SiT2018B
High Temp, Single-Chip, One-Output Clock Generator
The Smart Timing Choice
The Smart Timing Choice
Features
Applications
Frequencies between 1 MHz and 110 MHz accurate to 6 decimal
places
Operating temperature from -40°C to 125°C. For -55°C option, refer
to
SiT2020
and
SiT2021
Supply voltage of 1.8V or 2.5V to 3.3V
Excellent total frequency stability as low as ±20 ppm
Low power consumption of 3.5 mA typical at 1.8V
LVCMOS/LVTTL compatible output
5-pin SOT23-5 package: 2.9mm x 2.8mm
RoHS and REACH compliant, Pb-free, Halogen-free and
Antimony-free
For AEC-Q100 clock generators, refer to
SiT2024
and
SiT2025
Industrial, medical, automotive, avionics and other high temper-
ature applications
Industrial sensors, PLC, motor servo, outdoor networking
equipment, medical video cam, asset tracking systems, etc.
Electrical Specifications
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.
Parameters
Output Frequency Range
Symbol
f
Min.
1
Typ.
–
Max.
110
Unit
MHz
Condition
Refer to
Table 14
for the exact list of supported frequencies
list of supported frequencies
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%).
Frequency Range
Frequency Stability and Aging
Frequency Stability
F_stab
-20
-25
-30
-50
Operating Temperature Range
(ambient)
T_use
-40
-40
Vdd
1.62
2.25
2.52
2.7
2.97
2.25
Current Consumption
Idd
–
–
–
OE Disable Current
Standby Current
I_od
I_std
–
–
–
–
–
Duty Cycle
Rise/Fall Time
DC
Tr, Tf
45
–
–
–
Output High Voltage
VOH
90%
–
–
–
–
–
–
1.8
2.5
2.8
3.0
3.3
–
3.8
3.6
3.5
–
–
2.6
1.4
0.6
–
1.0
1.3
1.0
–
+20
+25
+30
+50
+105
+125
1.98
2.75
3.08
3.3
3.63
3.63
4.7
4.5
4.5
4.5
4.3
8.5
5.5
4.0
55
2.0
2.5
3
–
ppm
ppm
ppm
ppm
°C
°C
V
V
V
V
V
V
mA
mA
mA
mA
mA
A
A
A
%
ns
ns
ns
Vdd
No load condition, f = 20 MHz, Vdd = 2.8V, 3.0V or 3.3V
No load condition, f = 20 MHz, Vdd = 2.5V
No load condition, f = 20 MHz, Vdd = 1.8V
Vdd = 2.5V to 3.3V, OE = Low, Output in high Z state.
Vdd = 1.8V, OE = Low, Output in high Z state.
Vdd = 2.8V to 3.3V, ST = Low, Output is weakly pulled down
Vdd = 2.5V, ST = Low, Output is weakly pulled down
Vdd = 1.8V, ST = Low, Output is weakly pulled down
All Vdds
Vdd = 2.5V, 2.8V, 3.0V or 3.3V, 20% - 80%
Vdd =1.8V, 20% - 80%
Vdd = 2.25V - 3.63V, 20% - 80%
IOH = -4 mA (Vdd = 3.0V or 3.3V)
IOH = -3 mA (Vdd = 2.8V or 2.5V)
IOH = -2 mA (Vdd = 1.8V)
IOL = 4 mA (Vdd = 3.0V or 3.3V)
IOL = 3 mA (Vdd = 2.8V or 2.5V)
IOL = 2 mA (Vdd = 1.8V)
Extended Industrial
Automotive
Operating Temperature Range
Supply Voltage and Current Consumption
Supply Voltage
LVCMOS Output Characteristics
Output Low Voltage
VOL
–
–
10%
Vdd
SiTime Corporation
Rev. 1.0
990 Almanor Avenue, Sunnyvale, CA 94085
(408) 328-4400
www.sitime.com
Revised May 14, 2015
SiT2018B
High Temp, Single-Chip, One-Output Clock Generator
The Smart Timing Choice
The Smart Timing Choice
Table 1. Electrical Characteristics (continued)
Parameters
Input High Voltage
Input Low Voltage
Input Pull-up Impedence
Symbol
VIH
VIL
Z_in
Min.
70%
–
50
2
Startup Time
Enable/Disable Time
Resume Time
RMS Period Jitter
Peak-to-peak Period Jitter
RMS Phase Jitter (random)
T_start
T_oe
T_resume
T_jitt
T_pk
T_phj
–
–
–
–
–
–
–
–
–
Typ.
–
–
87
–
–
–
–
1.6
1.9
12
14
0.5
1.3
Max.
–
30%
150
–
5
130
5
Jitter
2.5
3
20
25
0.8
2
ps
ps
ps
ps
ps
ps
f = 75 MHz, Vdd = 2.5V, 2.8V, 3.0V or 3.3V
f = 75 MHz, Vdd = 1.8V
f = 75 MHz, Vdd = 2.5V, 2.8V, 3.0V or 3.3V
f = 75 MHz, Vdd = 1.8V
f = 75 MHz, Integration bandwidth = 900 kHz to 7.5 MHz
f = 75 MHz, Integration bandwidth = 12 kHz to 20 MHz
Unit
Vdd
Vdd
k
M
ms
ns
ms
Pin 3, OE or ST
Pin 3, OE or ST
Pin 3, OE logic high or logic low, or ST logic high
Pin 3, ST logic low
Measured from the time Vdd reaches its rated minimum value
f = 110 MHz. For other frequencies, T_oe = 100 ns + 3 * clock
periods
Measured from the time ST pin crosses 50% threshold
Condition
Input Characteristics
Startup and Resume Timing
Table 2. Pin Description
Pin
1
2
Symbol
GND
NC
Power
No Connect
Output
Enable
3
OE/ ST/NC
Standby
No Connect
4
5
VDD
OUT
Power
Output
Electrical ground
No connect
specified frequency output
L: output is high impedance. Only output driver is disabled.
