ICS8432DI-101 [ICSI]
700MHZ, DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER; 700MHZ ，差分至3.3V的LVPECL频率合成器
| 型号： | ICS8432DI-101 |
| 厂家： | 
INTEGRATED CIRCUIT SOLUTION INC |
| 描述： | 700MHZ, DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER |
| 文件： | 总18页 (文件大小：168K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
ICS8432I-101
700MHZ,
DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
Integrated
Circuit
Systems, Inc.
GENERAL DESCRIPTION
FEATURES
The ICS8432I-101 is a general purpose, dual out- • Dual differential 3.3V LVPECL outputs
ICS
put Differential-to-3.3V LVPECL high frequency
• Selectable CLK, nCLK or LVCMOS/LVTTLTEST_CLK
HiPerClockS™
synthesizer and a member of the HiPerClockS™
family of High Performance Clock Solutions from
ICS. The ICS8432I-101 has a selectable
• TEST_CLK can accept the following input levels:
LVCMOS or LVTTL
TEST_CLK or CLK, nCLK inputs.TheTEST_CLK input accepts
LVCMOS or LVTTL input levels and translates them to 3.3V
LVPECL levels.The CLK, nCLK pair can accept most standard
differential input levels.TheVCO operates at a frequency range
of 250MHz to 700MHz.The VCO frequency is programmed in
steps equal to the value of the input differential or single ended
reference frequency. The VCO and output frequency can be
programmed using the serial or parallel interfaces to the
configuration logic.The low phase noise characteristics of the
ICS8432I-101 makes it an ideal clock source for Gigabit
Ethernet and SONET applications.
• CLK, nCLK pair can accept the following differential
input levels: LVPECL, LVDS, LVHSTL, SSTL, HCSL
• CLK, nCLK orTEST_CLK maximum input frequency: 40MHz
• Output frequency range: 25MHz to 700MHz
• VCO range: 250MHz to 700MHz
• Accepts any single-ended input signal on CLK input
with resistor bias on nCLK input
• Parallel interface for programming counter
and output dividers
• RMS period jitter: 5ps (maximum)
• Cycle-to-cycle jitter: 25ps (maximum)
• 3.3V supply voltage
• -40°C to 85°C ambient operating temperature
• Lead-Free package fully RoHS compliant
BLOCK DIAGRAM
PIN ASSIGNMENT
VCO_SEL
CLK_SEL
TEST_CLK
0
32 31 30 29 28 27 26 25
CLK
nCLK
1
M5
M6
M7
M8
N0
N1
nc
1
2
3
4
5
6
7
8
24
23
22
21
20
19
18
17
CLK
TEST_CLK
CLK_SEL
VCCA
ICS8432I-101
S_LOAD
S_DATA
S_CLOCK
MR
PLL
PHASE DETECTOR
MR
0
VEE
÷1
÷2
÷4
÷8
VCO
FOUT0
nFOUT0
FOUT1
nFOUT1
9
10 11 12 13 14 15 16
÷ M
1
S_LOAD
S_DATA
S_CLOCK
nP_LOAD
CONFIGURATION
INTERFACE
LOGIC
TEST
32-Lead LQFP
7mm x 7mm x 1.4mm package body
M0:M8
N0:N1
Y Package
TopView
8432DYI-101
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REV. A MAY 23, 2005
1
ICS8432I-101
700MHZ,
DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
Integrated
Circuit
Systems, Inc.
FUNCTIONAL DESCRIPTION
NOTE:The functional description that follows describes op-
eration using a 25MHz clock input.Valid PLL loop divider val-
rial event occurs. As a result, the M and N bits can be hardwired
to set the M divider and N output divider to a specific default
ues for different input frequencies are defined in the Input Fre- state that will automatically occur during power-up.The TEST
quency Characteristics, Table 5, NOTE 1.
output is LOW when operating in the parallel input mode. The
relationship between the VCO frequency, the input frequency
and the M divider is defined as follows:
The ICS8432I-101 features a fully integrated PLL and there-
fore requires no external components for setting the loop band-
width. A differential clock input is used as the input to the
fVCO = fIN x M
The M value and the required values of M0 through M8 are
ICS8432-101. This input is fed into the phase detector. A shown in Table 3B, Programmable VCO Frequency Function
25MHz clock input provides a 25MHz phase detector refer- Table.Valid M values for which the PLL will achieve lock for a
25MHz reference are defined as 8 ≤ M ≤ 28. The frequency
ence frequency. The VCO of the PLL operates over a range
of 250MHz to 700MHz. The output of the M divider is also
applied to the phase detector.
