SIT8008BI-71-33E-33.333300D 数据手册
SiT8008B
Low Power Programmable Oscillator
ow Power, Standard Frequency Oscillator
Features
Applications
Any frequency between 1 MHz and 110 MHz accurate to
6 decimal places
100% pin-to-pin drop-in replacement to quartz-based XO
Excellent total frequency stability as low as ±20 ppm
Operating temperature from -40°C to 85°C. For 125°C and/
or -55°C options, refer to SiT1618, SiT8918, SiT8920
Low power consumption of 3.5 mA typical at 1.8V
Standby mode for longer battery life
Fast startup time of 5 ms
LVCMOS/HCMOS compatible output
Industry-standard packages: 2.0 x 1.6, 2.5 x 2.0, 3.2 x 2.5,
5.0 x 3.2, 7.0 x 5.0 mm x mm
Instant samples with Time Machine II and Field
Programmable Oscillators
RoHS and REACH compliant, Pb-free, Halogen-free and
Antimony-free
For AEC-Q100 oscillators, refer to SiT8924 and SiT8925
Ideal for DSC, DVC, DVR, IP CAM, Tablets, e-Books,
SSD, GPON, EPON, etc.
Ideal for high-speed serial protocols such as: USB,
SATA, SAS, Firewire, 100M / 1G / 10G Ethernet, etc.
Electrical Characteristics
All Min and Max limits are specified over temperature and rated operating voltage with 15 pF output load unless otherwise
stated. Typical values are at 25°C and nominal supply voltage.
Table 1. Electrical Characteristics
Parameters
Symbol
Min.
Typ.
f
1
–
Max.
Unit
Condition
Frequency Range
Output Frequency Range
110
MHz
Frequency Stability and Aging
Frequency Stability
F_stab
-20
–
+20
ppm
-25
–
+25
ppm
-50
–
+50
ppm
Inclusive of initial tolerance at 25°C, 1st year aging at 25°C, and
variations over operating temperature, rated power supply voltage
and load.
Operating Temperature Range
Operating Temperature Range
T_use
-20
–
+70
°C
Extended Commercial
-40
–
+85
°C
Industrial
Supply Voltage and Current Consumption
Supply Voltage
Current Consumption
OE Disable Current
Standby Current
Rev 1.04
Vdd
Idd
I_OD
I_std
1.62
1.8
1.98
V
2.25
2.5
2.75
V
2.52
2.8
3.08
V
2.7
3.0
3.3
V
2.97
3.3
3.63
V
2.25
–
3.63
V
–
3.8
4.5
mA
No load condition, f = 20 MHz, Vdd = 2.8V to 3.3V
–
3.7
4.2
mA
No load condition, f = 20 MHz, Vdd = 2.5V
–
3.5
4.1
mA
No load condition, f = 20 MHz, Vdd = 1.8V
–
–
4.2
mA
Vdd = 2.5V to 3.3V, OE = GND, Output in high-Z state
–
–
4.0
mA
Vdd = 1.8V, OE = GND, Output in high-Z state
–
2.1
4.3
A
ST
̅ ̅ ̅ = GND, Vdd = 2.8V to 3.3V, Output is weakly pulled down
–
1.1
2.5
A
ST
̅ ̅ ̅ = GND, Vdd = 2.5V, Output is weakly pulled down
–
0.2
1.3
A
ST
̅ ̅ ̅ = GND, Vdd = 1.8V, Output is weakly pulled down
January 30, 2018
Contact SiTime for 1.5V support
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SiT8008B Low Power Programmable Oscillator
Table 1. Electrical Characteristics (continued)
Parameters
Symbol
Min.
Typ.
Max.
