SIT8925BE-13-XXE-125.000000 数据手册
SiT8925B
High Frequency, Automotive AEC-Q100 Oscillator
Features
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Applications
AEC-Q100 with extended temperature range (-55°C to
125°C)
Frequencies between 115.2 MHz and 137 MHz accurate to
6 decimal points
100% pin-to-pin drop-in replacement to quartz-based XO
Excellent total frequency stability as low as ±20 ppm
Industry best G-sensitivity of 0.1 PPB/G
Low power consumption of 4.9 mA typical at 1.8 V
Standby mode for longer battery life
LVCMOS/LVTTL 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
RoHS and REACH compliant, Pb-free, Halogen-free and
Antimony-free
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Automotive, extreme temperature and other high-rel
electronics
Infotainment systems, collision detection devices,
and in-vehicle networking
Powertrain control
Electrical Characteristics
Table 1. 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.
Parameter
Symbol
Min.
Typ.
Max.
Unit
Condition
Frequency Range
Output Frequency Range
f
115.20
–
137
MHz
Refer to Tables 13 to 15 for the exact list of supported frequencies
Frequency Stability and Aging
Frequency Stability
F_stab
-20
–
+20
ppm
-25
–
+25
ppm
-30
–
+30
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 (15 pF ±10%).
Operating Temperature Range
Operating Temperature
Range (ambient)
T_use
-40
–
+85
°C
AEC-Q100 Grade 3
-40
–
+105
°C
AEC-Q100 Grade 2
-40
–
+125
°C
AEC-Q100 Grade 1
–
+125
°C
Extended cold, AEC-Q100 Grade1
-55
Supply Voltage and Current Consumption
Supply Voltage
Current Consumption
Standby Current
Vdd
Idd
I_std
1.62
1.8
1.98
V
2.25
–
3.63
V
All voltages between 2.25 V and 3.63 V including 2.5 V, 2.8 V, 3.0 V
and 3.3 V are supported. Contact SiTime for 1.5 V support
–
6
8
mA
No load condition, f = 125 MHz, Vdd = 2.25 V to 3.63 V
–
4.9
6
mA
No load condition, f = 125 MHz, Vdd = 1.62 V to 1.98 V
–
2.6
–
A
Vdd = 2.8 V to 3.3 V, ST = Low, Output is weakly pulled down
–
1.4
–
A
Vdd = 2.5 V, ST = Low, Output is weakly pulled down
–
0.6
–
A
Vdd = 1.8 V, ST = Low, Output is weakly pulled down
LVCMOS Output Characteristics
Duty Cycle
Rise/Fall Time
DC
45
–
55
%
Tr, Tf
–
1.5
3
ns
Vdd = 2.25 V - 3.63 V, 20% - 80%
–
1.2
2.5
ns
Vdd = 1.8 V, 20% - 80%
Output High Voltage
VOH
90%
–
–
Vdd
IOH = -4 mA (Vdd = 3.0 V or 3.3 V)
IOH = -3 mA (Vdd = 2.8 V and Vdd = 2.5 V)
IOH = -2 mA (Vdd = 1.8 V)
Output Low Voltage
VOL
–
–
10%
Vdd
IOL = 4 mA (Vdd = 3.0 V or 3.3 V)
IOL = 3 mA (Vdd = 2.8 V and Vdd = 2.5 V)
IOL = 2 mA (Vdd = 1.8 V)
Rev 1.71
September 14, 2020
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SiT8925B High Frequency, Automotive AEC-Q100 Oscillator
Table 1. Electrical Characteristics (continued)
Parameter
Symbol
Min.
Typ.
Max.
Unit
Condition
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
–
100
–
k
Pin 1, OE logic high or logic low, or ST logic high
2
–
–
MΩ
Pin 1, ST logic low
Input Characteristics
Startup and Resume Timing
Startup Time
Enable/Disable Time
Resume Time
T_start
–
–
5.5
ms
Measured from the time Vdd reaches its rated minimum value
T_oe
–
–
130
ns
f = 115.20 MHz. For other frequencies, T_oe = 100 ns + 3 * cycles
T_resume
–
–
5
ms
Measured from the time ST pin crosses 50% threshold
Jitter
RMS Period Jitter
Peak-to-peak Period Jitter
RMS Phase Jitter (random)
T_jitt
T_pk
T_phj
–
1.6
2.5
ps
f = 125 MHz, 2.25 V to 3.63 V
–
1.8
3
ps
f = 125 MHz, 1.8 V
–
12
20
ps
f = 125 MHz, Vdd = 2.5 V, 2.8 V, 3.0 V or 3.3 V
–
14
30
ps
f = 125 MHz, Vdd = 1.8 V
–
0.7
–
ps
f = 125 MHz, Integration bandwidth = 900 kHz to 7.5 MHz
–
1.5
–
ps
f = 125 MHz, Integration bandwidth = 12 kHz to 20 MHz
Table 2. Pin Description
Pin
Top View
Symbol
Functionality
Output Enable
1
OE/ ST /NC
Standby
No Connect
H[1]: specified frequency output
L: output is high impedance. Only output driver is disabled.