fOUT = fVCO = fIN x M
out is defined as follows:
N
N
Serial operation occurs when nP_LOAD is HIGH and S_LOAD is
The phase detector and the M divider force the VCO output LOW. The shift register is loaded by sampling the S_DATA
frequency to be M times the reference frequency by adjust- bits with the rising edge of S_CLOCK. The contents of the shift
register are loaded into the M divider and N output divider when
S_LOAD transitions from LOW-to-HIGH.The M divide and N out-
put divide values are latched on the HIGH-to-LOW transition of
S_LOAD. If S_LOAD is held HIGH, data at the S_DATA input is
passed directly to the M divider and N output divider on each rising
edge of S_CLOCK. The serial mode can be used to
program the M and N bits and test bitsT1 andT0.The internal reg-
istersT0 andT1 determine the state of theTEST output as follows:
ing the VCO control voltage. Note, that for some values of M
(either too high or too low), the PLL will not achieve lock. The
output of the VCO is scaled by a divider prior to being sent to
each of the LVPECL output buffers. The divider provides a
50% output duty cycle.
The programmable features of the ICS8432I-101 support two
input modes to program the PLL M divider and N output divider.
The two input operational modes are parallel and serial. Figure1
shows the timing diagram for each mode. In parallel mode, the
nP_LOAD input is initially LOW.The data on inputs M0 through
M8 and N0 and N1 is passed directly to the M divider and
N output divider. On the LOW-to-HIGH transition of the
nP_LOAD input, the data is latched and the M divider remains
loaded until the next LOW transition on nP_LOAD or until a se-
T1 T0
TEST Output
LOW
0
0
1
1
0
1
0
1
S_Data, Shift Register Input
Output of M divider
CMOS Fout
S
ERIAL
LOADING
S_CLOCK
T1
T0 *NULL N1
N0
M8
M7
M6
M5
M4 M3
M2
M1
M0
S_DATA
S_LOAD
nP_LOAD
t
t
H
S
t
S
PARALLEL LOADING
M, N
M0:M8, N0:N1
nP_LOAD
t
t
H
S
S_LOAD
Time
FIGURE 1. PARALLEL & SERIAL LOAD OPERATIONS
*NOTE: The NULL timing slot must be observed.
8432DYI-101
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REV. A MAY 23, 2005
2
ICS8432I-101
700MHZ,
DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
Integrated
Circuit
Systems, Inc.
TABLE 1. PIN DESCRIPTIONS
Number
Name
Type
Description
1
M5
Input
Input
Pullup
M divider inputs. Data latched on LOW-to-HIGH transistion
of nP_LOAD input. LVCMOS / LVTTL interface levels.
2, 3, 4
28, 29
M6, M7, M8,
M0, M1,
Pulldown
30, 31, 32
M2, M3, M4
Determines output divider value as defined in Table 3C,
Function Table. LVCMOS / LVTTL interface levels.
5, 6
N0, N1
Input
Pulldown
7
nc
Unused
Power
No connect.
8, 16
VEE
Negative supply pins.
Test output which is ACTIVE in the serial mode of operation. Output
driven LOW in parallel mode. LVCMOS / LVTTL interface levels.
9
TEST
VCC
Output
Power
10
Core supply pin.
11, 12
13
FOUT1, nFOUT1 Output
VCCO Power
FOUT0, nFOUT0 Output
Differential output for the synthesizer. 3.3V LVPECL interface levels.
Output supply pin.
14, 15
Differential output for the synthesizer. 3.3V LVPECL interface levels.
Active High Master Reset. When logic HIGH, the internal dividers
are reset causing the true outputs FOUTx to go low and the inverted
17
MR
Input
Pulldown outputs nFOUTx to go high. When logic LOW, the internal dividers
and the outputs are enabled. Assertion of MR does not affect loaded
M, N, and T values. LVCMOS / LVTTL interface levels.
Clocks in serial data present at S_DATA input into the shift register
on the rising edge of S_CLOCK. LVCMOS / LVTTL interface levels.
Shift register serial input. Data sampled on the rising edge
of S_CLOCK. LVCMOS / LVTTL interface levels.
18
19
S_CLOCK
S_DATA
Input
Input
Pulldown
Pulldown
Controls transition of data from shift register into the dividers.
LVCMOS / LVTTL interface levels.
20
21
S_LOAD
VCCA
Input
Pulldown
Power
Analog supply pin.
Clock select input. Selects between differential clock input or
TEST_CLK input as the PLL reference source. When HIGH,
selects CLK, nCLK inputs. When LOW, selects TEST_CLK input.
