ICS87931BYILFT [IDT]
PLL Based Clock Driver, 6 True Output(s), 0 Inverted Output(s), PQFP32, 7 X 7 MM, 1.40 MM HEIGHT, MS-026, LQFP-32;![ICS87931BYILFT](http://pdffile.icpdf.com/pdf2/p00307/img/icpdf/ICS87931BYIL_1850059_icpdf.jpg)
型号: | ICS87931BYILFT |
厂家: | ![]() |
描述: | PLL Based Clock Driver, 6 True Output(s), 0 Inverted Output(s), PQFP32, 7 X 7 MM, 1.40 MM HEIGHT, MS-026, LQFP-32 驱动 逻辑集成电路 |
文件: | 总16页 (文件大小:165K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
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Low Skew, 1-to-6, LVCMOS/LVTTL Clock
Multiplier/Zero Delay Buffer
ICS87931I
GENERAL DESCRIPTION
FEATURES
• Fully integrated PLL
The ICS87931I is a low voltage, low skew LVCMOS/LVTTL Clock
Multiplier/Zero Delay Buffer.With output frequencies up to 150MHz,
the ICS87931I is targeted for high performance clock applica-
tions. Along with a fully integrated PLL, the ICS87931I contains
frequency configurable outputs and an external feedback input
for regenerating clocks with “zero delay”.
• Six LVCMOS/LVTTL outputs, 7Ω typical output impedance
• Selectable differential CLK0, nCLK0 or LVCMOS/LVTTL
clock for redundant clock applications
• Maximum output frequency: 150MHz
• VCO range: 220MHz to 480MHz
Selectable clock inputs, CLK1 and differential CLK0, nCLK0 sup-
port redundant clock applications.The CLK_SEL input determines
which reference clock is used. The output divider values of Bank
A, B and C are controlled by the DIV_SELA, DIV_SELB and
DIV_SELC, respectively.
• External feedback for “zero delay” clock regeneration
• Output skew, Same Frequency: 300ps (maximum)
• Output skew, Different Frequency: 400ps (maximum)
• Cycle-to-cycle jitter: 100ps (maximum)
For test and system debug purposes, the PLL_SEL input allows
the PLL to be bypassed. When LOW, the nMR input resets the • 3.3V supply voltage
internal dividers and forces the outputs to the high impedance
state.
• -40°C to 85°C ambient operating temperature
The effective fanout of the ICS87931I can be increased to 12 by
utilizing the ability of each output to drive two series terminated
transmission lines.
PIN ASSIGNMENT
32 31 30 29 28 27 26 25
1
2
3
4
5
6
7
8
24
23
22
21
20
19
18
17
nc
VDDA
GND
QB0
ICS87931I
POWER_DN
CLK1
QB1
32-Lead LQFP
VDDO
7mm x 7mm x 1.4mm
package body
nMR
EXTFB_SEL
CLK_SEL
PLL_SEL
nc
CLK0
Y package
TopView
nCLK0
GND
BLOCK DIAGRAM
9
10 11 12 13 14 15 16
Pullup
POWER_DN
Pullup
PLL_SEL
Pulldown
Pullup
CLK1
CLK_SEL
0
Pullup
None
1
0
CLK0
0
1
QA0
QA1
÷2/÷4
÷2/÷4
PHASE
DETECTOR
1
VCO
÷2
nCLK0
Pulldown
Pullup
LPF
EXTFB_SEL
EXT_FB
1
0
QB0
QB1
÷8
Pulldown
Pulldown
DIV_SELA
DIV_SELB
Pullup
÷4/÷6
QC0
QC1
CLK_EN0
CLK_EN1
DIV_SELC
DISABLE
LOGIC
Pullup
Pulldown
POWER-ON RESET
Pullup
nMR
ICS87931BYI REVISION A AUGUST 25, 2010
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©2010 Integrated Device Technology, Inc.
ICS87931I
LOW SKEW, 1-TO-6, LVCMOS/LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER
TABLE 1. PIN DESCRIPTIONS
Number
1, 9, 17, 32
2
Name
nc
Type
Unused
Description
No connect.
VDDA
Power
Input
Input
Analog supply pin.
