PERICOM PI6C484321FB

PI6C484321
260MHz Crystal-to-3.3V Differential
LVPECL Frequency Synthesizer
Product Features
Description
• Dual differential 3.3V LVPECL outputs
• Selectable crystal oscillator interface or LVCMOS/LVTTL
TEST_CLK
• Output frequency range: 53.33MHz to 366.67MHz
• Crystal input frequency range: 14MHz to 40MHz
• TEST_CLK freqeuncy range: 10MHz to 50MHz
• VCO range: 320MHz to 1.1GHz
• Parallel or serial interface for programming counter and
output dividers
• RMS period jitter: 3ps (typical)
• 3.3V supply voltage
• 0°C to 70°C ambient operating temperature
• Packages (Pb-free & Green available):
- 32-pin LQFP (FB)
The PI6C484321 is a dual output, 3.3V LVPECL Frequency Synthesizer using crystal as the input source. The input source is can
be selected from either LVTTL/LVCMOS level input (TEST_CLK
pin) or crystal inputs. The VCO operates at a frequency range of
320MHz to 1.1GHz. The VCO frequency is programmed in steps
equal to the value of the input reference or crystal frequency. The
VCO and output frequency can be programmed through a simple
2-wire serial interface or through 11-bit parallel interface. The low
phase noise characteristics of the PI6C484321 make it an ideal
clock source for Fibre Channel 1 (FC1), Fibre Channel 2 (FC2), 10
Gigabit Fibre Channel (10GFC), Gigabit Ethernet and 10 Gigabit
Ethernet (10GbE) applications.
Pin Configuration
Block Diagram
VCO_SEL
XTAL1
nP_LOAD
M0
M1
32 31 30 29 28 27 26 25
XTAL2
PLL
PHASE DETECTOR
MR
VCO
?÷M
0
1
FOUT0
nFOUT0
FOUT1
nFOUT1
XTAL2
2
23
TEST_CLK
M7
3
22
XTAL_SEL
M8
4
21
VCCA
N0
5
20
S_LOAD
N1
6
19
S_DATA
nc
7
18
S_CLOCK
VEE
8
17
MR
9 10 11 12 13 14 15 16
VEE
nFOUT0
FOUT0
VCCO
nFOUT1
M0:M8
24
M6
FOUT1
TEST
1
VCC
CONFIGURATION
INTERFACE
LOGIC
÷3
÷4
÷5
÷6
M5
TEST
S_LOAD
S_DATA
S_CLOCK
nP_LOAD
M2
1
M3
OSC
M4
0
XTAL1
VCO_SEL
XTAL_SEL
TEST_CLK
N0:N1
1
PS8765A
08/01/05
PI6C484321
260MHz Crystal-to-3.3V Differential
LVPECL Frequency Synthesizer
Functional Description
The following functional description describes operations using
a 25MHz crystal. Valid PLL loop divider values for different
crystal or input frequencies are defined in the Input Frequency
Characteristics, Table 5, NOTE 1.
M divider is defined as follows:
fVCO = fxtal x M
The M value and the required values of M0 through M8 are
shown in Table 3B to program the VCO Frequency Function
Table. The output frequency is defined as follows:
The PI6C484321 features a fully integrated PLL, thus requires
no external components for setting the loop bandwidth. A fundamental crystal is the input to the internal oscillator. The output
of the oscillator is fed into the phase detector. A 25MHz crystal
provides a 25MHz reference frequency to the phase detector. The
actual VCO range of the PLL is 320MHz to 1.1GHz. The output
of the M divider is used by the phase detector.