22
CLK_SEL
Input
Pullup
LVCMOS / LVTTL interface levels.
23
24
25
TEST_CLK
CLK
Input
Input
Input
Pulldown Test clock input. LVCMOS / LVTTL interface levels.
Pulldown Non-inverting differential clock input.
nCLK
Pullup
Inverting differential clock input.
Parallel load input. Determines when data present at M8:M0 is
26
nP_LOAD
Input
Pulldown loaded into M divider, and when data present at N1:N0 sets the
N output divider value. LVCMOS / LVTTL interface levels.
Determines whether synthesizer is in PLL or bypass mode.
LVCMOS / LVTTL interface levels.
27
VCO_SEL
Input
Pullup
NOTE: Pullup and Pulldown refer to internal input resistors. See Table 2, Pin Characterisitics, 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
8432DYI-101
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REV. A MAY 23, 2005
3
ICS8432I-101
700MHZ,
DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
Integrated
Circuit
Systems, Inc.
TABLE 3A. PARALLEL AND SERIAL MODE FUNCTION TABLE
Inputs
Conditions
MR nP_LOAD
M
N
S_LOAD S_CLOCK S_DATA
H
X
X
X
X
X
X
Reset. Forces outputs LOW.
Data on M and N inputs passed directly to the
M divider and N output divider. TEST output
forced LOW.
Data is latched into input registers and remains loaded
until next LOW transition or until a serial event occurs.
Serial input mode. Shift register is loaded with data on
S_DATA on each rising edge of S_CLOCK.
Contents of the shift register are passed to the
M divider and N output divider.
L
L
Data Data
Data Data
X
X
X
L
L
L
L
↑
L
L
↑
↓
X
↑
L
L
X
H
H
H
X
X
X
X
X
X
Data
Data
Data
M divider and N output divider values are latched.
L
L
H
H
X
X
X
X
L
X
X
Parallel or serial inputs do not affect shift registers.
S_DATA passed directly to M divider as it is clocked.
H
↑
Data
NOTE: L = LOW
H = HIGH
X = Don't care
↑ = Rising edge transition
↓= Falling edge transition
TABLE 3B. PROGRAMMABLE VCO FREQUENCY FUNCTION TABLE
256
M8
0
128
M7
0
64
M6
0
32
M5
0
16
M4
0
8
M3
1
4
M2
0
2
M1
1
1
M0
0
VCO Frequency
(MHz)
M Divide
250
275
•
10
11
•
0
0
0
0
0
1
0
1
1
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
650
675
700
26
27
28
0
0
0
0
1
1
0
1
0
0
0
0
0
1
1
0
1
1
0
0
0
0
1
1
1
0
0
NOTE 1: These M divide values and the resulting frequencies correspond to differential input or TEST_CLK input frequency
of 25MHz.
TABLE 3C. PROGRAMMABLE OUTPUT DIVIDER FUNCTION TABLE
Inputs
Output Frequency (MHz)
N Divider Value
N1
0
N0
0
Minimum
250
Maximum
700
1
2
4
8
0
1
125
350
1
0
62.5
175
1
1
31.25
87.5
8432DYI-101
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REV. A MAY 23, 2005
4
ICS8432I-101
700MHZ,
DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
Integrated
Circuit
Systems, Inc.
ABSOLUTE MAXIMUM RATINGS
SupplyVoltage, V
4.6V
NOTE: Stresses beyond those listed under Absolute
Maximum Ratings may cause permanent damage to the
CC
Inputs, V
-0.5V to VCC + 0.5V
I
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 Character-
istics is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect product reliability.