Controls the frequency being fed to the output dividers.
LVCMOS / LVTTL interface levels.
3
4
POWER_DN
CLK1
Pullup
Pullup
Clock input. LVCMOS / LVTTL interface levels.
Active LOW Master reset. When logic LOW, the internal dividers are
reset causing the outputs to go low. When logic HIGH, the internal
dividers and the outputs are enabled. LVCMOS / LVTTL interface levels.
5
nMR
Input
Pullup
Pullup
6
7
CLK0
nCLK0
GND
Input
Input
Power
Input
Non-inverting differential clock input.
Pullup/
Pulldown
Inverting differential clock input. VCC/2 default when left floating.
8, 16, 24,25
10, 11
Power supply ground.
CLK_EN0,
CLK_EN1
Controls the enabling and disabling of the clock outputs. See Table 3B.
LVCMOS / LVTTL interface levels.
External feedback. When LOW, selects internal feedback.
When HIGH, selects EXT_FB. LVCMOS / LVTTL interface levels.
Pullup
Pullup
12
EXT_FB
VDDO
Input
Power
Output
13, 21, 28
14, 15
Output supply pins.
Bank C clock outputs.7Ω typical output impedance.
LVCMOS / LVTTL interface levels.
QC0, QC1
Selects between the PLL and reference clocks as the input to the
output dividers. When HIGH, selects PLL. When LOW, bypasses
the PLL. LVCMOS / LVTTL interface levels.
18
19
PLL_SEL
CLK_SEL
Input
Input
Pullup
Clock select input. Selects the Phase Detector Reference.
Pulldown When LOW, selects CLK0, nCLK0. When HIGH, selects CLK1.
LVCMOS / LVTTL interface levels.
20
EXTFB_SEL
QB1, QB0
Input
Pulldown External feedback select. LVCMOS / LVTTL interface levels.
Bank B clock outputs.7Ω typical output impedance.
LVCMOS / LVTTL interface levels.
22, 23
Output
Bank A clock outputs.7Ω typical output impedance.
LVCMOS / LVTTL interface levels.
Determines output divider values for Bank A as described in Table 4A.
LVCMOS / LVTTL interface levels.
Determines output divider values for Bank B as described in Table 4A.
LVCMOS / LVTTL interface levels.
Determines output divider values for Bank C as described in Table 4A.
LVCMOS / LVTTL interface levels.
26, 27
29
QA1, QA0
DIV_SELA
DIV_SELB
DIV_SELC
Output
Input
Input
Input
Pulldown
30
Pulldown
31
Pulldown
NOTE: Pullup and Pulldown refer to internal input resistors. See table 2, Pin Characteristics, for typical values.
TABLE 2. PIN CHARACTERISTICS
Symbol
CIN
Parameter
Test Conditions
Minimum Typical Maximum Units
Input Capacitance
Input Pullup Resistor
Input Pulldown Resistor
4
pF
KΩ
KΩ
RPULLUP
RPULLDOWN
51
51
Power Dissipation Capacitance
(per output)
Output Impedance
CPD
VDDA, VDDO = 3.465V
12
7
pF
ROUT
Ω
ICS87931BYI REVISION A AUGUST 25, 2010
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©2010 Integrated Device Technology, Inc.
