Ordering Information .................................................................................................................................................................... 2
User Programming Interface ..................................................................................................................................... 18
Start-up output frequency and signaling types ........................................................................................................... 18
Any-frequency function ............................................................................................................................................. 19
C/SPI Control Registers...................................................................................................................................................... 28
9 I
Register Address: 0x00. DCO Frequency Control Least Significant Word (LSW) .................................................... 28
Register Address: 0x01. OE Control, DCO Frequency Control Most Significant Word (MSW) ................................. 29
Register Address: 0x02. DCO PULL RANGE CONTROL ........................................................................................ 29
Register Address: 0x03. Frac-N PLL Feedback Divider Integer Value and Frac-N PLL Feedback Divider Fraction
Value MSW ............................................................................................................................................................... 30
Register Address: 0x05. Forward Divider, Driver Control ......................................................................................... 30
Register Address: 0x06. Driver Divider, Driver Control ............................................................................................. 31
2
C Operation ........................................................................................................................................................................ 32
10 I
I
2
C protocol ............................................................................................................................................................... 32
I
2
C Timing Specification ............................................................................................................................................ 35
I
2
C Device Address Modes ....................................................................................................................................... 36
Dimensions and Patterns ........................................................................................................................................................... 43
Additional Information ................................................................................................................................................................ 44
Revision History ......................................................................................................................................................................... 45
Rev 1.01
Page 3 of 45
www.sitime.com
SiT3521
1 to 340 MHz Elite Platform I2C/SPI Programmable Oscillator
1 Electrical Characteristics
All Min and Max limits in the Electrical Characteristics tables are specified over temperature and rated operating voltage with
standard output terminations shown in the termination diagrams. Typical values are at 25°C and nominal supply voltage.
Table 1. Electrical Characteristics – Common to LVPECL, LVDS and HCSL
Parameter
Output Frequency Range
Symbol
f
Min.
1
Typ.
–
–
–
–
–
±1
–
–
–
Max.
340
Unit
MHz
Condition
Factory or user programmable, accurate to 6 decimal places
Frequency Range
Frequency Stability
Frequency Stability
F_stab
-10
-20
-25
-50
First Year Aging
F_1y
–
+10
+20
+25
+50
–
ppm
ppm
ppm
ppm
ppm
°C
°C
°C
1
st
-year aging at 25°C
Inclusive of initial tolerance, operating temperature, rated
power supply voltage and load variations.
Temperature Range
Operating Temperature Range
T_use
-20
-40
-40
+70
+85
+105
Supply Voltage
Supply Voltage
Vdd
2.97
2.7
2.52
2.25
3.3
3.0
2.8
2.5
–
–
100
–
–
–
3.63
3.3
3.08
2.75
–
30%
–
V
V
V
V
Extended Commercial
Industrial
Extended Industrial. Available only for I
2
C operation, not SPI.
Input Characteristics – OE Pin
Input Voltage High
Input Voltage Low
Input Pull-up Impedance
VIH
VIL
Z_in
70%
–
–
Vdd
Vdd
kΩ
OE pin
OE pin
OE pin, logic high or logic low
Output Characteristics
Duty Cycle
DC
45
–
–
55
%
Startup and Output Enable/Disable Timing
Start-up Time
Output Enable/Disable Time –
Hardware control via OE pin
Output Enable/Disable Time –
Software control via I
2
C/SPI
T_start
T_oe_hw
3.0
3.8
ms
µs
Measured from the time Vdd reaches its rated minimum value
Measured from the time OE pin reaches rated VIH and VIL to
the time clock pins reach 90% of swing and high-Z.
See
Figure 9
and
Figure 10
Measured from the time the last byte of command is
transmitted via I
2
C/SPI (reg1) to the time clock pins reach 90%
of swing and high-Z. See
Figure 30
and
Figure 31
T_oe_sw
–
–
6.5
µs
Rev 1.01
Page 4 of 45
www.sitime.com
SiT3521
1 to 340 MHz Elite Platform I2C/SPI Programmable Oscillator
Table 2. Electrical Characteristics – LVPECL Specific
Parameter
Symbol
Min.
Typ.
Max.
Unit
Condition
Current Consumption
Current Consumption
OE Disable Supply Current
Output Disable Leakage Current
Maximum Output Current
Idd
I_OE
I_leak
I_driver
–
–
–
–
–
–
0.15
–
89
58
–
32
mA
mA
A
mA
Excluding Load Termination Current, Vdd = 3.3 V or 2.5 V
OE = Low
OE = Low
Maximum average current drawn from OUT+ or OUT-
Output Characteristics
Output High Voltage
Output Low Voltage
Output Differential Voltage Swing
Rise/Fall Time
VOH
VOL
V_Swing
Tr, Tf
Vdd - 1.1V
Vdd - 1.9V
1.2
–
–
–
1.6
225
Vdd - 0.7V
Vdd - 1.5V
2.0
290
Jitter
RMS Phase Jitter (random) –
DCO Mode Only
T_phj
–
–
RMS Phase Jitter (random) –
Any-frequency Mode Only
T_phj
–
–
RMS Period Jitter
[3]
Note:
3. Measured according to JESD65B.
T_jitt
–
0.225
0.1
0.225
0.11
1
0.340
0.14
0.340
0.15
1.6
ps
ps
ps
ps
ps
f = 156.25 MHz, Integration bandwidth = 12 kHz to 20 MHz,
all Vdd levels
f = 156.25, IEEE802.3-2005 10 GbE jitter mask integration
bandwidth = 1.875 MHz to 20 MHz, all Vdd levels
f = 156.25 MHz, Integration bandwidth = 12 kHz to 20 MHz,
all Vdd levels
f = 156.25, IEEE802.3-2005 10 GbE jitter mask integration
bandwidth = 1.875 MHz to 20 MHz, all Vdd levels
f = 100, 156.25 or 212.5 MHz, Vdd = 3.3 V or 2.5 V
V
V
V
ps
See
Figure 5
See
Figure 5
See
Figure 6
20% to 80%, see
Figure 6
Table 3. Electrical Characteristics – LVDS Specific
Parameter
Symbol
Min.