Outputs, IO
Continuous Current
Surge Current
50mA
100mA
PackageThermal Impedance, θ
47.9°C/W (0 lfpm)
-65°C to 150°C
JA
StorageTemperature, T
STG
TABLE 4A. POWER SUPPLY DC CHARACTERISTICS, VCC = VCCA = VCCO = 3.3V 5%, TA = -40°C TO 85°C
Symbol Parameter
Test Conditions
Minimum
3.135
Typical
3.3
Maximum Units
VCC
VCCA
VCCO
IEE
Core Supply Voltage
3.465
3.465
3.465
120
V
V
Analog Supply Voltage
Output Supply Voltage
Power Supply Current
Analog Supply Current
3.135
3.3
3.135
3.3
V
mA
mA
ICCA
15
TABLE 4B. LVCMOS / LVTTL DC CHARACTERISTICS, VCC = VCCA = VCCO = 3.3V 5%, TA = -40°C TO 85°C
Symbol Parameter
Test Conditions
Minimum Typical Maximum Units
VCO_SEL, CLK_SEL, MR,
S_LOAD, S_DATA,
S_CLOCK, nP_LOAD,
M0:M8, N0:N1
2
V
CC + 0.3
V
V
V
Input
VIH
High Voltage
TEST_CLK
2
VCC + 0.3
0.8
VCO_SEL, CLK_SEL, MR,
S_LOAD, S_DATA,
S_CLOCK, nP_LOAD,
M0:M8, N0:N1
-0.3
-0.3
Input
VIL
Low Voltage
TEST_CLK
1.3
150
5
V
M0-M4, M6-M8, N0, N1, MR,
S_CLOCK, TEST_CLK,
S_DATA, S_LOAD, nP_LOAD
V
CC = VIN = 3.465V
µA
µA
µA
Input
IIH
High Current
M5, CLK_SEL, VCO_SEL
VCC = VIN = 3.465V
VCC = 3.465V,
M0-M4, M6-M8, N0, N1, MR,
S_CLOCK, TEST_CLK,
S_DATA, S_LOAD, nP_LOAD
-5
V
IN = 0V
VCC = 3.465V,
IN = 0V
Input
IIL
Low Current
M5, CLK_SEL, VCO_SEL
-150
2.6
µA
V
V
VCC = 3.135V,
IOH = -36mA
Output
VOH
TEST
TEST
High Voltage
VCC = 3.135V,
IOL = 36mA
Output
VOL
0.5
V
Low Voltage
8432DYI-101
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REV. A MAY 23, 2005
5
ICS8432I-101
700MHZ,
DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
Integrated
Circuit
Systems, Inc.
TABLE 4C. DIFFERENTIAL DC CHARACTERISTICS, VCC = VCCA = VCCO = 3.3V 5%, TA = -40°C TO 85°C
Symbol Parameter
Test Conditions
Minimum
Typical
Maximum
Units
µA
µA
µA
µA
V
CLK
V
CC = VIN = 3.465V
VCC = VIN = 3.465V
CC = 3.465V, VIN = 0V
150
5
IIH Input High Current
nCLK
CLK
V
-5
-150
IIL
Input Low Current
nCLK
VCC = 3.465V, VIN = 0V
VPP
Peak-to-Peak Input Voltage
Common Mode Input Voltage
0.15
1.3
VCMR
VEE + 0.5
VCC - 0.85
V
NOTE 1: For single ended applications, the maximum input voltage for CLK, nCLK is VCC + 0.3V.
NOTE 2: Common mode voltage is defined as VIH.
TABLE 4D. LVPECL DC CHARACTERISTICS, VCC = VCCA = VCCO = 3.3V 5%, TA = -40°C TO 85°C
Symbol Parameter
Test Conditions
Minimum Typical Maximum Units
VOH
Output High Voltage; NOTE 1
VCCO - 1.4
VCCO - 2.0
0.6
VCCO - 0.9
VCCO - 1.7
1.0
V
V
V
VOL
Output Low Voltage; NOTE 1
VSWING
Peak-to-Peak Output Voltage Swing
NOTE 1: Outputs terminated with 50 Ω to VCCO - 2V.
TABLE 5. INPUT FREQUENCY CHARACTERISTICS, VCC = VCCA = VCCO = 3.3V 5%, TA = -40°C TO 85°C
Symbol Parameter Test Conditions Minimum Typical Maximum Units
TEST_CLK; NOTE 1
14
14
25
25
25
MHz
MHz
MHz
fIN
Input Frequency CLK, nCLK; NOTE 1
S_CLOCK
NOTE 1: For the differential input and TEST_CLK frequency range, the M value must be set for the VCO to operate within
the 250MHz to 700MHz range. Using the minimum input frequency of 14MHz, valid values of M are 18 ≤ M ≤ 50.
Using the maximum frequency of 25MHz, valid values of M are 10 ≤ M ≤ 28.