ICS87931I
LOW SKEW, 1-TO-6, LVCMOS/LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER
TABLE 3A. CONTROL INPUT FUNCTIONT ABLE
Inputs
Function
Control Pin
CLK_SEL
Logic 0
Logic 1
CLK1
CLK0, nCLK0
Bypass PLL
Internal Feedback
VCO/1
PLL_SEL
PLL Enabled
EXT_FB
EXTFB_SEL
POWER_DN
nMR
VCO/2
Master Reset/Output Hi Z
QA(÷2); QB(÷2); QC(÷4)
Enable Outputs
QA(÷4); QB(÷4); QC(÷6)
DIV_SELA:DIV_SELC
TABLE 3B. CLK_ENX FUNCTION TABLE
Inputs
DIV_SELA:DIVSELC
CLK_EN1
CLK_EN0
QAx
Toggle
LOW
QBx
LOW
LOW
LOW
Toggle
QCx
LOW
0
0
1
1
0
1
0
1
Toggle
Toggle
Toggle
Toggle
Toggle
TABLE 4A.VCO FREQUENCY FUNCTIONT ABLE
Inputs
Outputs
QBx
QAx
QCx
DIV_
DIV_
DIV_
SELA SELB SELC
POWER_DN = 0 POWER_DN = 1 POWER_DN = 0 POWER_DN = 1 POWER_DN = 0 POWER_DN = 1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
VCO/2
VCO/2
VCO/2
VCO/2
VCO/4
VCO/4
VCO/4
VCO/4
VCO/4
VCO/4
VCO/4
VCO/4
VCO/8
VCO/8
VCO/8
VCO/8
VCO/2
VCO/2
VCO/4
VCO/4
VCO/2
VCO/2
VCO/4
VCO/4
VCO/4
VCO/4
VCO/8
VCO/8
VCO/4
VCO/4
VCO/8
VCO/8
VCO/4
VCO/6
VCO/4
VCO/6
VCO/4
VCO/6
VCO/4
VCO/6
VCO/8
VCO/12
VCO/8
VCO/12
VCO/8
VCO/12
VCO/8
VCO/12
TABLE 4B. INPUT REFERENCE FREQUENCY TO OUTPUT FREQUENCY FUNCTIONTABLE (INTERNAL FEEDBACK ONLY, EXTFB_SEL = 0)
Inputs
Outputs
QBx
QAx
QCx
DIV_
DIV_
DIV_
SELA SELB SELC
POWER_DN = 0 POWER_DN = 1 POWER_DN = 0 POWER_DN = 1 POWER_DN = 0 POWER_DN = 1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
4x
4x
4x
4x
2x
2x
2x
2x
2x
2x
2x
2x
x
4x
4x
2x
2x
4x
4x
2x
2x
2x
2x
x
2x
4/3x
2x
x
2/3x
x
x
4/3x
2x
2/3x
x
2x
2x
x
x
4/3x
2x
2/3x
x
x
x
x
4/3x
2/3x
ICS87931BYI REVISION A AUGUST 25, 2010
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ICS87931I
LOW SKEW, 1-TO-6, LVCMOS/LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER
VCO
VCO/2
POWER_DN
QA(÷2)
QB(÷4)
QC(÷6)
FIGURE 1A. POWER_DN TIMING DIAGRAM
QA
QB
QC
CLK_EN0
CLK_EN1
QA(÷2)
QB(÷4)
QC(÷6)
CLK_EN0
CLK_EN1
FIGURE 1B. CLK_ENX TIMING DIAGRAMS
ICS87931BYI REVISION A AUGUST 25, 2010
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ICS87931I
LOW SKEW, 1-TO-6, LVCMOS/LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V
4.6V
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 be-
yond 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.
DD
Inputs, V
-0.5V to VDDA + 0.5 V
-0.5V to VDDO + 0.5V
I
Outputs, VO
Package Thermal Impedance, θ 47.9°C/W (0 lfpm)
JA
Storage Temperature, T
-65°C to 150°C
STG
TABLE 5A. POWER SUPPLY DC CHARACTERISTICS, VDDA = VDDO = 3.3V 5ꢀ, TA = -40°C TO 85°C
Symbol Parameter Test Conditions Minimum Typical Maximum Units
VDDA
VDDO
IDDA
Analog Supply Voltage
3.135
3.135
3.3
3.3
20
3.465
3.465
V
Output Supply Voltage
Analog Supply Current
Output Supply Current
V
mA
mA
IDDO
100
TABLE 5B. LVCMOS/LVTTL DC CHARACTERISTICS, VDDA = VDDO = 3.3V 5ꢀ, TA = -40°C TO 85°C
Symbol Parameter
Test Conditions
Minimum Typical Maximum Units
DIV_SELA:DIV_SELC,
CLK_EN0, CLK_EN1,
POWER_DN, nMR, CLK_SEL,
PLL_SEL, EXTFB_SEL
CLK1, EXT_FB
DIV_SELA:DIV_SELC,
CLK_EN0, CLK_EN1,
POWER_DN, nMR, CLK_SEL,
PLL_SEL, EXTFB_SEL
CLK1, EXT_FB
2
VDD + 0.3
V
V
V
Input
VIH
High Voltage
2
VDD + 0.3
-0.3
-0.3
2.4
0.8
Input
VIL
Low Voltage
1.3
V
µA
V
IIN
Input Current
120
VOH
VOL
Output High Voltage; NOTE 1
Output Low Voltage; NOTE 1
IOH = -20mA
IOL = 20mA
0.5
V
NOTE 1: Outputs terminated with 50Ω to VDDO/2. See Parameter Measurement section, 3.3V Output Load Test Circuit.