Typ.
Max.
Unit
Condition
Current Consumption
Current Consumption
OE Disable Supply Current
Output Disable Leakage Current
Idd
I_OE
I_leak
–
–
–
–
–
0.15
80
61
–
mA
mA
A
Excluding Load Termination Current, Vdd = 3.3 V or 2.5 V
OE = Low
OE = Low
Output Characteristics
Differential Output Voltage
Delta VOD
Offset Voltage
Delta VOS
Rise/Fall Time
VOD
ΔVOD
VOS
ΔVOS
Tr, Tf
250
–
1.125
–
–
–
–
–
–
400
455
50
1.375
50
470
Jitter
RMS Phase Jitter (random) –
DCO Mode Only
T_phj
–
–
RMS Phase Jitter (random) –
Any-frequency Mode Only
T_phj
–
–
RMS Period Jitter
[4]
Note:
4. Measured according to JESD65B.
T_jitt
–
0.21
0.1
0.21
0.1
1
0.275
0.12
0.367
0.12
1.6
ps
ps
ps
ps
ps
f = 156.25 MHz, Integration bandwidth = 12 kHz to 20 MHz,
all Vdd levels
f = 156.25, IEEE802.3-2005 10 GbE jitter mask integration
bandwidth = 1.875 MHz to 20 MHz, all Vdd levels
f = 156.25 MHz, Integration bandwidth = 12 kHz to 20 MHz,
all Vdd levels
f = 156.25, IEEE802.3-2005 10 GbE jitter mask integration
bandwidth = 1.875 MHz to 20 MHz, all Vdd levels
f = 100, 156.25 or 212.5 MHz, Vdd = 3.3 V or 2.5 V
mV
mV
V
mV
ps
f = 156.25MHz See
Figure 7
See
Figure 7
See
Figure 7
See
Figure 7
Measured with 2 pF capacitive loading to GND, 20% to 80%,
I Hooked ZwCreateFile, and can print the directory name through DbgPrint("HookZwCreateFile:%wZ",ObjectAttributes->ObjectName);. Later I posted a question asking how to get the file name: http://topic....
I don't know where to post it, so I'll just talk about it here. I haven't thought about how to do it, but I heard that it's quite difficult to do DIY activities. I want to know the specific situation....
I want to write a program on ppc to communicate with a bluetooth module. I found the device on ppc and set the COM7 send port for it in the bluetooth manager of ppc. Then I wrote it like this in the s...
Designing a good current-to-voltage (transconductance amplifier) converter using a voltage feedback amplifier (VFA) is a major challenge. In theory, a photodiode can produce a current or voltage outpu...
Introduction to the principles of speech recognition technology
Automatic speech recognition (ASR) technology aims to enable computers to understand human speech and extract the textual inform...[Details]
Logic analyzers are widely used tools in digital design verification and debugging. They can verify the proper functioning of digital circuits and help users identify and troubleshoot faults. They ...[Details]
On August 22nd, Lantu Motors unveiled a new technology called "Lanhai Intelligent Hybrid" during a live broadcast of CCTV News' "Top Laboratory." The name sounds like another new term, but a closer...[Details]
Electric vehicles are now widespread, but they've brought with them a host of problems, the most prominent of which is charging. Small electric vehicles (EVs) are a new form of transportation in a ...[Details]
Electric vehicles are powered by electricity, and charging is a device that supplements the vehicle's energy source. It is common to need to recharge the vehicle when driving. But can you charge th...[Details]
SMT placement machines are important equipment in surface mount technology (Surface Mount Technology). Their performance has a decisive impact on the quality and efficiency of electronic manufactur...[Details]
1. Multi-channel DAC technology bottleneck
Currently,
the development of multi-channel DAC technology focuses on two core challenges.
First, industrial applications urgently ...[Details]
1. Fault phenomenon and cause analysis
1. During the operation of the equipment, the expansion sleeve is subjected to a large torque, and the mating surfaces of the shaft and the sleeve move...[Details]
Reflow soldering, as an electronics assembly process, has become a vital component of the electronics manufacturing industry. Choosing reflow soldering equipment is crucial for improving production...[Details]
In the field of intelligent driving, regulations are becoming increasingly stringent, and the technical threshold continues to rise. Especially after the traffic accident in March 2025, the Ministr...[Details]
In the field of communications power supplies, AC/DC rectifier power supplies are called primary power supplies or basic power supplies, while DC/DC converters are called secondary power supplies. ...[Details]
In daily life, when we purchase a transformer, we are faced with the installation and wiring procedures. Generally speaking, large transformers such as power transformers are equipped with speciali...[Details]
Previously, Positive Motion Technology shared with you the firmware upgrade of motion controller, ZBasic program development, ZPLC program development, communication with touch screen and input/out...[Details]
Common methods for troubleshooting roller press bearing wear include repair welding, thermal spraying, brush plating, and scrapping and replacement. However, these methods are often subject to asse...[Details]
We often hear about the precautions for using pure electric vehicles in winter, and many owners even develop relevant strategies, such as adopting a "charge as you go" principle for their vehicles,...[Details]