TABLE 6. AC CHARACTERISTICS, VCC = VCCA = VCCO = 3.3V 5%, TA = -40°C TO 85°C
Symbol Parameter
Test Conditions
Minimum
Typical
Maximum
Units
MHz
ps
FOUT
Output Frequency
31.25
700
25
tjit(cc)
tjit(per)
tsk(o)
tR / tF
Cycle-to-Cycle Jitter; NOTE 1, 3
Period Jitter, RMS; NOTE 1
Output Skew; NOTE 2, 3
Output Rise/Fall Time
fVCO > 350MHz
fOUT > 100MHz
5
ps
15
ps
20% to 80%
200
700
ps
M, N to nP_LOAD
5
ns
tS
Setup Time S_DATA to S_CLOCK
S_CLOCK to S_LOAD
5
ns
5
ns
M, N to nP_LOAD
5
ns
tH
Hold Time
S_DATA to S_CLOCK
S_CLOCK to S_LOAD
5
ns
5
47
ns
odc
tPW
Output Duty Cycle
Output Pulse Width
PLL Lock Time
N > 1
N = 1
53
%
tPERIOD/2 - 150
tPERIOD/2 + 150
1
ps
tLOCK
ms
See Parameter Measurement Information section.
NOTE 1: Jitter performance using XTAL inputs.
NOTE 2: Defined as skew between outputs at the same supply voltage and with equal load conditions.
Measured at the output differential cross points.
NOTE 3: This parameter is defined in accordance with JEDEC Standard 65.
8432DYI-101
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REV. A MAY 23, 2005
6
ICS8432I-101
700MHZ,
DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
Integrated
Circuit
Systems, Inc.
PARAMETER MEASUREMENT INFORMATION
2V
VCC
SCOPE
VCC
,
Qx
VCCA
,
VCCO
nCLK
LVPECL
VEE
VPP
VCMR
Cross Points
CLK
VEE
nQx
-1.3V 0.165V
3.3V OUTPUT LOAD AC TEST CIRCUIT
DIFFERENTIAL INPUT LEVEL
VOH
nFOUTx
FOUTx
VREF
VOL
1σ contains 68.26% of all measurements
2σ contains 95.4% of all measurements
3σ contains 99.73% of all measurements
4σ contains 99.99366% of all measurements
6σ contains (100-1.973x10-7)% of all measurements
➤
➤
tcycle n+1
tcycle n
➤
➤
tjit(cc) = tcycle n –tcycle n+1
1000 Cycles
Histogram
Reference Point
(Trigger Edge)
Mean Period
(First edge after trigger)
PERIOD JITTER
CYCLE-TO-CYCLE JITTER
nFOUTx
FOUTx
80%
tF
80%
tR
VSWING
20%
Clock
Outputs
20%
nFOUTy
FOUTy
tsk(o)
OUTPUT SKEW
OUTPUT RISE/FALL TIME
nFOUTx
FOUTx
tPW
tPERIOD
tPW
odc =
x 100%
tPERIOD
OUTPUT DUTY CYCLE/PULSE WIDTH/PERIOD
8432DYI-101
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REV. A MAY 23, 2005
7
ICS8432I-101
700MHZ,
DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
Integrated
Circuit
Systems, Inc.
APPLICATION INFORMATION
STORAGE AREA NETWORKS
A variety of technologies are used for interconnection of the
elements within a SAN.The tables below list the common appli-
cation frequencies as well as the ICS8432I-101 configurations
used to generate the appropriate frequency.
Table 7. Common SANs Application Frequencies
Reference Frequency to SERDES
(MHz)
Crystal Frequency
(MHz)
Interconnect Technology
Gigabit Ethernet
Fibre Channel
Clock Rate
1.25 GHz
125, 250, 156.25
106.25, 53.125, 132.8125
125, 250
25, 19.53125
16.6015625, 25
25
FC1 1.0625 GHz
FC2 2.1250 GHz
Infiniband
2.5 GHz
Table 8. Configuration Details for SANs Applications
ICS8432I-101
ICS8432I-101
Interconnect
Technology
CLK, nCLK Input
(MHz)
Output Frequency
to SERDES
(MHz)
M & N Settings
M8 M7 M6 M5 M4 M3 M2 M1 M0 N1 N0
25
125
250
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
1
0
0
1
1
1
0
1
1
0
1
1
0
0
1
0
0
0
0
0
0
1
1
0
0
0
0
0
1
1
0
0
0
0
0
0
0
0
0
0
0
1
0
1
1
0
0
0
1
0
1
1
1
1
1
1
0
0
1
0
0
1
0
0
0
1
25
Gigabit Ethernet
25
156.25
156.25
53.125
106.25
132.8125
125
19.53125
25
Fiber Channel 1
Fiber Channel 2
Infiniband
25
16.6015625
25
25
250
POWER SUPPLY FILTERING TECHNIQUES
As in any high speed analog circuitry, the power supply pins
are vulnerable to random noise. The ICS8432I-101 provides
separate power supplies to isolate any high switching
noise from the outputs to the internal PLL.VCC, VCCA, and VCCO
should be individually connected to the power supply
plane through vias, and bypass capacitors should be
used for each pin. To achieve optimum jitter performance,
power supply isolation is required. Figure 2 illustrates how
a 10Ω resistor along with a 10μF and a .01μF bypass
capacitor should be connected to each VCCA pin.