Unit
Condition
LVCMOS Output Characteristics
DC
45
–
55
%
All Vdds. See Duty Cycle definition in Figure 3 and Footnote 6
Tr, Tf
–
1
2
ns
Vdd = 2.5V, 2.8V, 3.0V or 3.3V, 20% - 80%
–
1.3
2.5
ns
Vdd =1.8V, 20% - 80%
Vdd = 2.25V - 3.63V, 20% - 80%
Duty Cycle
Rise/Fall Time
–
–
2
ns
Output High Voltage
VOH
90%
–
–
Vdd
Output Low Voltage
VOL
–
–
10%
Vdd
Input High Voltage
VIH
70%
–
–
Vdd
Pin 1, OE or ST
̅ ̅̅
Input Low Voltage
VIL
–
–
30%
Vdd
Pin 1, OE or ST
̅ ̅̅
Input Pull-up Impedance
Z_in
50
87
150
k
Pin 1, OE logic high or logic low, or ST
̅ ̅ ̅ logic high
2
–
–
M
Pin 1, ST
̅ ̅ ̅ logic low
IOH = -4 mA (Vdd = 3.0V or 3.3V)
IOH = -3 mA (Vdd = 2.8V and Vdd = 2.5V)
IOH = -2 mA (Vdd = 1.8V)
IOL = 4 mA (Vdd = 3.0V or 3.3V)
IOL = 3 mA (Vdd = 2.8V and Vdd = 2.5V)
IOL = 2 mA (Vdd = 1.8V)
Input Characteristics
Startup and Resume Timing
Startup Time
T_start
–
–
5
ms
Measured from the time Vdd reaches its rated minimum value
T_oe
–
–
130
ns
f = 110 MHz. For other frequencies, T_oe = 100 ns + 3 * cycles
T_resume
–
–
5
ms
Measured from the time ST
̅ ̅ ̅ pin crosses 50% threshold
Enable/Disable Time
Resume Time
Jitter
RMS Period Jitter
T_jitt
Peak-to-peak Period Jitter
T_pk
RMS Phase Jitter (random)
T_phj
–
1.8
3
ps
f = 75 MHz, Vdd = 2.5V, 2.8V, 3.0V or 3.3V
–
1.8
3
ps
f = 75 MHz, Vdd = 1.8V
–
12
25
ps
f = 75 MHz, Vdd = 2.5V, 2.8V, 3.0V or 3.3V
–
14
30
ps
f = 75 MHz, Vdd = 1.8V
–
0.5
0.9
ps
f = 75 MHz, Integration bandwidth = 900 kHz to 7.5 MHz
–
1.3
2
ps
f = 75 MHz, Integration bandwidth = 12 kHz to 20 MHz
Table 2. Pin Description
Pin
Symbol
Top View
Functionality
[1]
Output Enable
1
OE/ST
̅ ̅ ̅ /NC
Standby
No Connect
H : specified frequency output
L: output is high impedance. Only output driver is disabled.
OE/ST/NC
H[1]: specified frequency output
L: output is low (weak pull down). Device goes to sleep mode. Supply
current reduces to I_std.
Any voltage between 0 and Vdd or Open[1]: Specified frequency
output. Pin 1 has no function.
2
GND
Power
Electrical ground
3
OUT
Output
Oscillator output
4
VDD
Power
Power supply voltage[2]
Figure 1. Pin Assignments
Notes:
1. In OE or ST
̅ ̅ ̅ mode, a pull-up resistor of 10 kΩ or less is recommended if pin 1 is not externally driven. If pin 1 needs to be left floating, use the NC option.
2. A capacitor of value 0.1 µF or higher between Vdd and GND is required.
Rev 1.04
Page 2 of 17
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SiT8008B Low Power Programmable Oscillator
Table 3. Absolute Maximum Limits
Attempted operation outside the absolute maximum ratings may cause permanent damage to the part. Actual performance
of the IC is only guaranteed within the operational specifications, not at absolute maximum ratings.
Parameter
Min.
Max.
Unit
Storage Temperature
-65
150
°C
Vdd
-0.5
4
V
Electrostatic Discharge
–
2000
V
Soldering Temperature
(follow standard Pb free soldering guidelines)
–
260
°C
[3]
–
150
°C
Junction Temperature
Note:
3. Exceeding this temperature for extended period of time may damage the device.
Table 4. Thermal Consideration[4]
Package
JA, 4 Layer Board
JA, 2 Layer Board
JC, Bottom
(°C/W)
(°C/W)
(°C/W)
7050
142
273
30
5032
97
199
24
3225
109
212
27
2520
117
222
26
2016
152
252
36
Note:
4. Refer to JESD51 for JA and JC definitions, and reference layout used to determine the JA and JC values in the above table.
