700MHZ, DIFFERENTIAL-TO-3.3V
LVPECL FREQUENCY SYNTHESIZER
ICS8432-101
G
ENERAL
D
ESCRIPTION
The ICS8432-101 is a general purpose, dual out-
put Differential-to-3.3V LVPECL high frequency
HiPerClockS™
synthesizer and a member of the HiPerClockS™
family of High Performance Clock Solutions from
ICS. The ICS8432-101 has a selectable TEST_CLK
or CLK, nCLK inputs. The TEST_CLK input accepts LVCMOS
or LVTTL input levels and translates them to 3.3V LVPECL lev-
els. The CLK, nCLK pair can accept most standard differen-
tial input levels. The VCO 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 con-
figuration logic. The low phase noise characteristics of the
ICS8432-101 makes it an ideal clock source for Gigabit Ethernet
and SONET applications.
F
EATURES
•
Dual differential 3.3V LVPECL outputs
•
Selectable CLK, nCLK or LVCMOS/LVTTL TEST_CLK
•
TEST_CLK can accept the following input levels:
LVCMOS or LVTTL
•
CLK, nCLK pair can accept the following differential
input levels: LVPECL, LVDS, LVHSTL, SSTL, HCSL
•
CLK, nCLK or TEST_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
•
0°C to 70°C ambient operating temperature
•
Available in both standard (RoHS 5) and lead-free (RoHS 6)
packages
IC
S
B
LOCK
D
IAGRAM
VCO_SEL
CLK_SEL
TEST_CLK
CLK
nCLK
0
P
IN
A
SSIGNMENT
VCO_SEL
nP_LOAD
nCLK
M4
M3
M2
M1
M0
32 31 30 29 28 27 26 25
1
M5
M6
M7
M8
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
TEST
V
CC
FOUT1
nFOUT1
V
CCO
FOUT0
nFOUT0
V
EE
24
23
22
CLK
TEST_CLK
CLK_SEL
V
CCA
S_LOAD
S_DATA
S_CLOCK
MR
PLL
PHASE DETECTOR
MR
÷
M
VCO
0
1
÷1
÷2
÷4
÷8
FOUT0
nFOUT0
FOUT1
nFOUT1
N0
N1
nc
V
EE
ICS8432-101
21
20
19
18
17
S_LOAD
S_DATA
S_CLOCK
nP_LOAD
M0:M8
N0:N1
CONFIGURATION
INTERFACE
LOGIC
TEST
32-Lead LQFP
7mm x 7mm x 1.4mm package body
Y Package
Top View
IDT
™
/ ICS
™
700MHZ, 3.3V LVPECL FREQUENCY SYNTHESIZER
1
ICS8432DY-101 REV. C APRIL 10, 2007
ICS8432-101
700MHZ, DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
F
UNCTIONAL
D
ESCRIPTION
NOTE: The functional description that follows describes opera-
tion using a 25MHz clock input. Valid PLL loop divider values
for different input frequencies are defined in the Input Frequency
Characteristics, Table 5, NOTE 1.
The ICS8432-101 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
ICS8432-101. This input is fed into the phase detector. A 25MHz
clock input provides a 25MHz phase detector reference fre-
quency. 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.
The phase detector and the M divider force the VCO output
frequency to be M times the reference frequency by adjusting
the VCO control voltage. Note, that for some values of M (ei-
ther 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 ICS8432-101 support two in-
put 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 serial
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 state
that will automatically occur during power-up. The TEST output
is LOW when operating in the parallel input mode. The relation-
ship between the VCO frequency, the input frequency and the M
divider is defined as follows:
fVCO = f x M
IN
The M value and the required values of M0 through M8 are
shown in Table 3B, Programmable VCO Frequency Function
Table. Valid M values for which the PLL will achieve lock for a
25MHz reference are defined as 8
≤
M
≤
28. The frequency out
is defined as follows:
fOUT = fVCO = f
IN
x M
N
N
Serial operation occurs when nP_LOAD is HIGH and S_LOAD is
LOW. The shift register is loaded by sampling the S_DATA
bits with the rising edge of S_CLOCK. The contents of the shift reg-
ister are loaded into the M divider and N output divider when S_LOAD
transitions from LOW-to-HIGH. The M divide and N output 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 bits T1 and T0. The internal
registers T0 and T1 determine the state of the TEST output as fol-
lows:
T1 T0
TEST Output
0
0
1
1
0
1
0
1
LOW
S_Data, Shift Register Input
Output of M divider
CMOS Fout
S
ERIAL
L
OADING
S_CLOCK
S_DATA
t
T1
S
T0
H
*
NULL
N1
N0
M8
M7
M6
M5
M4
M3
M2
M1
M0
t
S_LOAD
nP_LOAD
t
S
P
ARALLEL
L
OADING
M0:M8, N0:N1
nP_LOAD
t
S
M, N
t
H
S_LOAD
Time
F
IGURE
1. P
ARALLEL
& S
ERIAL
L
OAD
O
PERATIONS
*NOTE:
The NULL timing slot must be observed.
