SIT8945BIU81-28EA115.200000T datasheet, PDF

SiT8945B

115.2 – 137 MHz, -55 to 125°C, Endura™ Series Oscillator

Features

◼

Applications

◼

Best acceleration sensitivity of 0.1 ppb/g

Any 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

Low power consumption of 3.8 mA typical at 1.8V

LVCMOS/LVTTL compatible output

AEC-Q100 qualified

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

Contact SiTime

for up-screening and LAT programs

Avionics systems

Field communication systems

Telemetry applications

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

Output Frequency Range

Frequency Stability

Symbol

f

F_stab

Min.

115.20

-20

-25

-30

-50

Operating Temperature

Range (ambient)

T_use

-40

-55

Acceleration (g) sensitivity,

Gamma Vector

Supply Voltage

Current Consumption

F_g

–

Typ.

–

Max.

137

+20

+25

+30

+50

+85

+105

+125

0.1

Unit

MHz

ppm

°C

ppb/g

AEC-Q100 Grade 3

AEC-Q100 Grade 2

AEC-Q100 Grade 1

Extended cold, AEC-Q100 Grade1

Low sensitivity grade; total gamma over 3 axes; 15 Hz to 2 kHz;

MIL-PRF-55310, computed per section 4.8.18.3.1

All voltages between 2.25V and 3.63V including 2.5V, 2.8V, 3.0V and 3.3V

are supported.

Contact SiTime

for 1.5V support

No load condition, f = 125 MHz, Vdd = 2.25V to 3.63V

No load condition, f = 125 MHz, Vdd = 1.62V to 1.98V

Condition

Refer to Tables 13 to 15 for the exact

list of supported frequencies

Inclusive of Initial tolerance at 25°C, 1

st

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

Operating Temperature Range

Rugged Characteristics

Supply Voltage and Current Consumption

Vdd

Idd

1.62

2.25

–

Duty Cycle

Rise/Fall Time

Output High Voltage

DC

Tr, Tf

VOH

45

–

90%

1.8

–

6

4.9

–

1.5

–

1.98

3.63

8

6

55

3

2.5

–

V

mA

%

ns

Vdd

Vdd = 2.25V - 3.63V, 20% - 80%

Vdd = 1.8V, 20% - 80%

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)

Pin 1, OE

Pin 1, OE logic high or logic low

LVCMOS Output Characteristics

Output Low Voltage

VOL

–

10%

Vdd

Input Characteristics

Input High Voltage

Input Low Voltage

Input Pull-up Impedance

VIH

VIL

Z_in

70%

–

100

–

30%

–

Vdd

k

Rev 1.00

July 24, 2020

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SiT8945B

115.2 – 137 MHz, -55 to 125°C, Endura

™

Series Oscillator

Table 1. Electrical Characteristics

(continued)

Parameter

Startup Time

Enable/Disable Time

Standby Current

Symbol

T_start

T_oe

I_std

Min.

–

RMS Period Jitter

Peak-to-peak Period Jitter

RMS Phase Jitter (random)

T_jitt

T_pk

T_phj

–

Typ.

–

2.6

1.4

0.6

1.6

1.8

12

14

0.7

1.5

Max.

5

130

–

2.5

3

20

30

–

Unit

ms

ns

A

Jitter

ps

f = 125 MHz, 2.25V to 3.63V

f = 125 MHz, 1.8V

PRELIMINARY

Condition

Measured from the time Vdd reaches its rated minimum value

f = 115.20 MHz. For other frequencies, T_oe = 100 ns + 3 * cycles

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

Startup and Resume Timing

f = 125 MHz, Vdd = 2.5V, 2.8V, 3.0V or 3.3V

f = 125 MHz, Vdd = 1.8V

f = 125 MHz, Integration bandwidth = 900 kHz to 7.5 MHz

f = 125 MHz, Integration bandwidth = 12 kHz to 20 MHz

Table 2. Pin Description

Symbol

Output Enable

1

OE/NC

No Connect

2

3

4

GND

OUT

VDD

Power

Output

Power

Functionality

H

[1]

: specified frequency output

L: output is high impedance. Only output driver is disabled.

Any voltage between 0 and Vdd or Open

[1]

: Specified frequency

output. Pin 1 has no function.

Electrical ground

[2]

Oscillator output

Power supply voltage

[2]

GND

2

Top View

OE/NC

1

4

VDD

3

OUT

Figure 1. Pin Assignments

Notes:

1. In OE mode, a pull-up resistor of 10k 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 1.00

Page 2 of 15

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SiT8945B

115.2 – 137 MHz, -55 to 125°C, Endura

™

Series Oscillator

PRELIMINARY

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

Storage Temperature

Vdd

Electrostatic Discharge

Soldering Temperature (follow standard Pb free soldering guidelines)

Junction Temperature

[3]

Note:

3. Exceeding this temperature for extended period of time may damage the device.

Min.

-65

-0.5

–

Max.