3.3V
VCC
.01μF
.01μF
10Ω
VCCA
10μF
FIGURE 2. POWER SUPPLY FILTERING
8432DYI-101
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REV. A MAY 23, 2005
8
ICS8432I-101
700MHZ,
DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
Integrated
Circuit
Systems, Inc.
WIRING THE DIFFERENTIAL INPUT TO ACCEPT SINGLE ENDED LEVELS
of R1 and R2 might need to be adjusted to position theV_REF in
Figure 3 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
the center of the input voltage swing. For example, if the input
clock swing is only 2.5V andVCC = 3.3V, V_REF should be 1.25V
and R2/R1 = 0.609.
VCC
R1
1K
Single Ended Clock Input
V_REF
CLK
nCLK
C1
0.1u
R2
1K
FIGURE 3. SINGLE ENDED SIGNAL DRIVING DIFFERENTIAL INPUT
TERMINATION FOR LVPECL OUTPUTS
The clock layout topology shown below is a typical termina-
tion for LVPECL outputs.The two different layouts mentioned
are recommended only as guidelines.
designed to drive 50Ω transmission lines. Matched impedance
techniques should be used to maximize operating frequency
and minimize signal distortion. Figures 4A and 4B show two
different layouts which are recommended only as guidelines.
Other suitable clock layouts may exist and it would be rec-
ommended that the board designers simulate to guarantee
compatibility across all printed circuit and clock component
process variations.
FOUT and nFOUT are low impedance follower outputs that
generate ECL/LVPECL compatible outputs.Therefore, termi-
nating resistors (DC current path to ground) or current
sources must be used for functionality. These outputs are
3.3V
Z
o = 50Ω
125Ω
125Ω
FOUT
FIN
Zo = 50Ω
Zo = 50Ω
Zo = 50Ω
FOUT
FIN
50Ω
50Ω
VCC - 2V
1
RTT =
Zo
RTT
((VOH + VOL) / (VCC – 2)) – 2
84Ω
84Ω
FIGURE 4A. LVPECL OUTPUT TERMINATION
FIGURE 4B. LVPECL OUTPUT TERMINATION
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ICS8432I-101
700MHZ,
DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
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DIFFERENTIAL CLOCK INPUT INTERFACE
The CLK /nCLK accepts LVDS, LVPECL, LVHSTL, SSTL, HCSL here are examples only. Please consult with the vendor of the
and other differential signals.BothVSWING and VOH must meet the driver component to confirm the driver termination requirements.
VPP and VCMR input requirements. Figures 5A to 5D show inter- For example in Figure 5A, the input termination applies for ICS
face examples for the HiPerClockS CLK/nCLK input driven by HiPerClockS LVHSTL drivers. If you are using an LVHSTL driver
the most common driver types.The input interfaces suggested from another vendor, use their termination recommendation.
3.3V
3.3V
3.3V
1.8V
Zo = 50 Ohm
CLK
Zo = 50 Ohm
CLK
Zo = 50 Ohm
nCLK
Zo = 50 Ohm
HiPerClockS
Input
LVPECL
nCLK
HiPerClockS
Input
LVHSTL
R1
50
R2
50
ICS
HiPerClockS
R1
50
R2
50
LVHSTL Driver
R3
50
FIGURE 5A. HIPERCLOCKS CLK/NCLK INPUT DRIVEN BY
ICS HIPERCLOCKS LVHSTL DRIVER
FIGURE 5B. HIPERCLOCKS CLK/NCLK INPUT DRIVEN BY
3.3V LVPECL DRIVER
3.3V
3.3V
3.3V
3.3V
Zo = 50 Ohm
3.3V
R3
R4
125
125
LVDS_Driver
Zo = 50 Ohm
Zo = 50 Ohm
CLK
CLK
R1
100
nCLK
Receiver
nCLK
HiPerClockS
Input
Zo = 50 Ohm
LVPECL
R1
84
R2
84
FIGURE 5C. HIPERCLOCKS CLK/NCLK INPUT DRIVEN BY
3.3V LVPECL DRIVER
FIGURE 5D. HIPERCLOCKS CLK/NCLK INPUT DRIVEN BY
3.3V LVDS DRIVER
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ICS8432I-101
700MHZ,
DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
Integrated
Circuit
Systems, Inc.
