilibrium
has been reached under these conditions.
All parameters measured at ƒ 350MHz unless noted otherwise.
NOTE 1A: Measured from the VDD/2 of the input to VDDO/2 of the output.
NOTE 1B: Measured from the differential input crossing point to VDDO/2 of the output.
NOTE 2: Defined as skew between outputs at the same supply voltage and with equal load conditions. Measured at VDDO/2.
NOTE 3: Defined as skew between outputs on different devices operating a the same supply voltages and with equal load conditions. Using
the same type of input on each device, the output is measured at VDDO/2.
NOTE 4: These parameters are guaranteed by characterization. Not tested in production.
NOTE 5: Driving only one input clock.
NOTE 6: This parameter is defined in accordance with JEDEC Standard 65.
Table 5B. AC Characteristics, VDD = 3.3V ± 5%, VDDO = 2.5V ± 5%, TA = 0°C to 70°C
Parameter
Symbol
fMAX
Output Frequency
Test Conditions
tpLH
Propagation
Delay,
Low to High
tsk(o)
Output Skew; NOTE 2, 6
tsk(pp)
Part-to-Part Skew; NOTE 3, 6
tjit
Buffer Additive Phase Jitter, RMS;
refer to Additive Phase Jitter
Section, NOTE 5
tR / tF
Output Rise/Fall Time; NOTE 4
odc
Output Duty Cycle
tEN
Output Enable Time; NOTE 4
tDIS
Output Disable Time; NOTE 4
LVCMOS_CLK;
NOTE 1A
CLK/nCLK;
NOTE 1B
Minimum
Typical
1.8
Measured on the Rising Edge
Maximum
Units
350
MHz
2.9
ns
35
ps
800
ps
0.04
ps
20% to 80%
100
700
ps
Ref = CLK/nCLK
44
56
%
Ref = LVCMOS_CLK, ƒ 300MHz
44
56
%
5
ns
5
ns
For NOTES, see Table 5A above.
ICS8305AG REVISION C MAY 30, 2014
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©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
Table 5C. AC Characteristics, VDD = 3.3V ± 5%, VDDO = 1.8V ± 0.15V, TA = 0°C to 70°C
Parameter
Symbol
fMAX
Output Frequency
Test Conditions
LVCMOS_CLK;
NOTE 1A
CLK/nCLK;
NOTE 1B
tpLH
Propagation
Delay,
Low to High
tsk(o)
Output Skew; NOTE 2, 6
tsk(pp)
Part-to-Part Skew; NOTE 3, 6
tjit
Buffer Additive Phase Jitter, RMS;
refer to Additive Phase Jitter
Section, NOTE 5
tR / tF
Output Rise/Fall Time; NOTE 4
odc
Output Duty Cycle
tEN
Output Enable Time; NOTE 4
tDIS
Output Disable Time; NOTE 4
Minimum
Typical
1.95
Measured on the Rising Edge
Maximum
Units
350
MHz
3.65
ns
35
ps
900
ps
0.04
ps
20% to 80%
100
700
ps
Ref = CLK/nCLK
44
56
%
Ref = LVCMOS_CLK, ƒ 300MHz
44
56
%
5
ns
5
ns
NOTE: Electrical parameters are guaranteed over the specified ambient operating temperature range, which is established when the device is
mounted in a test socket with maintained transverse airflow greater than 500 lfpm. The device will meet specifications after thermal equilibrium
has been reached under these conditions.
All parameters measured at ƒ 350MHz unless noted otherwise.
NOTE 1A: Measured from the VDD/2 of the input to VDDO/2 of the output.
NOTE 1B: Measured from the differential input crossing point to VDDO/2 of the output.
NOTE 2: Defined as skew between outputs at the same supply voltage and with equal load conditions. Measured at VDDO/2.
NOTE 3: Defined as skew between outputs on different devices operating a the same supply voltages and with equal load conditions. Using
the same type of input on each device, the output is measured at VDDO/2.
NOTE 4: These parameters are guaranteed by characterization. Not tested in production.
NOTE 5: Driving only one input clock.