TABLE 5C. DIFFERENTIAL DC CHARACTERISTICS, VDDA = VDDO = 3.3V 5ꢀ, TA = -40°C TO 85°C
Symbol Parameter
Test Conditions
Minimum Typical Maximum Units
IIN
Input Current
120
1.3
µA
V
VPP
Peak-to-Peak Input Voltage
0.15
Common Mode Input Voltage;
NOTE 1
VCMR
GND + 0.5
VDD - 0.85
V
NOTE 1: Common mode voltage is defined as VIH.
ICS87931BYI REVISION A AUGUST 25, 2010
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©2010 Integrated DeviceTechnology, Inc.
ICS87931I
LOW SKEW, 1-TO-6, LVCMOS/LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER
TABLE 6. PLL INPUT REFERENCE CHARACTERISTICS, VDDA = VDDO = 3.3V 5ꢀ, TA = -40°C TO 85°C
Symbol Parameter Test Conditions Minimum Typical Maximum Units
Input Reference Frequency
fREF
NOTE: Input reference frequency is limited by
the divider selection and the VCO lock range.
150
MHz
TABLE 7. AC CHARACTERISTICS, VDDA = VDDO = 3.3V 5ꢀ, TA = -40°C TO 85°C
Symbol Parameter Test Conditions
Minimum Typical Maximum Units
QAx, QBx
÷2
÷4
÷6
150
120
80
MHz
MHz
MHz
ps
fMAX
Output Frequency QAx, QBx, QCx
QCx
CLK1 to EXT_FB
-375
-100
-200
50
-50
200
300
400
100
480
1
Propagation Delay;
NOTE 1
fref = 50MHz,
FB = ÷ 8
tPD
CLK0, nCLK0 to EXT_FB
ps
Same Frequency
ps
tsk(o)
Output Skew; NOTE 2, 4
Different Frequency
ps
tjitter(cc) Cycle-to-Cycle Jitter; NOTE 4
ps
fVCO
PLL VCO Lock Range
Output Rise Time; NOTE 3
Output Duty Cycle
220
0.1
45
MHz
ns
tR/tF
0.8V to 2.0V
odc
55
ꢀ
tLOCK
PLL Lock Time
10
ms
ns
tPZL, tPZH
tPLZ, tPHZ
Output Enable Time; NOTE 3
Output Disable Time; NOTE 3
2
2
10
8
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.
NOTE: All parameters measured at fMAX unless noted otherwise.
NOTE 1: 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: These parameters are guaranteed by characterization. Not tested in production.
NOTE 4: This parameter is defined in accordance with JEDEC Standard 65.
ICS87931BYI REVISION A AUGUST 25, 2010
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©2010 Integrated Device Technology, Inc.
ICS87931I
LOW SKEW, 1-TO-6, LVCMOS/LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER
PARAMETER MEASUREMENT INFORMATION
1.65V 5ꢀ
VDDA
SCOPE
VDDA,
VDDO
nCLK0
Qx
LVCMOS
VPP
VCMR
Cross Points
CLK0
GND
GND
-1.65V 5ꢀ
3.3V OUTPUT LOAD AC TEST CIRCUIT
DIFFERENTIAL INPUT LEVEL
VDDO
VDDO
VDDO
VDDO
2
Qx
Qy
2
2
2
QAx,
QBx,
QCx
➤
➤
tcycle n
tcycle n+1
➤
➤
VDDO
2
tjit(cc) = tcycle n – tcycle n+1
1000 Cycles
tsk(o)
OUTPUT SKEW
CYCLE-TO-CYCLE JITTER
2V
2V
VDD
0.8V
0.8V
2
CLK1
QAx, QBx, QCx
tR
tF
nCLK0
CLK0
VDDO
OUTPUT RISE/FALL TIME
2
EXT_FB
VDDO
2
QAx, QBx, QCx
tPW
tPERIOD
tPW
x 100ꢀ
odc =
tPERIOD
PROPAGATION DELAY
odc & tPERIOD
ICS87931BYI REVISION A AUGUST 25, 2010
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©2010 Integrated DeviceTechnology, Inc.