LAYOUT GUIDELINE
The schematic of the ICS8432I-101 layout example used in The layout in the actual system will depend on the selected com-
this layout guideline is shown in Figure 6A. The ICS8432I-101 ponent types, the density of the components, the density of the
recommended PCB board layout for this example is shown in
Figure 6B.This layout example is used as a general guideline.
traces, and the stack up of the P.C. board.
nCLK
CLK
R7
VCC
U1
10
C11
1
2
3
4
5
6
7
8
24
23
22
21
20
19
18
17
0.01u
C16
10u
M5
M6
M7
M8
N0
N1
nc
CLK
REF_IN
nCLK_SEL
VDDA
S_LOAD
S_DATA
S_CLOCK
MR
XTAL_SEL
VCCA
S_LOAD
S_DATA
S_CLOCK
MR
VEE
Termination A
Termination B
(not shown in
the layout)
VCC
8432-101
IN+
R1
R3
125
125
Zo = 50 Ohm
IN+
IN-
IN-
TL1
Zo = 50 Ohm
R2
50
R1
50
C14
0.1u
C15
0.1u
TL2
R2
84
R4
84
R3
50
FIGURE 6A. SCHEMATIC OF RECOMMENDED LAYOUT
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ICS8432I-101
700MHZ,
DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
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The following component footprints are used in this layout
example: All the resistors and capacitors are size 0603.
system failure. The trace shape and the trace delay might be re-
stricted 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.
POWER AND GROUNDING
Place the decoupling capacitors C14 and C15 as close as pos-
sible to the power pins. If space allows, placing the decoupling
capacitor at the component side is preferred. This can reduce
unwanted inductance between the decoupling capacitor and the
power pin generated by the via.
• The traces with 50Ω transmission linesTL1 and TL2 at
FOUT and nFOUT should have equal delay and run ad-
jacent to each other.Avoid sharp angles on the clock trace.
Sharp angle turns cause the characteristic impedance to
change on the transmission lines.
• Keep the clock trace on same layer.Whenever possible,
avoid any vias on the clock traces. Any via on the trace
can affect the trace characteristic impedance and hence
degrade signal quality.
Maximize the pad size of the power (ground) at the decoupling
capacitor.Maximize the number of vias between power (ground)
and the pads.This can reduce the inductance between the power
(ground) plane and the component power (ground) pins.
• To prevent cross talk, avoid routing other signal traces in
parallel with the clock traces. If running parallel traces is
unavoidable, allow more space between the clock trace
and the other signal trace.
If VCCA shares the same power supply with VCC, insert the RC
filter R7, C11, and C16 in between. Place this RC filter as close
to theVCCA as possible.
• Make sure no other signal trace is routed between the
clock trace pair.
CLOCK TRACES AND TERMINATION
The component placements, locations and orientations should be
arranged to achieve the best clock signal quality.Poor clock signal
quality can degrade the system performance or cause system fail-
ure. In the synchronous high-speed digital system, the clock signal
is less tolerable to poor signal quality than other signals. Any ring-
ing on the rising or falling edge or excessive ring back can cause
The matching termination resistors R1, R2, R3 and R4 should
be located as close to the receiver input pins as possible. Other
termination schemes can also be used but are not shown in this
example.
GND
VCC
U1
PIN 1
VIA
C11
C16
VCCA
R7
Close to the input
pins of the
receiver
R4
R3
TL1N
C15
C14
TL1
R2
R1
TL1, TL2 are 50 Ohm traces and
equal length
FIGURE 6B. PCB BOARD LAYOUT FOR ICS8432I-101
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ICS8432I-101
700MHZ,
DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
Integrated
Circuit
Systems, Inc.
POWER CONSIDERATIONS
This section provides information on power dissipation and junction temperature for the ICS8432I-101.
Equations and example calculations are also provided.
1. Power Dissipation.
The total power dissipation for the ICS8432I-101 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 * 120mA = 416mW
Power (outputs)MAX = 30mW/Loaded Output pair
If all outputs are loaded, the total power is 2 * 30mW = 60mW
Total Power_MAX (3.465V, with all outputs switching) = 416mW + 60mW = 476mW
2. JunctionTemperature.
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 HiPerClockSTM devices is 125°C.
The equation for Tj is as follows: Tj = θJA * Pd_total + TA
Tj = JunctionTemperature
θJA = Junction-to-AmbientThermal Resistance
Pd_total =Total Device Power Dissipation (example calculation is in section 1 above)
TA = AmbientTemperature
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 42.1°C/W perTable 9 below.
