The Smart Timing Choice
The Smart Timing Choice
SiTime Corporation 990 Almanor Avenue Sunnyvale, CA 94085 (408) 328-4400 www.sitime.com
Rev. 1.2 Revised July 24, 2014
SiT3907
High Precision Digitally Controlled Oscillator (DCXO)
Notes:
1. Absolute Pull Range (APR) is defined as the guaranteed pull range over temperature and voltage.
2. APR = pull range (PR) - frequency stability (F_stab) - Aging (F_aging)
Features Applications
Factory programmable between 1 MHz and 220 MHz Ideal for clock synchronization, instrumentation, low
bandwidth PLL, jitter cleaner, clock recovery, audio,
video, and FPGA
Digitally controlled pull range: ±25, ±50, ±100, ±200, ±400, ±800,
±1600 PPM
Eliminate the need for an external DAC
Superior pull range linearity of <= 0.01%
LVCMOS/LVTTL compatible output
Three industry-standard packages: 3.2 mm x2.5 mm (4-pin), 5.0 mm
x 3.2 mm (6-pin), 7.0 mm x 5.0 mm (6-pin)
Programmable drive strength to reduce EMI
Outstanding silicon reliability of 2 FIT
Electrical Characteristics
Parameters Symbol Min. Typ. Max. Unit Condition
Output Frequency Range f 1 – 220 MHz
Frequency Stability F_stab
-10 – +10 PPM Inclusive of initial tolerance, operating temperature, rated
power, supply voltage and load change-25 – +25 PPM
-50 – +50 PPM
Aging F_aging -5 – +5 PPM 10 years
Operating Temperature Range T_use -20 – +70 °C Extended Commercial
-40 – +85 °C Industrial
Supply Voltage Vdd
1.71 1.8 1.89 V
2.25 2.5 2.75 V
2.52 2.8 3.08 V
2.97 3.3 3.63 V
Pull Range PR ±25, ±50, ±100, ±200
±400, ±800, ±1600 PPM See the last page for Absolute Pull Range, APR table
Linearity Lin – – 0.01 %
Frequency Change Polarity – Positive Slope –
Frequency Update Rate F_update – – 25 kU / s Frequency control mode 1, see Table 1
– – 12.5 kU / s Frequency control mode 2, see Table 2
Current Consumption Idd – 32 34 mA No load condition, f = 100 MHz, Vdd = 2.5V, 2.8V or 3.3V
– 31 34 mA No load condition, f = 100 MHz, Vdd = 1.8 V
Duty Cycle DC 45 – 55 % Vdd = 1.8V, 2.5V, 2.8V or 3.3V
Rise/Fall Time Tr, Tf – 1.2 2 ns Vdd =1.8V, 2.5V, 2.8V or 3.3V, 10% - 90% Vdd level
Output High Voltage VOH 90 – – %Vdd IOH = -6mA, Vdd = 3.3V, 2.8V, 2.5V
IOL = -3mA, Vdd = 1.8V
Output Low Voltage VOL – – 10 %Vdd IOH = -6mA, Vdd = 3.3V, 2.8V, 2.5V
IOL = -3mA, Vdd = 1.8V
Output Load Ld – – 15 pF
Start-up Time T_start – 6 10 ms
Input Low Voltage VIL – – 0.2xVdd V See Figure 5
Input Middle Voltage VIM 0.4xVdd – 0.6xVdd V See Figure 5
Input High Voltage VIH 0.8xVdd – – V See Figure 5
Input High or Low Logic Pulse T_logic 500 – – ns See Figure 5
Input Middle Pulse Width T_middle 500 – – ns See Figure 5
Input Impedance Zin 100 – – kΩ
Input Capacitance Cin – 5 – pF 20% to 80%
RMS period Jitter T_jitt – 1.5 2 ps f = 20 MHz, all Vdds
– 2 3 ps f = 20 MHz, all Vdds
RMS Phase Jitter (random) T_phj – 0.6 1 ps f = 20 MHz, Integration bandwidth = 12 kHz to 20 MHz,
all Vdds. No activity on DP pin.
– 0.65 1 ps With full activity on DP pin.