H or Open
[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 3 has no function.
Power supply voltage
[2]
Oscillator output
4
Top View
Functionality
OE/ST/NC NC
3
2
GND
1
H
[1]
:
5
VDD
OUT
Notes:
1. In OE or ST mode, a pull-up resistor of 10 kΩ or less is recommended if pin 3 is not externally driven.
If pin 3 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.
Figure 1. Pin Assignments
Rev. 1.0
Page 2 of 12
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SiT2018B
High Temp, Single-Chip, One-Output Clock Generator
The Smart Timing Choice
The Smart Timing Choice
N
Table 3. Absolute Maximum Limits
Attempted operation outside the absolute maximum ratings of the part may cause permanent damage to the part. Actual perfor-
mance of the IC is only guaranteed within the operational specifications, not at absolute maximum ratings.
Parameter
Storage Temperature
Vdd
Electrostatic Discharge
Soldering Temperature (follow standard Pb free soldering guidelines)
Junction Temperature
[3]
Min.
-65
-0.5
–
–
–
Max.
150
4
2000
260
150
Unit
°C
V
V
°C
°C
Note:
3. Exceeding this temperature for extended period of time may damage the device.
Table 4. Thermal Consideration
[4]
Package
SOT23-5
JA
, 4 Layer Board
(°C/W)
421
JC
, Bottom
(°C/W)
175
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)
105°C
125°C
Maximum Operating Junction Temperature
115°C
135°C
Note:
5. Datasheet specifications are not guaranteed if junction temperature exceeds the maximum operating junction temperature.
Table 6. Environmental Compliance
Parameter
Mechanical Shock
Mechanical Vibration
Temperature Cycle
Solderability
Moisture Sensitivity Level
Condition/Test Method
MIL-STD-883F, Method 2002
MIL-STD-883F, Method 2007
JESD22, Method A104
MIL-STD-883F, Method 2003
MSL1 @ 260°C
Rev. 1.0
Page 3 of 12
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SiT2018B
High Temp, Single-Chip, One-Output Clock Generator
The Smart Timing Choice
The Smart Timing Choice
Test Circuit and Waveform
[6]
Test
Point
Vout
Vdd
Tr
5
4
0.1µF
Power
Supply
Tf
15 pF
(including probe
and fixture
capacitance)
1
2
3
80% Vdd
50%
20% Vdd
High Pulse
(TH)
Low Pulse
(TL)
Period
Vdd
1k
OE/ST Function
Figure 2. Test Circuit
Note:
6. Duty Cycle is computed as Duty Cycle = TH/Period.
Figure 3. Output Waveform
Timing Diagrams
Vdd
90% Vdd
Vdd
50% Vdd
[7]
Pin 4 Voltage
T_start
No Glitch
during start up
ST Voltage
T_resume
CLK Output
HZ
CLK Output
HZ
T_start: Time to start from power-off
T_resume: Time to resume from ST
Figure 4. Startup Timing (OE/ST Mode)
u
Vdd
50% Vdd
OE Voltage
T_oe
Figure 5. Standby Resume Timing (ST Mode Only)
Vdd
OE Voltage
50% Vdd
T_oe
CLK Output
HZ
CLK Output
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)
Note:
7. SiT2018 has “no runt” pulses and “no glitch” output during startup or resume.
Figure 7. OE Disable Timing (OE Mode Only)
Rev. 1.0
Page 4 of 12
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SiT2018B
High Temp, Single-Chip, One-Output Clock Generator
The Smart Timing Choice
The Smart Timing Choice
Performance Plots
[8]
1.8 V
6.0
2.5 V
2.8 V
3V
3.3 V
DUT1
DUT8
DUT15
25
20
DUT2
DUT9
DUT16
DUT3
DUT10
DUT17
DUT4
DUT11
DUT18
DUT5
DUT12
DUT19
DUT6
DUT13
DUT20
DUT7
DUT14
5.5
Frequency (ppm)
0
20
40
60
80
100
5.0
15
10
5
0
-5
-10
-15
-20
Idd (mA)
4.5
4.0
3.5
3.0
-25
‐55
‐35
‐15
5
25
45
65
85
105
125
Frequency (MHz)
Temperature (°C)
Figure 8. Idd vs Frequency
Figure 9. Frequency vs Temperature
1.8 V
4.0
3.5
2.5 V
2.8 V
3.0 V
3.3 V
55
54
53
52
1.8 V
2.5 V
2.8 V
3.0 V
3.3 V
RMS period jitter (ps)
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0
20
40
60
80
100
Duty cycle (%)
51
50
49
48
47
46
45
0
20
40
60
80
100
Frequency (MHz)
Frequency (MHz)
Figure 10. RMS Period Jitter vs Frequency
Figure 11. Duty Cycle vs Frequency
1.8 V
2.5
2.5 V
2.8 V
3.0 V
3.3 V
2.5
1.8 V
2.5 V
2.8 V
3.0 V
3.3 V
2.0
2.0
Rise time (ns)
Fall time (ns)
1.5
1.5
1.0
1.0
0.5
0.5
0.0
-40
-20
0
20
40
60
80
100
120
0.0
-40
-20
0
20
40
60
80
100
120
Temperature (°C)
Temperature (°C)
Figure 12. 20%-80% Rise Time vs Temperature
Figure 13. 20%-80% Fall Time vs Temperature
Rev. 1.0
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