Table 5. Maximum Operating Junction Temperature[5]
Max Operating Temperature (ambient)
Maximum Operating Junction Temperature
70°C
80°C
85°C
95°C
Note:
5. Datasheet specifications are not guaranteed if junction temperature exceeds the maximum operating junction temperature.
Table 6. Environmental Compliance
Parameter
Condition/Test Method
Mechanical Shock
MIL-STD-883F, Method 2002
Mechanical Vibration
MIL-STD-883F, Method 2007
Temperature Cycle
JESD22, Method A104
Solderability
MIL-STD-883F, Method 2003
Moisture Sensitivity Level
MSL1 @ 260°C
Rev 1.04
Page 3 of 17
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SiT8008B Low Power Programmable Oscillator
Test Circuit and Waveform[6]
Vdd
Vout
Test Point
tr
Power
Supply
4
3
1
2
tf
80% Vdd
15pF
(including probe
and fixture
capacitance)
0.1 uF
50%
20% Vdd
High Pulse
(TH)
Low Pulse
(TL)
Vdd
Period
1 kΩ
OE/ST Function
Figure 3. Waveform
Figure 2. Test Circuit
Note:
6. Duty Cycle is computed as Duty Cycle = TH/Period.
Timing Diagrams
90% Vdd
Vdd
Vdd
50% Vdd
Pin 4 Voltage
T_start
[7]
No Glitch
during start up
T_resume
ST Voltage
CLK Output
CLK Output
HZ
HZ
T_start: Time to start from power-off
T_resume: Time to resume from ST
Figure 4. Startup Timing (OE/ ST
̅ ̅ ̅ Mode)
Figure 5. Standby Resume Timing ( ST
̅ ̅ ̅ Mode Only)
Vdd
Vdd
50% Vdd
OE Voltage
OE Voltage
T_oe
50% Vdd
T_oe
CLK Output
CLK Output
HZ
HZ
T_oe: Time to re-enable the clock output
T_oe: Time to put the output in High Z mode
Figure 6. OE Enable Timing (OE Mode Only)
Figure 7. OE Disable Timing (OE Mode Only)
Note:
7. SiT8008 has “no runt” pulses and “no glitch” output during startup or resume.
Rev 1.04
Page 4 of 17
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SiT8008B Low Power Programmable Oscillator
Performance Plots[8]
1.8
2.5
2.8
3.0
3.3
6.0
DUT2
DUT3
DUT4
DUT5
DUT6
DUT7
DUT8
DUT9
DUT10
20
15
Frequency (ppm)
5.5
5.0
Idd (mA)
DUT1
4.5
4.0
3.5
10
5
0
-5
-10
-15
-20
3.0
0
10
20
30
40
50
60
70
80
90
100
-40
110
-30
-20
-10
Frequency (MHz)
Figure 8. Idd vs Frequency
1.8 V
2.5 V
2.8 V
3.0 V
0
10
20
30
40
50
60
70
80
Temperature (°C)
Figure 9. Frequency vs Temperature
3.3 V
1.8 V
2.5 V
2.8 V
3.0 V
3.3 V
55
RMS period jitter (ps)
54
53
ty cyc
(
52
51
50
49
48
47
46
45
0
Frequency (MHz)
20
30
40
50
60
70
80
90
100
110
Frequency (MHz)
Figure 10. RMS Period Jitter vs Frequency
Figure 11. Duty Cycle vs Frequency
Temperature (°C)
Temperature (°C)
Figure 12. 20%-80% Rise Time vs Temperature
Rev 1.04
10
Page 5 of 17
Figure 13. 20%-80% Fall Time vs Temperature
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SiT8008B Low Power Programmable Oscillator
Performance Plots[8]
1.8 V
2.5 V
2.8 V
3.0 V
3.3 V
0.9
IPJ (ps)
0.8
0.7
0.6
0.5
0.4
10
30
50
70
90
10
110
30
50
70
90
110
Frequency (MHz)
Frequency (MHz)
Figure 15. RMS Integrated Phase Jitter Random
(900 kHz to 20 MHz) vs Frequency[9]
Figure 14. RMS Integrated Phase Jitter Random
(12 kHz to 20 MHz) vs Frequency[9]
Notes:
8. All plots are measured with 15 pF load at room temperature, unless otherwise stated.
9. Phase noise plots are measured with Agilent E5052B signal source analyzer. Integration range is up to 5 MHz for carrier frequencies below 40 MHz.