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SiT3907
High Precision Digitally Controlled Oscillator (DCXO)
Rev. 1.2 Page 2 of 10 www.sitime.com
Pin Description (4-pin device)
Pin Map Functionality
1 Digital Programming Pin (DPpin) See “Frequency Control Protocol Description” section
2 GND Electrical ground[3]
3 CLK Oscillator output
4 VDD VDD power supply[3]
Pin Description (6-pin device)
Pin Map Functionality
1 Digital Programming Pin (DPpin) See “Frequency Control Protocol Description” section
2NC No connect
3 GND Electrical ground[3]
4 CLK Oscillator output
5 NC No connect
6 VDD VDD power supply[3]
Note:
3. A capacitor value of 0.1 µF between VDD and GND is required.
Absolute Maximum
Attempted operation outside the absolute maximum ratings of the part 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 –2000V
Soldering Temperature (follow standard Pb free soldering guidelines) – 260 °C
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
1 4
DP VDD
32
GND CLK
Top View
43
1 6
DP
GND
VDD
CLK
52
NC NC
Top View
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SiT3907
High Precision Digitally Controlled Oscillator (DCXO)
Rev. 1.2 Page 3 of 10 www.sitime.com
Description
SiT3907 device is a digitally controlled programmable oscillator (DCXO), which allows pulling the frequency around a nominal
value dynamically. User can communicate with the device through a 1-pin tri-level serial interface. This device has two DCXO
registers, which control the amount of frequency pull. Once the registers are set, the device sets its output frequency to a new
value dynamically. The pull range is programmable to a maximum of ±1600 PPM. The resolution varies between1 part-per-billion
(ppb) and 50 ppb depending on total pull range selected. Writing into the DCXO registers does not cause any interruptions of
output oscillations; the frequency will switch from one value to the new one smoothly.
The device allows two modes of operation. In mode 1, user can set one of the DCXO registers to control frequency. In mode 2,
the user can set both registers to achieve better resolution while maintaining wide pull ranges.
Default Startup Condition
The SiT3907 starts up at its factory programmed frequency. The DCXO registers values are initialized all zeros,
effectively setting the frequency to the middle of the control range.
Frequency Control Protocol Description
The device includes two DCXO registers. Data for each register is written to the device using a data frame.
Data Frame Format
Each frame consists of 40 bits. A frame has 3 parts:
- The header, 16 bits
- Register address, 8 bits
- Pull frequency (PF) value represented as 2's complement binary number, 16 bits or 23 bits depending on programming mode
explained in the following paragraphs.
Most significant bits of a frame are sent first. When writing to both DCXO registers, the least significant word is sent first.
The header allows the devices to recognize that the master is initiating communication. The header includes the device
address, which is factory programmable. The valid header format is 0xFAIA, where "I" can be a hex digits from 0 to F. If not
specified at the order time, the device address will be defaulted to zero. For all examples and in this document, the device
address is considered to be zero (default).
Frequency Control Mode 1
In this resolution mode, only one frame per frequency update is
required, and the output frequency is updated at the end of each
frame. The length of the pull frequency data is 16 bits, and is written
to the device as shown below:
Frequency Control Mode 2
In this mode, two frames per frequency update are required, and fre-
quency is only updated at the end of the second frame. The pull fre-
quency value in this mode is 23 bits. This value is written to the
device in two frames as Figure 2. Note that register (address: 0x07)
carries the most significant 7 bits as indicated by the XXXXXXX in
Figure 2. The rest of the most significant bits must be set to 0.
Figure 1. Frequency Control Mode 1 Figure 2. Frequency Control Mode 2
Header
0xFA0A
(16 bits)
Pull Frequency Value
(16 bits)
Reg Address
0x06 or 0x07
(8 bits)
015 16 23 24 39
Header
(16 bits) 0xFA0A
Register
address
(8 bits) 0x06
Pull frequency value
(16 bits)
Header
(16 bits) 0xFA0A
Register
address
(8 bits) 0x07
Pull frequency value
(LS Word, 16 bits)
000000000xxxxxxx
Header
(16 bits) 0xFA0A
Register
address
(8 bits) 0x06
Pull frequency value
(MS word, 16 bits)
First frame
Second frame
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SiT3907
High Precision Digitally Controlled Oscillator (DCXO)
Rev. 1.2 Page 4 of 10 www.sitime.com
Figure 3. Mode 1 Frame Timing
Figure 4. Mode 2 Frame Timing
Frame Timing Parameters
Calculating Pull Frequency Values
The frequency control value must be encoded as a 2's complement number (16-bit in mode 1 and 23-bit in mode 2), represent-
ing the full scale range of the device. For example, for a ±1600ppm device in mode 2, the 23-bit number represents the full
±1600ppm range.