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[2]
3
OUT
Output
Oscillator output
4
VDD
Power
Power supply voltage[2]
OE/ST/NC
1
4
VDD
GND
2
3
OUT
Figure 1. Pin Assignments
Notes:
1. In OE or ST mode, a pull-up resistor of 10 k 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 1.71
Page 2 of 19
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SiT8925B High Frequency, Automotive AEC-Q100 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.
Min.
Max.
Unit
Storage Temperature
Parameter
-65
150
°C
Vdd
-0.5
4
V
Electrostatic Discharge
–
2000
V
Soldering Temperature (follow standard Pb free soldering guidelines)
–
260
°C
Junction Temperature[3]
–
150
°C
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:
3. Exceeding this temperature for extended period of time may damage the device.
Table 4. Thermal Consideration[4]
Package
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
85°C
93°C
105°C
113°C
125°C
133°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 1.71
Page 3 of 19
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SiT8925B High Frequency, Automotive AEC-Q100 Oscillator
Test Circuit and Waveform
Vdd
Vout
0.1 µF
tr
3
4
Power
Supply
Test
Point
1
tf
80% Vdd
15 pF
(including probe
and fixture
capacitance)
2
50%
20% Vdd
High Pulse
(TH)
Low Pulse
(TL)
Period
Vdd
1 k
OE/ST/NC Function
Figure 2. Test Circuit[6]
Figure 3. Waveform[6]
Note:
6. Duty Cycle is computed as Duty Cycle = TH/Period.
Timing Diagrams
Vdd
Vdd
90% Vdd
50% Vdd
T_start
Pin 4 Voltage
No Glitch
during start up
ST Voltage
CLK Output
T_resume
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)[7]
Figure 5. Standby Resume Timing ( ST Mode Only)
Vdd
Vdd
50% Vdd
OE Voltage
50% Vdd
T_oe
OE Voltage
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. SiT8925 has “no runt” pulses and “no glitch” output during startup or resume.
Rev 1.71
Page 4 of 19
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SiT8925B High Frequency, Automotive AEC-Q100 Oscillator
Performance Plots[8]
1.8
2.5
2.8
3.0
3.3
6.5
6.3
DUT1
DUT2
DUT3
DUT4
DUT5
DUT6
DUT7
DUT8
DUT9
DUT10
DUT11
DUT12
DUT13
DUT14
DUT15
DUT16
DUT17
DUT18
DUT19
DUT20
25
6.1
20
Frequency (ppm)
Idd (mA)
5.9
5.7
5.5
5.3
5.1
15
10
5
0
-5
-10
4.9
-15
4.7
-20
-25
4.5
115
117
119
121
123
125
127
129
131
133
135
-55
137
-35
-15
Frequency (MHz)
2.5 V
2.8 V
25
45
65
85
105
125
Figure 9. Frequency vs Temperature
Figure 8. Idd vs Frequency
1.8 V
5
Temperature (°C)
3.0 V
1.8 V
3.3 V
2.5 V
2.8 V
3.0 V
3.3 V
55
4.0
54
53
3.0
Duty cycle (%)
RMS period jitter (ps)
3.5
2.5
2.0
1.5
1.0
52
51
50
49
48
47
46
0.5
45
0.0
115
117
119
121
123
125
127
129
131
133
135
115
137
117
119
121
123
Frequency (MHz)
2.8 V
3.0 V
1.8 V
3.3 V
2.5
2.5
2.0
2.0
Fall time (ns)
Rise time (ns)
2.5 V
1.5
129
131
133
135
137
1.0
2.5 V
2.8 V
3.0 V
3.3 V
1.5
1.0
0.5
0.5
0.0
0.0
-40
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
100 110 120
-40
Temperature (°C)
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
100 110 120
Temperature (°C)
Figure 12. 20%-80% Rise Time vs Temperature
Rev 1.71
127
Figure 11. Duty Cycle vs Frequency
Figure 10. RMS Period Jitter vs Frequency
1.8 V
125
Frequency (MHz)
Figure 13. 20%-80% Fall Time vs Temperature
Page 5 of 19
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SiT8925B High Frequency, Automotive AEC-Q100 Oscillator
Performance Plots[8]
1.8 V
2.5 V
2.8 V
3.0 V
1.8 V
3.3 V
2.0
2.5 V
2.8 V
3.0 V
3.3 V
1.0
0.9
1.8
IPJ (ps)
IPJ (ps)
0.8
1.6
1.4
0.7
0.6
1.2
0.5
1.0
0.4
115
117
119
121
123
125
127
129
131
133
135
137
115
Frequency (MHz)
117
119
121
123
125
127
129
131
133
135
137
Frequency (MHz)
Figure 14. RMS Integrated Phase Jitter Random
(12 kHz to 20 MHz) vs Frequency[9]
Figure 15. RMS Integrated Phase Jitter Random
(900 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.