Rev 1.04
Page 6 of 17
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SiT8008B Low Power Programmable Oscillator
Programmable Drive Strength
The SiT8008 includes a programmable drive strength
feature to provide a simple, flexible tool to optimize the
clock rise/fall time for specific applications. Benefits from
the programmable drive strength feature are:
Improves system radiated electromagnetic interference
(EMI) by slowing down the clock rise/fall time.
Improves the downstream clock receiver’s (RX) jitter by
decreasing (speeding up) the clock rise/fall time.
The SiT8008 can support up to 60 pF or higher in
maximum capacitive loads with drive strength settings.
Refer to the Rise/Fall Time Tables (Table 7 to 11) to
determine the proper drive strength for the desired
combination of output load vs. rise/fall time.
SiT8008 Drive Strength Selection
Tables 7 through 11 define the rise/fall time for a given
capacitive load and supply voltage.
1.
Ability to drive large capacitive loads while maintaining
full swing with sharp edge rates.
Select the table that matches the SiT8008 nominal
supply voltage (1.8V, 2.5V, 2.8V, 3.0V, 3.3V).
2.
For more detailed information about rise/fall time control
and drive strength selection, see the SiTime Application
Notes section.
Select the capacitive load column that matches
the application requirement (5 pF to 60 pF)
3.
Under the capacitive load column, select the
desired rise/fall times.
4.
The left-most column represents the part number
code for the corresponding drive strength.
5.
Add the drive strength code to the part number for
ordering purposes.
EMI Reduction by Slowing Rise/Fall Time
Figure 16 shows the harmonic power reduction as the
rise/fall times are increased (slowed down). The rise/fall
times are expressed as a ratio of the clock period. For the
ratio of 0.05, the signal is very close to a square wave. For
the ratio of 0.45, the rise/fall times are very close to neartriangular waveform. These results, for example, show that
the 11th clock harmonic can be reduced by 35 dB if the
rise/fall edge is increased from 5% of the period to 45% of
the period.
trise=0.05
trise=0.1
trise=0.15
trise=0.2
trise=0.25
trise=0.3
trise=0.35
trise=0.4
trise=0.45
10
Harmonic amplitude (dB)
0
-10
-20
Calculating Maximum Frequency
Any given rise/fall time in Table 7 through 11 dictates the
maximum frequency under which the oscillator can operate
with guaranteed full output swing over the entire operating
temperature range. This max frequency can be calculated
as the following:
Max Frequency =
1
5 x Trf_20/80
where Trf_20/80 is the typical value for 20%-80% rise/fall time.
-30
-40
Example 1
-50
-60
Calculate fMAX for the following condition:
-70
-80
1
3
5
7
9
Vdd = 1.8V (Table 7)
Capacitive Load: 30 pF
Desired Tr/f time = 3 ns
(rise/fall time part number code = E)
fMAX = 66.666660
11
Harmonic number
Figure 16. Harmonic EMI reduction as a Function
of Slower Rise/Fall Time
Jitter Reduction with Faster Rise/Fall Time
Power supply noise can be a source of jitter for the downstream chipset. One way to reduce this jitter is to speed up
the rise/fall time of the input clock. Some chipsets may also
require faster rise/fall time in order to reduce their sensitivity
to this type of jitter. Refer to the Rise/Fall Time Tables
(Table 7 to Table 11) to determine the proper drive strength.
High Output Load Capability
Part number for the above example:
SiT8008IE12-18E-66.666660
Drive strength code is inserted here. Default setting is “-”
The rise/fall time of the input clock varies as a function of
the actual capacitive load the clock drives. At any given
drive strength, the rise/fall time becomes slower as the
output load increases. As an example, for a 3.3V SiT8008
device with default drive strength setting, the typical rise/fall
time is 1 ns for 15 pF output load. The typical rise/fall time
slows down to 2.6 ns when the output load increases to 45 pF.
One can choose to speed up the rise/fall time to 1.83 ns by
then increasing the drive strength setting on the SiT8008.