The upper 16 bits of the value are written to address 0x06. If the high-resolution register (address 0x07) is used, the other 7 bits
are written to the lowest seven bits of address 0x07.
Here are the steps to calculate the pull frequency (PF) value:
1. Find the scale factor (calculated for half of the pull range) from the tables below where PR is the Pull Range:
2. Enter the desired_PPM in equation below:
Frequency control (decimal value) = round (desired_PPM * K).
3. For any frequency shifts (positive or negative PPM), convert the frequency control value to a 2’s complement binary number.
Pull Range (PPM) Step Resolution (ppb)
Max Update Rate
(Updates Per Second) Pull Range (PPM) Step Resolution (ppb)
Max Update Rate
(Updates Per Second)
±25 1 25 K ±25 1 12.5 K
±50 1.5 25 K ±50 1 12.5 K
±100 3 25 K ±100 1 12.5 K
±200 6 25 K ±200 1 12.5 K
±400 12 25 K ±400 1 12.5 K
±800 25 25 K ±800 1 12.5 K
±1600 49 25 K ±1600 1 12.5 K
Table 1. Resolution and Update Rate for Mode 1 Table 2. Resolution and Update Rate for Mode 2
Parameter Symbol Min. Max. Unit
Frame Length Tframe 40 — S
Frame to Frame Delay Tf2f 2—S
Frequency Settling Time Tsettle —30S
Frame to Frequency Delay Tfdelay —8S
K (scale) Factor
Mode K = Scale Factor
1 (2^15-1) / (PR*1.00135625)
2(2^22-1) / (PR*1.00135625)
Tframe
Tfdelay
Tsettle
f0
Control pin
Output
frequency
f0 + PF1
f0 + PF2
0xPF10xPF2
0xFA0A 0x06 0xFA0A 0x06
Tf2f
Tframe
Tfdelay
Tsettle
f0
Control pin
Output
frequency
f0 + PF1
0xPF1
(LSB)
0xPF1
(MSB)
0xFA0A 0x07 0xFA0A 0x06
Tframe Tf2f
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SiT3907
High Precision Digitally Controlled Oscillator (DCXO)
Rev. 1.2 Page 5 of 10 www.sitime.com
Two examples follow:
Physical Interface
The SiTime DCMO uses a serial input interface to adjust the pull frequency value. The interface uses a one-wire tri-level
return-to-middle signaling format. Figure 5 below shows the signal waveform of the interface.
Figure 5. Serial 1-Wire Tri-Level Signaling
A logical bit “1” is defined by a high-logic followed by mid-logic. A logical bit “0” is defined by a low-logic followed by mid-logic.
The voltage ranges and time durations corresponding to low-logic, high-, and mid-logic are illustrated in Figure 5 and specified
in electrical specification table.
The overall baud rate is computed as below:
Figure 6 shows a simple circuit to generate tri-level circuit with a general purpose IO (GPIO) with tri-state capability. Most
FPGAs and micro controllers/processors include such GPIOs. If the GPIO does not support tri-state output, two IO s may be
used in combination with external tri-state buffer to generate the tri-level signal; an example of such buffer is the
SN74LVC1G126. The waveform at the output of the tri-state buffer is shown in Figure 7. When the GPIO drives Low or High
voltage, the rise/fall times are typically fast (sub-5ns range). When the output is set to Hi-Z, the output settles at middle voltage
with a RC response. The time constant is determined based on the total capacitance on frequency control pin and the parallel
resistance of the pull-up and pull-down resistors. The time constant in most practical situations will be less than 50ns; this
necessitate choosing longer T_middle to allow the RC waveform to settle within 5% or so.