Rev 1.71
Page 6 of 19
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SiT8925B High Frequency, Automotive AEC-Q100 Oscillator
Programmable Drive Strength
The SiT8925 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.
◼ Ability to drive large capacitive loads while maintaining
full swing with sharp edge rates.
For more detailed information about rise/fall time control
and drive strength selection, see the SiTime Application
Notes section.
The SiT8925 can support up to 30 pF in maximum
capacitive loads with up to 3 additional drive strength
settings. Refer to the Rise/Tall Time Tables (Table 7 to 11)
to determine the proper drive strength for the desired
combination of output load vs. rise/fall time.
SiT8925 Drive Strength Selection
Tables 7 through 11 define the rise/fall time for a given capacitive load and supply voltage.
1. Select the table that matches the SiT8925 nominal
supply voltage (1.8 V, 2.5 V, 2.8 V, 3.0 V, 3.3 V)
2. Select the capacitive load column that matches the
application requirement (5 pF to 30 pF)
3. Under the capacitive load column, select the desired
rise/fall times.
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
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.
Calculating Maximum Frequency
Based on the rise and fall time data given in Tables 7
through 11, the maximum frequency the oscillator can operate with guaranteed full swing of the output voltage over
temperature as follows:
Max Frequency =
1
5 x Trf_20/80
-30
-40
where Trf_20/80 is the typical value for 20%-80% rise/fall
time.
-50
-60
-70
-80
Example 1
1
3
5
7
9
11
Harmonic number
Calculate fMAX for the following condition:
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.
◼
Vdd = 3.3 V (Table 11)
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Capacitive Load: 30 pF
◼
Desired Tr/f time = 1.46 ns
(rise/fall time part number code = U)
Part number for the above example:
SiT8925BAE12-18E-137.000000
Drive strength code is inserted here. Default setting is “-”
High Output Load Capability
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 3.3 V SiT8925
device with default drive strength setting, the typical
rise/fall time is 0.46 ns for 5 pF output load. The typical
rise/fall time slows down to 1 ns when the output load
increases to 15 pF. One can choose to speed up the rise/fall
time to 0.72 ns by then increasing the driven strength setting
on the SiT8925 to “F”.
Rev 1.71
Page 7 of 19
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SiT8925B High Frequency, Automotive AEC-Q100 Oscillator
Rise/Fall Time (20% to 80%) vs CLOAD Tables[10]
Table 7. Vdd = 1.8 V Rise/Fall Times
for Specific CLOAD
Table 8. Vdd = 2.5 V Rise/Fall Times
for Specific CLOAD
Rise/Fall Time Typ (ns)
Drive Strength\ CLOAD
5 pF
15 pF
T
0.93
n/a
Rise/Fall Time Typ (ns)
Drive Strength \ CLOAD
5 pF
R
1.45
15 pF
n/a
E
0.78
n/a
B
1.09
n/a
U
0.70
1.48
T or "-": default
0.62
1.28
F or "-": default
0.65
1.30
Table 9. Vdd = 2.8 V Rise/Fall Times
for Specific CLOAD
1.00
0.43
0.96
F
0.34
0.88
n/a
30 pF
n/a
B
0.89
n/a
T or "-": default
0.51
1.00
n/a
n/a
n/a
E
0.38
0.92
n/a
n/a
U
0.30
0.83
n/a
1.48
F
0.27
0.76
1.39
0.97
n/a
T or "-": default
0.55
1.12
n/a
n/a
E
0.44
1.00
U
0.34
0.88
0.81
Rise/Fall Time Typ (ns)
Drive Strength \ CLOAD
5 pF
15 pF
n/a
R
1.22
30 pF
B
0.29
0.54
Table 10. Vdd = 3.0 V Rise/Fall Times
for Specific CLOAD
Rise/Fall Time Typ (ns)
Drive Strength \ CLOAD
5 pF
15 pF
n/a
R
1.29
F
E
U
Table 11. Vdd = 3.3 V Rise/Fall Times
for Specific CLOAD
Rise/Fall Time Typ (ns)
Drive Strength \ CLOAD
5 pF
15 pF
n/a
R
1.16
30 pF
n/a
B
0.81
n/a
n/a
T or "-": default
0.46
1.00
n/a
E
0.33
0.87
n/a
U
0.28
0.79
1.46
F
0.25
0.72
1.31
Note:
10. “n/a” indicates that the resulting rise/fall time from the respective combination of the drive strength and output load does not provide rail-to-rail swing and is not
available.
Rev 1.71
Page 8 of 19
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SiT8925B High Frequency, Automotive AEC-Q100 Oscillator
In addition, the SiT8925 supports “no runt” pulses and “no
glitch” output during startup or when the device output
driver is enabled as shown in the waveform captures in
Figure 17 and Figure 18.
Pin 1 Configuration Options
(OE, ST , or NC)
Pin 1 of the SiT8925 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 II using Field Programmable Oscillators.
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