ICS87931I
LOW SKEW, 1-TO-6, LVCMOS/LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER
APPLICATION INFORMATION
WIRING THE DIFFERENTIAL INPUT TO ACCEPT SINGLE ENDED LEVELS
impedance. For most 50 applications, R3 and R4 can be 100Ω.
Figure 2 shows how a differential input can be wired to accept
single ended levels.The reference voltageVREF =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 VREF in 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
VREF 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
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 andVIH 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. SINGLE ENDED SIGNAL DRIVING DIFFERENTIAL INPUT
ICS87931BYI REVISION A AUGUST 25, 2010
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©2010 Integrated Device Technology, Inc.
ICS87931I
LOW SKEW, 1-TO-6, LVCMOS/LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER
DIFFERENTIAL CLOCK INPUT INTERFACE
The CLK /nCLK accepts LVDS, LVPECL, LVHSTL, SSTL, HCSL
and other differential signals. Both differential signals must meet
the VPP and VCMR input requirements. Figures 3A to 3F show inter-
face examples for the CLK/nCLK input driven by the most com-
mon driver types. The input interfaces suggested here are ex-
amples only. Please consult with the vendor of the driver compo-
nent 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
3.3V
3.3V
1.8V
Zo = 50Ω
Zo = 50Ω
CLK
CLK
Zo = 50Ω
nCLK
Zo = 50Ω
Differential
Input
nCLK
LVPECL
Differential
Input
R1
50
R2
50
LVHSTL
R1
50
R2
50
IDT
HiPerClockS
LVHSTL Driver
R2
50
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
3.3V
3.3V
3.3V
3.3V
3.3V
R3
125
R4
125
Zo = 50Ω
Zo = 50Ω
Zo = 50Ω
CLK
CLK
R1
100
nCLK
nCLK
Zo = 50Ω
Differential
Input
Receiver
LVPECL
LVDS
R1
84
R2
84
FIGURE 2C. CLK/nCLK INPUT DRIVEN BY A
3.3V LVPECL DRIVER
FIGURE 3D. CLK/nCLK INPUT DRIVEN BY A
3.3V LVDS DRIVER
2.5V
2.5V
3.3V
3.3V
2.5V
R3
R4
120
120
Zo = 50Ω
*R3
*R4
33
33
Zo = 60Ω
Zo = 60Ω
CLK
CLK
Zo = 50Ω
nCLK
nCLK
Differential
Input
Differential
Input
SSTL
HCSL
R1
50
R2
50
R1
120
R2
120
*Optional – R3 and R4 can be 0Ω
FIGURE 3F. CLK/nCLK INPUT DRIVEN BY A
2.5V SSTL DRIVER
FIGURE 3E. CLK/nCLK INPUT DRIVEN BY A
3.3V HCSL DRIVER
ICS87931BYI REVISION A AUGUST 25, 2010
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©2010 Integrated DeviceTechnology, Inc.
ICS87931I
LOW SKEW, 1-TO-6, LVCMOS/LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER
SCHEMATIC EXAMPLE
Figure 4A shows a schematic example of using an ICS87931I. It is power pin. The low pass filter R7, C11 and C16 for clean analog
recommended to have one decouple capacitor per power pin. Each supply should also be located as close to the VDDA pin as possible.