Example 1
This example shows how to shift the frequency by +245.6 ppm in a
device with ±1600 pull range using Mode 2 (23-bit):
Decimal value: round(245.6 * K) = 642954
23-bit value = 0x09CF8A
LS Word value = 0x000A (to be written to address 0x07)
MS Word value = 0x139F (to be written to address 0x06)
Write LS Word: 0xFA0A 07 000A (Frequency will not update)
Write MS Word: 0xFA0A 06 139F (Frequency updates after write)
Example 2
This example shows how to shift the frequency by -831.2 ppm in a
device with ±1600 pull range using Mode 2 (23-bit):
Decimal value: round(abs(831.2 * K) = 2175989
23-bit abs binary value: 01000010011001111110101
23-bit 2's comp binary value: 1011110110011000 0001011
LS Word value = 0x 000B
MS Word value = 0x BD98
Write LS Word: 0xFA0A 07 000B (Frequency will not update)
Write MS Word: 0xFA0A 06 BD98 (Frequency updates after write)
bitT
ratebaud
_
1
_
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SiT3907
High Precision Digitally Controlled Oscillator (DCXO)
Rev. 1.2 Page 6 of 10 www.sitime.com
Figure 6. Circuit Diagram for Generating Tri-Level Signal with Tri-State Buffer
Figure 7. Tri-State Signal Generated with Tri-State Buffer
When using a tri-state buffer as shown above, care must be taken if the DATA and OE lines transition at the same time that
there are no glitches. A glitch might occur, for example, if the OE line enables the output slightly before the data line has fin-
ished its logical transition. One way around this, albeit at the cost of some data overhead, is to use an extra OE cycle on every
bit, as shown in Figure 8. Note that the diagram assumes an SN74LVC125, which has a low-true OE/ line (output is enabled
when OE/ is low). For a high-true OE part, such as the SN74LVC126, the polarity of that signal would be reversed.
Figure 8. Signal Polarity
VIH
VIL
VIM
DATA
OE/
Y
0x
F
0x
A
MI
H
LO
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SiT3907
High Precision Digitally Controlled Oscillator (DCXO)
Rev. 1.2 Page 7 of 10 www.sitime.com
Programmable Drive Strength
The SiT3907 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 de-
creasing (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 Applications Note
section; http://www.sitime.com/support/application-notes.
EMI Reduction by Slowing Rise/Fall Time
Figure 9 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 near-triangular 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.
Figure 9. 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
increase rise/fall time (edge rate) of the input clock. Some
chipsets would require faster rise/fall time in order to reduce
their sensitivity to this type of jitter. The SiT3907 provides up
to 3 additional high drive strength settings for very fast rise/fall
time. Refer to the Rise/Fall Time Tables to determine the
proper drive strength.
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 3.3V SiT3907 device with
default drive strength setting, the typical rise/fall time is 1.15ns
for 15 pF output load. The typical rise/fall time slows down to
2.72ns when the output load increases to 45 pF. One can
choose to speed up the rise/fall time to 1.41ns by then
increasing the drive strength setting on the SiT3907.
The SiT3907 can support up to 60 pF or higher in maximum
capacitive loads with up to 3 additional drive strength settings.
Refer to the Rise/Tall Time Tables to determine the proper
drive strength for the desired combination of output load vs.
rise/fall time
SiT3907 Drive Strength Selection
Tables 1 through 5 define the rise/fall time for a given capac-
itive load and supply voltage.
1. Select the table that matches the SiT3907 nominal supply
voltage (1.8V, 2.5V, 2.8V, 3.3V).
2. Select the capacitive load column that matches the appli-
cation 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.
Calculating Maximum Frequency
Based on the rise and fall time data given in Tables 1 through
4, the maximum frequency the oscillator can operate with
guaranteed full swing of the output voltage over temperature
as follows:
Where Trf_10/90 is the typical rise/fall time at 10% to 90% Vdd.