IDT
™
/ ICS
™
700MHZ, 3.3V LVPECL FREQUENCY SYNTHESIZER
2
ICS8432DY-101 REV. C APRIL 10, 2007
ICS8432-101
700MHZ, DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
T
ABLE
1. P
IN
D
ESCRIPTIONS
Number
1
2, 3 , 4
28, 29
30, 31, 32
5, 6
7
8, 16
9
10
11, 12
13
14, 15
Name
M5
M6, M7, M8,
M0, M1,
M2, M3, M4
N0, N1
nc
V
EE
TEST
V
CC
FOUT1, nFOUT1
V
CCO
FOUT0, nFOUT0
Input
Input
Input
Unused
Power
Output
Power
Output
Power
Output
Type
Pullup
M divider inputs. Data latched on LOW-to-HIGH transistion
Pulldown of nP_LOAD input. LVCMOS / LVTTL interface levels.
Pulldown
Determines output divider value as defined in Table 3C,
Function Table. LVCMOS / LVTTL interface levels.
No connect.
Negative supply pins.
Test output which is ACTIVE in the serial mode of operation. Output
driven LOW in parallel mode. LVCMOS / LVTTL interface levels.
Core supply pin.
Differential output for the synthesizer. 3.3V LVPECL interface levels.
Output supply pin.
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 inver ted
outputs nFOUTx to go high. When logic LOW, the internal dividers
and the outputs are enabled. Asser tion 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.
Controls transition of data from shift register into the dividers.
LVCMOS / LVTTL interface levels.
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.
LVCMOS / LVTTL interface levels.
Test clock input. LVCMOS / LVTTL interface levels.
Non-inver ting differential clock input.
Description
17
MR
Input
Pulldown
18
19
20
21
22
23
24
25
26
27
S_CLOCK
S_DATA
S_LOAD
V
CCA
CLK_SEL
TEST_CLK
CLK
nCLK
nP_LOAD
VCO_SEL
Input
Input
Input
Power
Input
Input
Input
Input
Input
Input
Pulldown
Pulldown
Pulldown
Pullup
Pulldown
Pulldown
Pullup
Inver ting differential clock input.
Parallel load input. Determines when data present at M8:M0 is
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.
Pullup
LVCMOS / LVTTL interface levels.
NOTE:
Pullup
and
Pulldown
refer to internal input resistors. See Table 2, Pin Characterisitics, for typical values.
T
ABLE
2. P
IN
C
HARACTERISTICS
Symbol
C
IN
R
PULLUP
R
PULLDOWN
Parameter
Input Capacitance
Input Pullup Resistor
Input Pulldown Resistor
Test Conditions
Minimum
Typical
4
51
51
Maximum
Units
pF
kΩ
kΩ
IDT
™
/ ICS
™
700MHZ, 3.3V LVPECL FREQUENCY SYNTHESIZER
3
ICS8432DY-101 REV. C APRIL 10, 2007
ICS8432-101
700MHZ, DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
T
ABLE
3A. P
ARALLEL
AND
S
ERIAL
M
ODE
F
UNCTION
T
ABLE
Inputs
Conditions
S_CLOCK
X
X
X
↑
L
L
X
↑
S_DATA
X
X
X
Data
Data
Data
X
Data
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.
M divider and N output divider values are latched.
Parallel or serial inputs do not affect shift registers.
S_DATA passed directly to M divider as it is clocked.