NOTE 6: This parameter is defined in accordance with JEDEC Standard 65.
Table 5D. AC Characteristics, VDD = 3.3V ± 5%, VDDO = 1.5V ± 5%, TA = 0°C to 70°C
Parameter
Symbol
fMAX
Output Frequency
Test Conditions
LVCMOS_CLK;
NOTE 1A
CLK/nCLK;
NOTE 1B
tpLH
Propagation
Delay,
Low to High
tsk(o)
Output Skew; NOTE 2, 6
tsk(pp)
Part-to-Part Skew; NOTE 3, 6
tjit
Buffer Additive Phase Jitter, RMS;
refer to Additive Phase Jitter
Section, NOTE 5
tR / tF
Output Rise/Fall Time; NOTE 4
odc
Output Duty Cycle
tEN
Output Enable Time; NOTE 4
tDIS
Output Disable Time; NOTE 4
Minimum
Typical
2
Measured on the Rising Edge
Maximum
Units
350
MHz
4
ns
35
ps
1
ns
0.04
ps
20% to 80%
200
900
ps
ƒ 166MHz
45
55
%
ƒ > 166MHz
42
58
%
5
ns
5
ns
For NOTES, see Table 5C above.
ICS8305AG REVISION C MAY 30, 2014
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©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
Additive Phase Jitter
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.
0
-10
Additive Phase Jitter at 155.52MHz
= 0.04ps (typical)
-20
-30
-40
-50
-60
SSB Phase Noise dBc/Hz
-70
-80
-90
-100
-110
-120
-130
-140
-150
-160
-170
-180
-190
100
1k
10k
100k
1M
10M
100M
Offset Frequency (Hz)
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
ICS8305AG REVISION C MAY 30, 2014
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.
8
©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
Parameter Measurement Information
1.65V±5%
2.05V±5%
1.25V±5%
SCOPE
VDD,
VDDO
SCOPE
VDD
VDDO
Qx
LVCMOS
Qx
GND
CL ≤ 25pF*
*For tR/tF measurement only
-1.65V±5%
-1.25V±5%
3.3V Core/2.5V LVCMOS Output Load AC Test Circuit
3.3V Core/3.3V LVCMOS Output Load AC Test Circuit
2.55V±5%
2.4V±0.09V
0.75V±5%
0.9V±0.075V
SCOPE
VDD
VDDO
SCOPE
VDD
VDDO
Qx
GND
Qx
GND
-0.9V±0.075V
-0.9V±0.75V
3.3V Core/1.5V LVCMOS Output Load AC Test Circuit
3.3V Core/1.8V LVCMOS Output Load AC Test Circuit
VDD
VCCO
2
Qx
nCLK
V
PP
Cross Points
V
VCCO
2
CMR
CLK
Qy
tsk(b)
GND
Output Skew
Differential Input Level
ICS8305AG REVISION C MAY 30, 2014
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©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
Parameter Measurement Information, continued
V
Part 1
DDO
DDO
Qx
2
Q0:Q3
V
t PW
2
t
PERIOD
Part 2
V
DDO
Qy
2
tsk(pp)
odc =
t PW
x 100%
t PERIOD
Part-to-Part Skew
Output Duty Cycle/Pulse Width/Period
LVCMOS_CLK
80%
VDDO
2
nCLK
80%
CLK
Clock
Outputs
20%
20%
tR
tF
VDDO
2
Q0:Q3
➤
Output Rise/Fall Time
ICS8305AG REVISION C MAY 30, 2014
tPD
➤
Propagation Delay
10
©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
Application Information
Recommendations for Unused Input and Output Pins
Inputs:
Outputs:
LVCMOS_CLK Input
LVCMOS Outputs
For applications not requiring the use of a clock input, it can be left
floating. Though not required, but for additional protection, a 1k
resistor can be tied from the LVCMOS_CLK input to ground.
All unused LVCMOS outputs can be left floating. There should be no
trace attached.
CLK/nCLK Inputs
For applications not requiring the use of the differential input, both
CLK and nCLK can be left floating. Though not required, but for
additional protection, a 1k resistor can be tied from CLK to ground.