150

4

2000

260

150

Unit

°C

V

°C

Table 4. Thermal Consideration

[4]

Package

7050

5032

3225

2520

2016



JA, 4 Layer Board

(°C/W)

142

97

109

117

152



JA, 2 Layer Board

(°C/W)

273

199

212

222

252



JC, Bottom

(°C/W)

30

24

27

26

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)

85°C

105°C

125°C

Maximum Operating Junction Temperature

93°C

113°C

133°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 1.00

Page 3 of 15

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SiT8945B

115.2 – 137 MHz, -55 to 125°C, Endura

™

Series Oscillator

Test Circuit and Waveform

Vdd

Vout

Test

Point

PRELIMINARY

tr

80% Vdd

tf

4

Power

Supply

0.1µF

3

15pF

(including probe

and fixture

capacitance)

50%

20% Vdd

High Pulse

(TH)

Period

Low Pulse

(TL)

1

2

Vdd

OE/NC Function

1k



Figure 2. Test Circuit

[6]

Note:

6. Duty Cycle is computed as Duty Cycle = TH/Period.

Figure 3. Waveform

Timing Diagrams

90% Vdd

Vdd

50% Vdd

T_oe

Vdd

Pin 4 Voltage

T_start

No Glitch

during start up

OE Voltage

CLK Output

HZ

CLK Output

HZ

T_start: Time to start from power-off

T_oe: Time to re-enable the clock output

Figure 4. Startup Timing (OE Mode)

[7]

Figure 5. OE Enable Timing (OE Mode Only)

Vdd

OE Voltage

50% Vdd

T_oe

CLK Output

HZ

T_oe: Time to put the output in High Z mode

Figure 6. OE Disable Timing (OE Mode Only)

Note:

7. SiT8945 has “no runt” pulses and “no glitch” output during startup or resume.

Rev 1.00

Page 4 of 15

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SiT8945B

115.2 – 137 MHz, -55 to 125°C, Endura

™

Series Oscillator

Performance Plots

[8]

1.8

6.5

6.3

6.1

5.9

2.5

2.8

3.0

3.3

PRELIMINARY

DUT1

DUT8

DUT15

25

DUT2

DUT9

DUT16

DUT3

DUT10

DUT17

DUT4

DUT11

DUT18

DUT5

DUT12

DUT19

DUT6

DUT13

DUT20

DUT7

DUT14

Frequency (ppm)

115

117

119

121

123

125

127

129

131

133

135

137

20

15

10

Idd (mA)

5.7

5.5

5.3

5.1

4.9

4.7

4.5

5

0

-5

-10

-15

-20

-25

-55

-35

-15

5

25

45

65

85

105

125

Frequency (MHz)

Temperature (°C)

Figure 7. Idd vs Frequency

Figure 8. Frequency vs Temperature

1.8 V

4.0

3.5

2.5 V

2.8 V

3.0 V

3.3 V

55

54

1.8 V

2.5 V

2.8 V

3.0 V

3.3 V

RMS period jitter (ps)

53

2.5

2.0

1.5

1.0

0.5

0.0

115

117

119

121

123

125

127

129

131

133

135

137

Duty cycle (%)

3.0

52

51

50

49

48

47

46

45

115

117

119

121

123

125

127

129

131

133

135

137

Frequency (MHz)

Figure 9. RMS Period Jitter vs Frequency

Figure 10. Duty Cycle vs Frequency

1.8 V

2.5

2.5 V

2.8 V

3.0 V

3.3 V

1.8 V

2.5

2.5 V

2.8 V

3.0 V

3.3 V

2.0

Rise time (ns)

1.5

Fall time (ns)

-40

-30

-20

-10

0

10

20

30

40

50

60

70

80

90

100 110 120

1.5

1.0

0.5

0.0

-40

-30

-20

-10

0

10

20

30

40

50

60

70

80

90

100 110 120

Temperature (°C)

Figure 11. 20%-80% Rise Time vs Temperature

Figure 12. 20%-80% Fall Time vs Temperature

Rev 1.00

Page 5 of 15

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Parameter Name	Attribute value
Is it Rohs certified?	conform to
Objectid	145139003518
package instruction	DILCC4,.2,200
Reach Compliance Code	unknown
Other features	ENABLE/DISABLE FUNCTION; ALSO COMPATIBLE WITH LVTTL O/P
maximum descent time	2.5 ns
Frequency Adjustment - Mechanical	NO
frequency stability	20%
JESD-609 code	e4
Installation features	SURFACE MOUNT
Number of terminals	4
Nominal operating frequency	115.2 MHz
Maximum operating temperature	85 °C
Minimum operating temperature	-40 °C
Oscillator type	LVCMOS
Output load	15 pF
Maximum output low current	3 mA
Encapsulate equivalent code	DILCC4,.2,200
physical size	7.0mm x 5.0mm x 1.05mm
longest rise time	2.5 ns
Filter level	AEC-Q100
Maximum supply voltage	3.08 V
Minimum supply voltage	2.52 V
Nominal supply voltage	2.8 V
surface mount	YES
maximum symmetry	55/45 %
Terminal surface	Nickel/Palladium/Gold (Ni/Pd/Au)

SIT8945BIU81-28EA115.200000T

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