decoupling capacitor should be located as close as possible to the
R1
43
Zo = 50
VDD
VDD
R7
10 - 15
Receiv er
VDD
U1
C16
10u
C11
0.01u
1
24
23
22
21
20
19
18
17
nc
GND
QB0
QB1
VDDO
3.3V
2
3
4
5
6
7
8
R3
1K
R4
1K
VDDA
POWER_DN
CLK1
nMR
CLK0
nCLK0
GND
POWER_DN
Zo = 50 Ohm
Zo = 50 Ohm
EXTFB_SEL
CLK_SEL
PLL_SEL
nc
R5
1K
3.3V PECL Driver
R8
50
R9
50
ICS87931I
Logic Input Pin Examples
Set Logic
R10
50
Set Logic
Input to
'0'
VDD
VDD
Zo = 50
Input to
'1'
R2
43
RU1
1K
RU2
Not Install
Receiv er
To Logic
Input
pins
To Logic
Input
pins
(U1-13)
C1
(U1-21)
(U1-28)
VDD
RD1
RD2
1K
C2
0.1uF
C3
0.1uF
VDD=3.3V
Not Install
0.1uF
SP = Space (i.e. not intstalled)
FIGURE 4A. ICS87931I SCHEMATIC EXAMPLE
ICS87931BYI REVISION A AUGUST 25, 2010
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©2010 Integrated Device Technology, Inc.
ICS87931I
LOW SKEW, 1-TO-6, LVCMOS/LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER
The following component footprints are used in this layout
example:
might be restricted by the available space on the board and the
component location. While routing the traces, the clock signal traces
should be routed first and should be locked prior to routing other
signal traces.
All the resistors and capacitors are size 0603.
POWER AND GROUNDING
• The differential 50Ω output traces should have same
Place the decoupling capacitors as close as possible to the power
pins. If space allows, placement of the decoupling capacitor on the
component side is preferred. This can reduce unwanted induc-
tance between the decoupling capacitor and the power pin caused
by the via.
length.
• Avoid sharp angles on the clock trace. Sharp angle
turns cause the characteristic impedance to change
on
the transmission lines.
• Keep the clock traces on the same layer. Whenever pos-
sible, avoid placing vias on the clock traces. Placement
of vias on the traces can affect the trace characteristic
impedance and hence degrade signal integrity.
Maximize the power and ground pad sizes and number of vias
capacitors. This can reduce the inductance between the power
and ground planes and the component power and ground pins.
• To prevent cross talk, avoid routing other signal traces in
parallel with the clock traces. If running parallel traces is
unavoidable, allow a separation of at least three trace
widths between the differential clock trace and the other
signal trace.
The RC filter consisting of R7, C11, and C16 should be placed as
close to the VDDA pin as possible.
CLOCKT RACES ANDT ERMINATION
Poor signal integrity can degrade the system performance or cause
system failure. In synchronous high-speed digital systems, the clock
signal is less tolerant to poor signal integrity than other signals.
Any ringing on the rising or falling edge or excessive ring back can
cause system failure. The shape of the trace and the trace delay
• Make sure no other signal traces are routed between the
clock trace pair.
• The series termination resistors should be located as
close to the driver pins as possible.
50 Ohm
Trace
GND
VCC
C3
R1
VCCA
U1
VIA
Pin 1
Other
signals
C2
R2
C1
50 Ohm
Trace
FIGURE 4B. PCB BOARD LAYOUT FOR ICS87931I
ICS87931BYI REVISION A AUGUST 25, 2010
11
©2010 Integrated DeviceTechnology, Inc.
ICS87931I
LOW SKEW, 1-TO-6, LVCMOS/LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER
RELIABILITY INFORMATION
TABLE 8. θJAVS. AIR FLOW TABLE
θJA byVelocity (Linear Feet per Minute)
0
200
55.9°C/W
42.1°C/W
500
50.1°C/W
39.4°C/W
Single-Layer PCB, JEDEC Standard Test Boards
Multi-Layer PCB, JEDEC Standard Test Boards
67.8°C/W
47.9°C/W
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 ICS87931I is: 2942
ICS87931BYI REVISION A AUGUST 25, 2010
12
©2010 Integrated Device Technology, Inc.