LVCMOS Control Pins
All control pins have internal pull-ups or pull-downs; additional
resistance is not required but can be added for additional protection.
A 1k resistor can be used.
Wiring the Differential Input to Accept Single Ended Levels
Figure 2 shows how a differential input can be wired to accept single
ended levels. The reference voltage V1= VDD/2 is generated by the
bias resistors R1 and R2. The bypass capacitor (C1) is used to help
filter noise on the DC bias. This bias circuit should be located as close
to the input pin as possible. The ratio of R1 and R2 might need to be
adjusted to position the V1in the center of the input voltage swing. For
example, if the input clock swing is 2.5V and VDD = 3.3V, R1 and R2
value should be adjusted to set V1 at 1.25V. The values below are for
when both the single ended swing and VDD are at the same voltage.
This configuration requires that the sum of the output impedance of
the driver (Ro) and the series resistance (Rs) equals the transmission
line impedance. In addition, matched termination at the input will
attenuate the signal in half. This can be done in one of two ways.
First, R3 and R4 in parallel should equal the transmission line
impedance. For most 50 applications, R3 and R4 can be 100. The
values of the resistors can be increased to reduce the loading for
slower and weaker LVCMOS driver. When using single-ended
signaling, the noise rejection benefits of differential signaling are
reduced. Even though the differential input can handle full rail
LVCMOS signaling, it is recommended that the amplitude be
reduced. The datasheet specifies a lower differential amplitude,
however this only applies to differential signals. For single-ended
applications, the swing can be larger, however VIL cannot be less
than -0.3V and VIH cannot be more than VDD + 0.3V. Though some
of the recommended components might not be used, the pads
should be placed in the layout. They can be utilized for debugging
purposes. The datasheet specifications are characterized and
guaranteed by using a differential signal.
Figure 2. Recommended Schematic for Wiring a Differential Input to Accept Single-ended Levels
ICS8305AG REVISION C MAY 30, 2014
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©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
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 3A to 3F show interface examples for the
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 3A, the input termination
applies for IDT open emitter LVHSTL drivers. If you are using an
LVHSTL driver from another vendor, use their termination
recommendation.
3.3V
1.8V
Zo = 50Ω
CLK
Zo = 50Ω
nCLK
Differential
Input
LVHSTL
IDT
LVHSTL Driver
R1
50Ω
R2
50Ω
Figure 3A. CLK/nCLK Input
Driven by an IDT Open Emitter LVHSTL Driver
Figure 3B. CLK/nCLK Input
Driven by a 3.3V LVPECL Driver
Figure 3C. CLK/nCLK Input
Driven by a 3.3V LVPECL Driver
Figure 3D. CLK/nCLK Input
Driven by a 3.3V LVDS Driver
3.3V
2.5V
3.3V
3.3V
2.5V
R3
120Ω
*R3
R4
120Ω
Zo = 60Ω
CLK
CLK
Zo = 60Ω
nCLK
nCLK
HCSL
*R4
Differential
Input
SSTL
R1
120Ω
Figure 3E. CLK/nCLK Input
Driven by a 3.3V HCSL Driver
ICS8305AG REVISION C MAY 30, 2014
R2
120Ω
Differential
Input
Figure 3F. CLK/nCLK Input
Driven by a 2.5V SSTL Driver
12
©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
Schematic Example
This application note provides general design guide using ICS8305
LVCMOS buffer. Figure 4 shows a schematic example of the
ICS8305 LVCMOS clock buffer. In this example, the input is driven by
an LVCMOS driver. CLK_EN is set at logic low to select
LVCMOS_CLK input.