fOUT = fVCO = fxtal 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
register 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
follows:
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 illegal 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 feature that selects the M divider and N output divider supports two modes: parallel and serial modes. Figure
1 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 relationship between the VCO frequency, the crystal frequency and the
TEST Output
T1
T0
0
0
LOW
0
1
S_Data
1
0
Output of M divider
1
1
CMOS Fout
SERIAL LOADING
S_CLOCK
S_DATA
T1
t
S
S_LOAD
T0
*NULL
N1
N0
M8
M7
M6
M5
M4
M3
M2
M1
M0
t
H
nP_LOAD
t
S
PARALLEL LOADING
M0:M8, N0:N1
M, N
nP_LOAD
t
S
t
H
Time
Parallel & Serial Load Operations
2
PS8765A
08/01/05
PI6C484321
260MHz Crystal-to-3.3V Differential
LVPECL Frequency Synthesizer
Pin Description
Number
Name
Type
Description
1
M5
Input
Pullup
2, 3, 4, 28,
29, 30, 31,
32
M6, M7, M8,
M0, M1, M2,
M3, M4
Input
Pulldown
5, 6
N0, N1
Input
Pulldown
7
nc
unused
No connect
8, 16
VEE
Power
Negative supply pins
9
TEST
Output
Test output. ACTIVE in the serial mode of operation. Output driven
LOW in parallel mode. LVCMOS interface levels
10
VCC
Power
Positive supply pin
11, 12
FOUT1,
nFOUT2
Output
Differential output for the synthesizer. LVPECL interface levels
13
VCCO
Power
Output supply pin
14, 15
FOUT0,
nFOUT0
Output
Differential output for the synthesizer. LVPECL interface levels
M divider input. Data latched on LOW-to-HIGH transition of nP_
LOAD input. LVCMOS / LVTTL interface levels
Determines N output divider value as defined in Table 3C Function
table. LVCMOS / LVTTL interface levels
17
MR
Input
Pulldown
Active High Master reset. When logic HIGH, the internal dividers are
reset causing the true outputs FOUTx to go low and the inverted 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.
18
S_CLOCK
Input
Pulldown
Clocks in serial data present at S_DATA input into the shift register on
the rising edge of S_CLOCK. LVCMOS / LVTTL interface levels.
19
S_DATA
Input
Pulldown
Shirft register serial input. Data sampled on the rising edge of
S_CLOCK. LVCMOS / LVTTL interface levels.
20
S_LOAD
Input
Pulldown
Control transition of data from shift register into the dividers.
LVCMOS / LVTTL interface levels
21
VCCA
Power
22
XTAL_SEL
Input
Pullup
23
TEST_CLK
Input
Pulldown
24, 25
XTAL1, XTAL2
Input
26
nP_LOAD
Input
Pulldown
27
VCO_SEL
Input
Pullup
Notes
1.
Analog supply pin
Selects between crystals or test inputs as the PLL reference source.
Selects XTAL inputs when HIGH. Selects TEST_CLK when LOW.
LVCMOS / LVTTL interface levels.
Test clock input. LVCMOS / LVTTL interface levels
Crystal oscillator inputs
Parallel load input to determine when data present at M8:M0 is loaded
into M divider, and when data is present at N1:N0 sets the N output
divider value. LVCMOS / LVTTL interface levels.
Controls the clock synthesizer to be in PLL or bypass mode.
LVCMOS /LVTTL interface levels
Pullup and Pulldown refer to internal input resistors. See Pin characterstics Table for typical values.
3
PS8765A
08/01/05
PI6C484321
260MHz Crystal-to-3.3V Differential
LVPECL Frequency Synthesizer
Pin Characteristics
Symbol
Parameter
Min.
Typ.
CIN
Input capacitance
4
RPULLUP
Input Pullup resistor
51
RPULLDOWN
Input Pulldown resistor
51
Max.
Units
pF
kΩ
Parallel and Serial Modes Function Table
Inputs
nP_LOAD
M
N
S_LOAD
H
X
X
X
X
X
X
Reset mode, forces outputs LOW.
L
L
Data
Data
X
X
X
Data on M and N input passed directly to the M
divider. TEST output forced LOW
L
↑
Data
Data
L
X
X
Data is latched into input registers and remains
loaded until next LOW transition or until a serial
event occurs
L
H
X
X
L
↑
Data
Serial input mode. Shift register is loaded with data
on S-DATA on each rising edge of S_CLOCK
L
H
X
X
↑
L
Data
Contents of the shift register are passed to the M
divider
L
H
X
X
↓
L
Data
M divider and N output divider values are latched
L
H
X
X
L
X
X
Parallel or serial input do not affect shift registers
L
H
X
X
Notes:
S_CLOCK S_DATA
Conditions
MR
H
↑
Data
S_Data passed directly to M divider as it is clocked
L = Low, H = High, X = Don't care, ↑ = Rising Edge, and ↓ = Falling edge Transition
Programmable VCO Frequency Example Based On 25MHz input
256
128
64
32
16
8
4
2
1
M8
M7
M6
M5
M4
M3
M2
M1
M0
25
0
0
0
0
1
1
0
0
1
650
26
0
0
0
0
1
1
0
1
0
675
27
0
0
0
0
1
1
0
1
1
775
31
0
0
0
0
1
1
1
1
1
VCO Freq.