Therefore, Tj for an ambient temperature of 85°C with all outputs switching is:
85°C + 0.476W * 42.1°C/W = 105°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 9. THERMAL RESISTANCE θJA FOR 32-PIN LQFP, FORCED CONVECTION
θJA byVelocity (Linear Feet per Minute)
0
200
500
Single-Layer PCB, JEDEC Standard Test Boards
Multi-Layer PCB, JEDEC Standard Test Boards
67.8°C/W
55.9°C/W
50.1°C/W
47.9°C/W
42.1°C/W
39.4°C/W
NOTE: Most modern PCB designs use multi-layered boards.The data in the second row pertains to most designs.
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ICS8432I-101
700MHZ,
DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
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Circuit
Systems, Inc.
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 7.
VCCO
Q1
VOUT
R L
50
VCCO - 2V
FIGURE 7. 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 ofV - 2V.
CCO
•
•
For logic high, VOUT = V
= V
– 0.9V
OH_MAX
CCO_MAX
)
= 0.9V
OH_MAX
(V
- V
CCO_MAX
For logic low, VOUT = V
= V
– 1.7V
OL_MAX
CCO_MAX
)
= 1.7V
OL_MAX
(V
- V
CCO_MAX
Pd_H is power dissipation when the output drives high.
Pd_L is the power dissipation when the output drives low.
))
Pd_H = [(V
– (V
- 2V))/R ] * (V
- V
) = [(2V - (V
- V
- V
/R ] * (V
- V
) =
OH_MAX
CCO_MAX
CCO_MAX
OH_MAX
CCO_MAX
OH_MAX
CCO_MAX
OH_MAX
L
L
[(2V - 0.9V)/50Ω] * 0.9V = 19.8mW
))
Pd_L = [(V
– (V
- 2V))/R ] * (V
- V
) = [(2V - (V
/R ] * (V
- V
) =
OL_MAX
CCO_MAX
CCO_MAX
OL_MAX
CCO_MAX
OL_MAX
CCO_MAX
OL_MAX
[(2V - 1.7V)/50Ω] * 1.7V = 10.2mWL
L
Total Power Dissipation per output pair = Pd_H + Pd_L = 30mW
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ICS8432I-101
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DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
Integrated
Circuit
Systems, Inc.
RELIABILITY INFORMATION
TABLE 10. θJAVS. AIR FLOW TABLE FOR 32 LEAD LQFP
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 ICS8432I-101 is: 3712
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DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
Integrated
Circuit
Systems, Inc.
PACKAGE OUTLINE - Y SUFFIX FOR 32 LEAD LQFP
TABLE 11. 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
D1
D2
E
9.00 BASIC
7.00 BASIC
5.60
E1
E2
e
0.80 BASIC
0.60
L
0.45
0.75
θ
0°
7°
ccc
0.10
Reference Document: JEDEC Publication 95, MS-026
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ICS8432I-101
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DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
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TABLE 12. ORDERING INFORMATION
Part/Order Number
ICS8432DYI-101
Marking
Package
Shipping Packaging
250
Temperature
-40°C to 85°C
-40°C to 85°C
-40°C to 85°C
-40°C to 85°C
ICS8432DI-101
ICS8432DI-101
ICS432DI101L
ICS432DI101L
32 Lead LQFP
ICS8432DYI-101T
ICS8432DYI-101LF
ICS8432DYI-101LFT
32 Lead LQFP
1000 tape & reel
250
32 Lead "Lead-Free" LQFP
32 Lead "Lead-Free" LQFP
1000 tape & reel
NOTE: Parts that are ordered with an "LF" suffix to the part number are the Pb-Free configuration and are RoHS compliant.
The aforementioned trademark, HiPerClockS™ is a trademark of Integrated Circuit Systems, Inc. or its subsidiaries in the United States and/or other countries.
While the information presented herein has been checked for both accuracy and reliability, Integrated Circuit Systems, Incorporated (ICS) 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 and industrial applications. Any other applications such as those requiring high reliability, or other extraordinary environmental requirements are not
recommended without additional processing by ICS. ICS reserves the right to change any circuitry or specifications without notice. ICS does not authorize or warrant any ICS product
for use in life support devices or critical medical instruments.
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ICS8432I-101
700MHZ,
DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
Integrated
Circuit
Systems, Inc.
REVISION HISTORY SHEET
Rev
Table
T12
Page
1
17
Description of Change
Features Section - added Lead-Free bullet.
Ordering Information Table - add Lead-Free parts.
Date
A
5/23/05
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