Example 1
Calculate fMAX for the following condition:
• Vdd = 1.8V (Table 1)
• Capacitive Load: 30 pF
• Typical Tr/f time = 5 ns (rise/fall time part number code = G)
1357911
-80
-70
-60
-50
-40
-30
-20
-10
0
10
Harmonic number
Harmonic amplitude (dB)
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
=1
3.5 x Trf_10/90
Max Frequency
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High Precision Digitally Controlled Oscillator (DCXO)
Rev. 1.2 Page 8 of 10 www.sitime.com
Rise/Fall Time (10% to 90%) vs CLOAD Tables
Table 3. Vdd = 1.8V Rise/Fall Times for Specific CLOAD Table 4. Vdd = 2.5V Rise/Fall Times for Specific CLOAD
Table 5. Vdd = 2.8V Rise/Fall Times for Specific CLOAD Table 6. Vdd = 3.3V Rise/Fall Times for Specific CLOAD
Drive Strength \ CLOAD 5 pF 15 pF 30 pF 45 pF 60 pF
L12.45 17.68 19.48 46.21 57.82
A6.50 10.27 16.21 23.92 30.73
R4.38 7.05 11.61 16.17 20.83
B3.27 5.30 8.89 12.18 15.75
S2.62 4.25 7.20 9.81 12.65
D2.19 3.52 6.00 8.31 10.59
T1.76 3.01 5.14 7.10 9.15
E1.59 2.59 4.49 6.25 7.98
U1.49 2.28 3.96 5.55 7.15
F1.22 2.10 3.57 5.00 6.46
W1.07 1.88 3.23 4.50 5.87
G1.01 1.64 2.95 4.12 5.40
X0.96 1.50 2.74 3.80 4.98
K0.92 1.41 2.56 3.52 4.64
Y0.88 1.34 2.39 3.25 4.32
Q0.86 1.29 2.24 3.04 4.06
Z or "-": Default 0.82 1.24 2.07 2.89 3.82
M0.77 1.20 1.94 2.72 3.61
N0.66 1.15 1.84 2.58 3.41
P0.51 1.09 1.76 2.45 3.24
Rise/Fall Time Typ (ns)
Drive Strength \ CLOAD 5 pF 15 pF 30 pF 45 pF 60 pF
L8.68 13.59 18.36 32.70 42.06
A4.42 7.18 11.93 16.60 21.38
R2.93 4.78 8.15 11.19 14.59
B2.21 3.57 6.19 8.55 11.04
S1.67 2.87 4.94 6.85 8.80
D1.50 2.33 4.11 5.68 7.33
T1.06 2.04 3.50 4.84 6.26
E0.98 1.69 3.03 4.20 5.51
U0.93 1.48 2.69 3.73 4.92
F0.90 1.37 2.44 3.34 4.42
W0.87 1.29 2.21 3.04 4.02
G or "-": Default 0.67 1.20 2.00 2.79 3.69
X0.44 1.10 1.86 2.56 3.43
K0.38 0.99 1.76 2.37 3.18
Y0.36 0.83 1.66 2.20 2.98
Q0.34 0.71 1.58 2.07 2.80
Z0.33 0.65 1.51 1.95 2.65
M0.32 0.62 1.44 1.85 2.50
N0.31 0.59 1.37 1.77 2.39
P0.30 0.57 1.29 1.70 2.28
Rise/Fall Time Typ (ns)
Drive Strength \ CLOAD 5 pF 15 pF 30 pF 45 pF 60 pF
L7.93 12.69 17.94 30.10 38.89
A4.06 6.66 11.04 15.31 19.80
R2.68 4.40 7.53 10.29 13.37
B2.00 3.25 5.66 7.84 10.11
S1.59 2.57 4.54 6.27 8.07
D1.19 2.14 3.76 5.21 6.72
T1.00 1.79 3.20 4.43 5.77
E0.94 1.51 2.78 3.84 5.06
U0.90 1.38 2.48 3.40 4.50
F0.87 1.29 2.21 3.03 4.05
W0.62 1.19 1.99 2.76 3.68
G or "-": Default 0.41 1.08 1.84 2.52 3.36
X0.37 0.96 1.72 2.33 3.15
K0.35 0.78 1.63 2.15 2.92
Y0.33 0.67 1.54 2.00 2.75
Q0.32 0.63 1.46 1.89 2.57
Z0.31 0.60 1.39 1.80 2.43
M0.30 0.57 1.31 1.72 2.30
N0.30 0.56 1.22 1.63 2.22
P0.29 0.54 1.13 1.55 2.13
Rise/Fall Time Typ (ns)
Drive Strength \ CLOAD 5 pF 15 pF 30 pF 45 pF 60 pF
L7.18 11.59 17.24 27.57 35.57
A3.61 6.02 10.19 13.98 18.10
R2.31 3.95 6.88 9.42 12.24
B1.65 2.92 5.12 7.10 9.17
S1.43 2.26 4.09 5.66 7.34
D1.01 1.91 3.38 4.69 6.14
T0.94 1.51 2.86 3.97 5.25
E0.90 1.36 2.50 3.46 4.58
U0.86 1.25 2.21 3.03 4.07
F or "-": Default 0.48 1.15 1.95 2.72 3.65
W0.38 1.04 1.77 2.47 3.31
G0.36 0.87 1.66 2.23 3.03
X0.34 0.70 1.56 2.04 2.80
K0.33 0.63 1.48 1.89 2.61
Y0.32 0.60 1.40 1.79 2.43
Q0.32 0.58 1.31 1.69 2.28
Z0.30 0.56 1.22 1.62 2.17
M0.30 0.55 1.12 1.54 2.07
N0.30 0.54 1.02 1.47 1.97
P0.29 0.52 0.95 1.41 1.90
Rise/Fall Time Typ (ns)
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SiT3907
High Precision Digitally Controlled Oscillator (DCXO)
Rev. 1.2 Page 9 of 10 www.sitime.com
Dimensions and Patterns
Packages (4-pin device)
Packages (6-pin device)
Notes:
5. Top marking: Y denotes manufacturing origin and XXXX denotes manufacturing lot number. The value of “Y” will depend on the assembly location of the device.