M Divider
625
Programmable Output Divider FunctionTable
Inputs
N1
N0
N Divider
Value
0
0
0
Output Frequency (MHz)
Min.
Max.
3
106.67
366.67
1
4
80
275
1
0
5
64
220
1
1
6
53.33
183.33
Notes:
Fout_min = Fvco_min / N = 320MHz / N
Fout_max = Fvco_max /N = 1100MHz / N
4
PS8765A
08/01/05
PI6C484321
260MHz Crystal-to-3.3V Differential
LVPECL Frequency Synthesizer
Absolute Maximum Ratings
Supply voltage, VCC ............................................................ 4.6V
Inputs, VI .................................................... -0.5V to VCC + 0.5V
Outputs, VO (LVPECL)............................-0.5V to VDDO + 0.5V
Outputs, IO (LVCMOS)
Continuous current .......................................................... 50mA
Surge current ................................................................. 100mA
Package Thermal Impedance, Theta JA ......... 47.9ºC/W (0 lfpm)
Notes:
1. 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
effect product reliability.
Storage Temperature, TSTG ................................-65º C to 150ºC
Commonly Used Configuration Function Table
Input
Output Frequency (MHz)
Crystal (MHz)
M Divider Value
N Divider Value
19.44
32
4
155.52
19.53125
32
4
156.25
25
25
4
156.25
25
25
5
125
25.50
25
3
212.50
25.50
25
4
159.375
25.50
25
6
106.25
38.88
16
4
155.52
20
75
20
83.33
5
PS8765A
08/01/05
PI6C484321
260MHz Crystal-to-3.3V Differential
LVPECL Frequency Synthesizer
LVCMOS / LVTTL DC Characteristics, VCC = VCCA = VCCO = 3.3V ±5%, TA = 0°C to 70°C
Symbol
VIH
Parameter
Input High Voltage
VIL
Input Low Voltage
IIH
Input High Current
IIL
Input Low Current
Min.
Typ.
Max.
VCO_SEL, XTAL_SEL, MR,
S_LOAD, nP_LOAD, N0:N1,
S_DATA, S_CLOCK, M0:M8
2
VCC +0.3V
TEST_CLK
2
VCC +0.3V
VCO_SEL, XTAL_SEL, MR,
S_LOAD, nP_LOAD, N0:N1,
S_DATA, S_CLOCK, M0:M8
-0.3
0.8
TEST_CLK
-0.3
1.3
M0-M4, M6-M8, N0, N1, MR,
S_CLOCK, TEST_CLK, S_DATA,
S_LOAD, nP_LOAD
VCC = VIN =
3.465V
150
M5, XTAL_SEL, VCO_SEL
VCC = VIN =
3.465V
5
VCC = 3.465V,
VIN = 0V
-5
M5, XTAL_SEL, VCO_SEL
VCC = 3.465V,
VIN = 0V
-150
Output High Voltage
TEST(1)
VOL
Output Low Voltage
TEST(1)
Units
V
µA
M0-M4, M6-M8, N0, N1, MR,
S_CLOCK, TEST_CLK, S_DATA,
S_LOAD, nP_LOAD
VOH
Notes
1.
Test Condition
2.6
0.5
V
Outputs terminated with 50Ω to VCC/2. See Parameters Measurement Information table, 3.3V Output Load Test Circuit Figure.
Power Supply DC Characteristics, VCC = VCCA = VCCO = 3.3V ±5%, TA = 0°C to 70°C
Symbol
Parameter
Min.
Typ.
Max.
VCC
Positive supply voltage
3.135
3.3
3.465
VCCA
Analog supply voltage
3.135
3.3
3.465
VCCO
Output supply voltage
3.135
3.3
3.465
IEE
Power supply current
180
ICCA
Analog supply current
30
Units
V
mA
LVPECL DC Characteristics, VCC = VCCA = VCCO = 3.3V ±5%, TA = 0°C to 70°C
Symbol
Parameter
VOH
Output high
VOL
Output low
VSWING
Notes
1.
Test Condition
voltage(1)
voltage(1)
Peak-to-Peak output voltage swing
Min.
Typ.
Max.
VCCO - 1.4
VCCO -1.0
VCCO -2.0
VCCO -1.7
0.6
1.0
Units
V
Outputs terminated with 50Ω to VCC -2V. See Parameter Measurement Section, 3.3V output load test circuit.