VDD
Zo = 50
VDD
R1
43
R4
1K
R5
1K
U1
1
2
3
4
5
6
7
8
VDD
Zo = 50
Ro ~ 7 Ohm
R3
GND
OE
VDD
CLK_EN
CLK
nCLK
CLK_SEL
LVCMOS_CLK
Q0
VDDO
Q1
GND
Q2
VDDO
Q3
GND
16
15
14
13
12
11
10
9
LVCMOS Receiv er
Zo = 50
R2
43
43
3,.3V LVCMOS
R6
1K
ICS8305
(U1,3)
(U1,11)
(U1,15)
C1
C2
C3
0.1u
0.1u
0.1u
VDD
VDD=3.3V
LVCMOS Receiv er
Figure 4. ICS8305 LVCMOS Clock Output Buffer Schematic Example
ICS8305AG REVISION C MAY 30, 2014
13
©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
Reliability Information
Table 6. JA vs. Air Flow Table for a 16 Lead TSSOP
JA vs. Air Flow
Linear Feet per Minute
0
200
500
Single-Layer PCB, JEDEC Standard Test Boards
137.1°C/W
118.2°C/W
106.8°C/W
Multi-Layer PCB, JEDEC Standard Test Boards
89.0°C/W
81.8°C/W
78.1°C/W
NOTE: Most modern PCB design use multi-layered boards. The data in the second row pertains to most designs.
Transistor Count
The transistor count for ICS8305: 459
Package Outline and Package Dimensions
Package Outline - G Suffix for 16 Lead TSSOP
Table 7. Package Dimensions for 16 Lead TSSOP
Symbol
N
A
A1
A2
b
c
D
E
E1
e
L
aaa
All Dimensions in Millimeters
Minimum
Maximum
16
1.20
0.5
0.15
0.80
1.05
0.19
0.30
0.09
0.20
4.90
5.10
6.40 Basic
4.30
4.50
0.65 Basic
0.45
0.75
0°
8°
0.10
Reference Document: JEDEC Publication 95, MO-153
ICS8305AG REVISION C MAY 30, 2014
14
©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
Ordering Information
Table 8. Ordering Information
Part/Order Number
8305AGLF
8305AGLFT
Marking
8305AGLF
8305AGLF
ICS8305AG REVISION C MAY 30, 2014
Package
“Lead-Free” 16 Lead TSSOP
“Lead-Free” 16 Lead TSSOP
15
Shipping Packaging
Tube
Tape & Reel
Temperature
0C to 70C
0C to 70C
©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
Revision History Sheet
Rev
A
B
B
C
C
C
Table
Page
T8
14
T5A - T5C
5&6
7
T1
T4A
T4B
T5D
C
1/20/04
Added Additive Phase Jitter to AC Characteristics Tables.
Added Additive Phase Jitter Section.
2/26/04
2
Pin Description Table - corrected CLK_EN description.
12/6/04
1
Features Section - added 1.5V output to Supply Mode bullet and
added Lead-Free bullet.
Power Supply DC Characteristics Table - added VDDO 1.5V.
LVCMOS DC Characteristics Table - added VOH/VOL 1.5V.
Added 3.3V/1.5V AC Characteristics Table.
Added 3.3V/1.5V Output Load AC Test Circuit Drawing.
Added Recommendations for Unused Input and Output Pins.
Added Lead-Free part number.
11/17/05
Ordering Information Table - added lead-free marking.
Corrected non-lead free marking from ICS8305AG to 8305AG.
2/22/08
Updated to current datasheet format
Deleted HiPerClockS references.
Added Note: Electrical parameters are guaranteed ... to Notes
Updated the ‘Wiring the Differential Input to Accept Single Ended Levels’ section
Deleted: ICS from part numbers; quantity from shipping; LF Note; disclaimer.
9/17/12
Features Section - removed leaded part reference
Ordering Information - removed leaded parts. PDN# CQ-13-02
Updated Technical Support contact email address
5/30/14
T8
T8
15
8
T8
Date
Ordering Information table - corrected Part/Order Number typo from
ICS88305AGT to ICS8305AGT.
4
4
7
10
11
16
T5A-T5D
Description of Change
1, 12
6, 7
11
15
1
15
17
ICS8305AG REVISION C MAY 30, 2014
16
©2014 Integrated Device Technology, Inc.
ICS8305 Data Sheet
LOW SKEW, 1-TO-4 MULTIPLEXED DIFFERENTIAL/LVCMOS-TO-LVCMOS/LVTTL FANOUT BUFFER
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