ICS87931I
LOW SKEW, 1-TO-6, LVCMOS/LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER
PACKAGE OUTLINE - Y SUFFIX
TABLE 9. PACKAGE DIMENSIONS
JEDEC VARIATION
ALL DIMENSIONS IN MILLIMETERS
BBA
SYMBOL
MINIMUM
NOMINAL
MAXIMUM
N
A
32
--
--
--
1.60
0.15
1.45
0.45
0.20
A1
A2
b
0.05
1.35
0.30
0.09
1.40
0.37
c
--
D
9.00 BASIC
7.00 BASIC
5.60 Ref.
9.00 BASIC
7.00 BASIC
5.60 Ref.
0.80 BASIC
0.60
D1
D2
E
E1
E2
e
L
0.45
0.75
θ
--
0°
7°
ccc
--
--
0.10
Reference Document: JEDEC Publication 95, MS-026
ICS87931BYI REVISION A AUGUST 25, 2010
13
©2010 Integrated DeviceTechnology, Inc.
ICS87931I
LOW SKEW, 1-TO-6, LVCMOS/LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER
TABLE 10. ORDERING INFORMATION
Part/Order Number
87931BYI
Marking
Package
Packaging
Tray
Temperature
-40°C to 85°C
-40°C to 85°C
-40°C to 85°C
-40°C to 85°C
ICS87931BI
ICS87931BI
32 Lead LQFP
87931BYIT
32 Lead LQFP
1000 Tape & Reel
Tray
87931BYILF
87931BYILFT
ICS87931BYIL
ICS87931BYIL
Lead-Free, 32 Lead LQFP
Lead-Free, 32 Lead LQFP
1000 Tape & Reel
While the information presented herein has been checked for both accuracy and reliability, Integrated Device Technology, Incorporated (IDT) assumes no responsibility for either its use or for 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 ranges, 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.
ICS87931BYI REVISION A AUGUST 25, 2010
14
©2010 Integrated Device Technology, Inc.
ICS87931I
LOW SKEW, 1-TO-6, LVCMOS/LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER
REVISION HISTORY SHEET
Description of Change
Rev
Table
Page
Date
T7
6
8
9
AC Characteristics Table - added thermal note.
Updated Wiring the Differential Input to Accept Single-Ended Levels section.
Updated Differential Clock Input Interface section.
Ordering Information Table - added LF part numbers and marking. Deleted
"ICS" prefix from Part/Order Number column.
Changed from ICS to IDT format header/foot.
Input Reference Frequency Table - added to table description
"EXTFB_SEL = 0".
A
2/23/10
T10
T4B
14
3
A
8/25/10
ICS87931BYI REVISION A AUGUST 25, 2010
15
©2010 Integrated DeviceTechnology, Inc.
ICS87931I
LOW SKEW, 1-TO-6, LVCMOS/LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER
www.IDT.com
6024 Silver Creek Valley Road
San Jose, CA 95138
Sales
Techical Support
netcom@idt.com
+480-763-2056
800-345-7015 (inside USA)
+408-284-8200 (outside USA)
Fax: 408-284-2775
www.IDT.com/go/contactIDT
DISCLAIMER Integrated Device Technology, Inc. (IDT) and its subsidiaries reserve the right to modify the products and/or specifications described herein at any time and at IDT’s sole discretion.All information
in this document, including descriptions of product features and performace, is subject to change without notice. Performance specifications and the operating parameters of the described products are
determined in the independent state and are not guaranteed to perform the same way when installed in customer products. The information contained herein is provided without representation or warranty of any
kind, whether express or implied, including, but not limited to, the suitablity of IDT’s products for any particular purpose, an implied warranty of merchantability, or non-infringement of the intellectual property
rights of others. This document is presented only as a guide and does not convey any license under intellectual property rights of IDT or any third parties.
IDT’s products are not intended for use in life support systems or similar devices where the failure or malfunction of an IDT product can be reasonably expected to significantly affect the health or safety of users.
Anyone using an IDT product in such a manner does so at their own risk, absent an express, written agreement by IDT.
Integrated Device Techology, IDT and the IDT logo are registered trademarks of IDT. Other trademarks and service marks used herein, including protected names, logos and designs, are the property of IDT or
their respective third party owners.
Copyright 2010. All rights reserved.
ICS87931BYI REVISION A AUGUST 25, 2010
16
©2010 Integrated Device Technology, Inc.
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