6
PS8765A
08/01/05
PI6C484321
260MHz Crystal-to-3.3V Differential
LVPECL Frequency Synthesizer
Input Frequency Characteristics, VCC = VCCA = VCCO = 3.3V±5%, TA 0°C to 70°C
Symbol
Parameter
Test Condition
Min.
TEST_CLK (1)
fIN
Input Frequency
XTAL,
XTAL2(1)
Typ.
Max.
14
40
14
40
S_CLOCK
Notes
1.
Units
MHz
50
For the input crystal and TEST_CLK frequency range, the M value must be set for the VCO to operate with in the 200MHz to 700MHz
range. Using minimum input frequency of 12MHz, valid values of M are 17 ≤ M ≤ 58. Using the maximun frequency of 25MHz, valid
values of M are 8 ≤ M ≤ 28.
Crystal Characteristics
Parameter
Test Condition
Min.
Max.
Units
40
MHz
Equivalent Series resistance (ESR)
50
Ω
Shunt Capacitance
7
pF
Mode of Oscillation
Typ.
Fundamental
Frequency
14
AC Characteristics, VCC = VCCA = VCCO = 3.3V ±5%, TA = 0°C to 70°C
Symbol
FOUT
tjit(per)
tsk(o)
Parameter
Test Condition
Output frequency
Period jitter,
Min.
Typ.
103.3
RMS(1, 3)
3
Output skew(2, 3)
Max.
Units
260
MHz
5
ps
15
ps
tR
Output rise time
20% to 80%
200
700
tF
Output fall time
20% to 80%
200
700
tS
tH
Setup time
Hold time
Mx, Nx to nP_LOAD
5
S_DATA to S_CLOCK
5
S_CLOCK to S_LOAD
5
Mx, Nx to nP_LOAD
5
S_DATA to S_CLOCK
5
S_CLOCK to S_LOAD
5
45
odc
tLOCK
PLL lock time
ps
ns
55
%
1
ms
Notes:
1.
Jitter performance using XTAL inputs.
2.
Defined as skew between outputs with the same supply voltage and with equal load conditions. Measured at the output
differential cross points.
3.
This parameter is defined in accordance with JEDEC standard 65
7
PS8765A
08/01/05
PI6C484321
260MHz Crystal-to-3.3V Differential
LVPECL Frequency Synthesizer
Paramater Measurement Information
2V
VCC,
VCCA,
VCCO
Qx
SCOPE
nFOUTx
FOUTx
LVPECL
nFOUTy
nQx
VEE
FOUTy
tsk(o)
-1.3V ± 0.165V
3.3V Output Load Test Circuit
Output Skew
VOH
nFOUTx
FOUTx
VREF
1
2
3
4
6
Pulse Width
t
VOL
contains 68.26% of all measurements
contains 95.4% of all measurements
contains 99.73% of all measurements
contains 99.99366% of all measurements
contains (100-1.973x10-7)% of all measurements
odc =
t PW
t PERIOD
Histogram
Reference Point
PERIOD
Mean Period
(Trigger Edge)
(First edge after trigger)
Period Jitter
Output Duty Cycle/Pulse Width/Period
80%
80%
VSW I N G
Clock
Outputs
20%
20%
tF
tR
Output Rise/Fall Time
8
PS8765A
08/01/05
PI6C484321
260MHz Crystal-to-3.3V Differential
LVPECL Frequency Synthesizer
Packaging Mechanical: 32-pin LQFP (FB)
9.00 BSC
.354
Square
Square
7.00
BSC
0.09
0.20
.004
.008
GAUGE PLANE
0.25 mm
.276
1.60 Max.
.063
0°
7°
0.45 .018
0.75 .030
1.00 REF
.039
.004
0.10
Seating Plane
0.30 .012
0.45 .018
0.80 BSC
.032
0.05
0.15
.002
.006
1.35
1.45
.053
.057
X.XX DENOTES DIMENSIONS
X.XX IN MILLIMETERS
Ordering Information
Ordering Code
Package Code
PackageType
PI6C484321FB
FB
32-Pin LQFP
PI6C484321FBE
FB
Pb-free & Green, 32-Pin LQFP
Notes:
1. Thermal characteristics can be found on the company web site at http://www.pericom.com/packaging/
Pericom Semiconductor Corporation • 1-800-435-2336 • http://www.pericom.com
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PS8765A
08/01/05