Rev 1.04
Page 7 of 17
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SiT8008B Low Power Programmable Oscillator
Rise/Fall Time (20% to 80%) vs CLOAD Tables
Table 8. Vdd = 2.5V Rise/Fall Times
for Specific CLOAD
Table 7. Vdd = 1.8V Rise/Fall Times
for Specific CLOAD
Rise/Fall Time Typ (ns)
Rise/Fall Time Typ (ns)
Drive Strength \ CLOAD
5 pF
15 pF
30 pF
45 pF
60 pF
Drive Strength \ CLOAD
5 pF
15 pF
30 pF
45 pF
60 pF
L
A
R
B
T
E
U
F or "‐": default
6.16
3.19
2.11
1.65
0.93
0.78
0.70
0.65
11.61
6.35
4.31
3.23
1.91
1.66
1.48
1.30
22.00
11.00
7.65
5.79
3.32
2.94
2.64
2.40
31.27
16.01
10.77
8.18
4.66
4.09
3.68
3.35
39.91
21.52
14.47
11.08
6.48
5.74
5.09
4.56
L
A
R
B
T
E or "‐": default
U
F
4.13
2.11
1.45
1.09
0.62
8.25
4.27
2.81
2.20
1.28
12.82
7.64
5.16
3.88
2.27
21.45
11.20
7.65
5.86
3.51
27.79
14.49
9.88
7.57
4.45
0.54
0.43
0.34
1.00
0.96
0.88
2.01
1.81
1.64
3.10
2.79
2.54
4.01
3.65
3.32
45 pF
18.74
9.86
6.76
5.20
3.07
2.71
2.40
2.16
60 pF
24.30
12.68
8.62
6.64
3.90
3.51
3.13
2.85
Table 9. Vdd = 2.8V Rise/Fall Times
for Specific CLOAD
Table 10. Vdd = 3.0V Rise/Fall Times
for Specific CLOAD
Rise/Fall Time Typ (ns)
Rise/Fall Time Typ (ns)
Drive Strength \ CLOAD
L
A
R
B
T
5 pF
3.77
1.94
1.29
0.97
0.55
15 pF
7.54
3.90
2.57
2.00
1.12
30 pF
12.28
7.03
4.72
3.54
2.08
45 pF
19.57
10.24
7.01
5.43
3.22
60 pF
25.27
13.34
9.06
6.93
4.08
E or "‐": default
U
F
0.44
0.34
0.29
1.00
0.88
0.81
1.83
1.64
1.48
2.82
2.52
2.29
3.67
3.30
2.99
Drive Strength \ CLOAD
L
A
R
B
T or "‐": default
E
U
F
5 pF
3.60
1.84
1.22
0.89
0.51
0.38
0.30
0.27
15 pF
7.21
3.71
2.46
1.92
1.00
0.92
0.83
0.76
30 pF
11.97
6.72
4.54
3.39
1.97
1.72
1.55
1.39
Table 11. Vdd = 3.3V Rise/Fall Times
for Specific CLOAD
Rise/Fall Time Typ (ns)
Drive Strength \ CLOAD
5 pF
15 pF
30 pF
45 pF
60 pF
L
A
R
B
3.39
1.74
1.16
0.81
6.88
3.50
2.33
1.82
11.63
6.38
4.29
3.22
17.56
8.98
6.04
4.52
23.59
12.19
8.34
6.33
T or "‐": default
E
U
F
0.46
0.33
0.28
0.25
1.00
0.87
0.79
0.72
1.86
1.64
1.46
1.31
2.60
2.30
2.05
1.83
3.84
3.35
2.93
2.61
Rev 1.04
Page 8 of 17
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SiT8008B Low Power Programmable Oscillator
Pin 1 Configuration Options (OE, ST
̅ ̅ ̅ , or NC)
Pin 1 of the SiT8008 can be factory-programmed to support
three modes: Output Enable (OE), Standby (ST
̅ ̅ ̅ ) or
No Connect (NC). These modes can also be programmed
with the Time Machine using field programmable devices.
Output Enable (OE) Mode
In the OE mode, applying logic Low to the OE pin only
disables the output driver and puts it in Hi-Z mode. The
core of the device continues to operate normally. Power
consumption is reduced due to the inactivity of the output.
When the OE pin is pulled High, the output is typically
enabled in