6. A capacitor of value 0.1 F between Vdd and GND is recommended.
Package Size – Dimensions (Unit: mm)[5] Recommended Land Pattern (Unit: mm)[6]
3.2 x 2.5 x 0.75 mm
Package Size – Dimensions (Unit: mm)[5] Recommended Land Pattern (Unit: mm)[6]
5.0 x 3.2 x 0.75 mm
7.0 x 5.0 x 0.90 mm
3.2 ± 0.15
2.5 ± 0.15
2.1
0.9
0.7
0.9
0.75 ± 0.05
#1
#2
#4#3
#2
#1
#3#4
YXXXX
2.2
1.9
1.4
1.2
0.75±0.05
YXXXX
1.20
#2
#5
#2
#5
#1#3
#4 #6
#1 #3
#4#6
5.0±0.10
1.40
1.10
5.08
7.0±0.10
2.60
#1 #3
#6 #4
XXXX
#1#3
#
6#4
0.85 ±0.15
#2
#5
#2
#
5
5.08
1.60
3.80
Rev. 1.2 Page 10 of 10 www.sitime.com
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The Smart Timing Choice
The Smart Timing Choice
High Precision Digitally Controlled Oscillator (DCXO)
SiT3907
Ordering Information
APR Definition
Absolute pull range (APR) = Nominal pull range (PR) - frequency stability (F_stab) - Aging (F_aging)
APR Table
Nominal Pull Range
Frequency Stability
± 10 ± 25 ±50
APR (PPM)
± 25 ± 10 — —
± 50 ± 35 ± 20 —
± 100 ± 85 ± 70 ± 45
± 200 ± 185 ± 170 ± 145
± 400 ± 385 ± 370 ± 345
± 800 ± 785 ± 770 ± 745
± 1600 ± 1585 ± 1570 ± 1545
SiT3907AC - 2F -33EH-75.123456T
Frequency
1.000000 to 220.000000 MHz
Part Family
“SiT3907”
Revision Letter
“A” is the revision
Temperature Range
“I” Industrial, -40 to 85ºC
Supply Voltage
“18” for 1.8 V ±5%
“25” for 2.5 V ±10%
“28” for 2.8 V ±10%
“33” for 3.3 V ±10%
Packaging
Blank for Bulk
Pull Range Options
“C” Commercial, -20 to 70ºC
Frequency Stability
“F” for ±10 PPM
“2” for ±25 PPM
Package
“C” 6-pin, 5.0 x 3.2 mm
“T”: Tape & Reel, 3K reel
“Y”: Tape & Reel, 1K reel
“D” 6-pin, 7.0 x 5.0 mm
Feature Pin (pin 2)
6-pin Device
“N” for No Connect
“3” for ±50 PPM
“M” for ±25 PPM
“B” for ±50 PPM
“E” for ±100 PPM
“H” for ±200 PPM
“X” for ±400 PPM
“Y” for ±800 PPM
“Z” for ±1600 PPM
“2” 4-pin, 3.2 x 2.5 mm
4-pin Device
“N” Not Available
Device Address
“-” for Address 0 (Default)
1 to F Hex numbers for other
possible addresses
Output Drive Strength
“–” Default (datasheet limits)
See Tables 1 to 5 for rise/fall
times
“L”
“A”
“R”
“B”
“S”
“D”
“T”
“E”
“U”
“F”
“W”
“G”
“X”
“K”
“Y”
“Q”
“Z”
“M”
“N”
“P”