X
X
L
L
↑
↓
L
H
MR
H
L
L
L
L
L
L
nP_LOAD
X
L
↑
H
H
H
H
M
X
Data
Data
X
X
X
X
N
X
Data
Data
X
X
X
X
S_LOAD
L
H
X
X
NOTE: L = LOW
H = HIGH
X = Don't care
↑
= Rising edge transition
↓
= Falling edge transition
T
ABLE
3B. P
ROGRAMMABLE
VCO F
REQUENCY
F
UNCTION
T
ABLE
VCO Frequency
(MHz)
200
225
250
275
•
•
650
675
M Divide
8
9
10
11
•
•
26
27
256
M8
0
0
0
0
•
•
0
0
128
M7
0
0
0
0
•
•
0
0
64
M6
0
0
0
0
•
•
0
0
32
M5
0
0
0
0
•
•
0
0
16
M4
0
0
0
0
•
•
1
1
8
M3
1
1
1
1
•
•
1
1
4
M2
0
0
0
0
•
•
0
0
2
M1
0
0
1
1
•
•
1
1
1
M0
0
1
0
1
•
•
0
1
700
28
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.
T
ABLE
3C. P
ROGRAMMABLE
O
UTPUT
D
IVIDER
F
UNCTION
T
ABLE
Inputs
N1
0
0
1
1
N0
0
1
0
1
N Divider Value
1
2
4
8
Output Frequency (MHz)
Minimum
250
125
62.5
31.25
Maximum
700
35 0
175
87.5
IDT
™
/ ICS
™
700MHZ, 3.3V LVPECL FREQUENCY SYNTHESIZER
4
ICS8432DY-101 REV. C APRIL 10, 2007
ICS8432-101
700MHZ, DIFFERENTIAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
A
BSOLUTE
M
AXIMUM
R
ATINGS
Supply Voltage, V
CC
Inputs, V
I
Outputs, I
O
Continuous Current
Surge Current
Storage Temperature, T
STG
4.6V
-0.5V to V
CC
+ 0.5 V
50mA
100mA
-65°C to 150°C
NOTE: Stresses beyond those listed under Absolute
Maximum Ratings may cause permanent damage to the
device. These ratings are stress specifications only. Functional op-
eration 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 ex-
tended periods may affect product reliability.
Package Thermal Impedance,
θ
JA
47.9°C/W (0 lfpm)
T
ABLE
4A. P
OWER
S
UPPLY
DC C
HARACTERISTICS
,
V
CC
= V
CCA
= V
CCO
= 3.3V±5%, T
A
= 0°C
TO
70°C
Symbol
V
CC
V
CCA
V
CCO
I
EE
I
CCA
Parameter
Core Supply Voltage
Analog Supply Voltage
Output Supply Voltage
Power Supply Current
Analog Supply Current
Test Conditions
Minimum
3.135
3.135
3.135
Typical
3.3
3.3
3.3
Maximum
3.465
3.465
3.465
120
15
Units
V
V
V
mA
mA
T
ABLE
4B. LVCMOS / LVTTL DC C
HARACTERISTICS
,
V
CC
= V
CCA
= V
CCO
= 3.3V±5%, T
A
= 0°C
TO
70°C
Symbol
Parameter
Input
High Voltage
VCO_SEL, CLK_SEL, MR,
S_LOAD, S_DATA,
S_CLOCK, nP_LOAD,
M0:M8, N0:N1
TEST_CLK
VCO_SEL, CLK_SEL, MR,
S_LOAD, S_DATA,
S_CLOCK, nP_LOAD,
M0:M8, N0:N1
TEST_CLK
M0-M4, M6-M8, N0, N1, MR,
S_CLOCK, TEST_CLK,
S_DATA, S_LOAD, nP_LOAD
M5, CLK_SEL, VCO_SEL
M0-M4, M6-M8, N0, N1, MR,
S_CLOCK, TEST_CLK,
S_DATA, S_LOAD, nP_LOAD
M5, CLK_SEL, VCO_SEL
V
OH
V
OL
Output
High Voltage
Output
Low Voltage
TEST
TEST
Test Conditions
Minimum
2
2
-0.3
-0.3
V
CC
= V
IN
= 3.465V
V
CC
= V
IN
= 3.465V
V
CC
= 3.465V,
V
IN
= 0V
V
CC
= 3.465V,
V
IN
= 0V
V
CC
= 3.135V,
I
OH
= -36mA
V
CC
= 3.135V,
I
OL
= 36mA
-5
Typical
Maximum
V
CC
+ 0.3
V
CC
+ 0.3
0.8
1.3
150
5
Units
V
V
V
V
µA
µA
µA
V
IH
V
IL
Input
Low Voltage
I
IH
Input
High Current
I
IL
Input
Low Current
-150
2.6
0.5
µA
V
V
IDT
™
/ ICS
™
700MHZ, 3.3V LVPECL FREQUENCY SYNTHESIZER
5
ICS8432DY-101 REV. C APRIL 10, 2007
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