SI5380-D [SILICON]
Ultra-Low Phase Noise, 12-output JESD204B Clock Generator;型号: | SI5380-D |
厂家: | SILICON |
描述: | Ultra-Low Phase Noise, 12-output JESD204B Clock Generator |
文件: | 总53页 (文件大小:1431K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
Si5380 Rev D Data Sheet
Ultra-Low Phase Noise, 12-output JESD204B Clock Generator
KEY FEATURES
The Si5380 is a high performance, integer-based (M/N) clock generator for small cell
applications which demand the highest level of integration and phase noise perform-
• DSPLL eliminates external VCXO and
analog loop filter components
ance. Based on Silicon Laboratories’ 4th generation DSPLL™ technology, the Si5380
combines frequency synthesis and jitter attenuation in a highly integrated digital solu-
tion that eliminates the need for external VCXO and loop filter components. A low-cost,
fixed-frequency crystal provides frequency stability for free-run and holdover modes.
This all-digital solution provides superior performance that is highly immune to external
board disturbances such as power supply noise.
• Supports JESD204B clocking: DCLK and
SYSREF
• Ultra-low jitter of 65 fs
• Input frequency range:
• External Crystal: 54 MHz
• Differential: 11.52 MHz to 737.28 MHz
• LVCMOS: 11.52 MHz to 245.76 MHz
Applications:
• Output frequency range:
• Differential: 480 kHz to 1.47456 GHz
• JESD204B clock generation
• LVCMOS: 480 kHz to 245.76 MHz
• Status monitoring
• Remote Radio Units (RRU), Remote Access Networks (RAN), picocells, small cells
• Wireless base stations (3G, GSM, W-CDMA, 4G/LTE, LTE-A)
• Remote Radio Head (RRH), wireless repeaters, wireless backhaul
• Data conversion sampling clocks (ADC, DAC, DDC, DUC)
• Hitless switching
• Si5380: 4 input, 12 output, 64-QFN 9×9 mm
54 MHz XTAL
XA
XB
÷INT
OUT0A
OUT0
OUT1
OUT2
OSC
÷INT
÷INT
÷INT
÷INT
÷INT
Delay
Delay
Delay
Delay
Delay
IN0
IN1
IN2
÷INT
÷INT
÷INT
DSPLL
4 Input
Clocks
OUT3
OUT4
÷INT
÷INT
÷INT
÷INT
÷INT
÷INT
÷INT
Device and
System Clocks
OUT5
IN3/FB_IN
OUT6
OUT7
OUT8
OUT9
OUT9A
Status Flags
I2C / SPI
Status Monitor
Control
NVM
Si5380
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Rev. 1.0
Si5380 Rev D Data Sheet
Feature List
1. Feature List
The Si5380-D features are listed below:
• Digital frequency synthesis eliminates external VCXO and an-
alog loop filter components
• Adjustable output-output delay: 68 ps/step, ±128 steps
• Optional Zero Delay mode
• Supports JESD204B clocking: DCLK and SYSREF
• Ultra-low jitter:
• Independent output clock supply pins: 3.3, 2.5, or 1.8 V
• Core voltage:
• 65 fs typ (12 kHz to 20 MHz)
• Input frequency range:
• VDD = 1.8 V ±5%
• VDDA = 3.3 V ±5%
• Differential: 11.52 MHz to 737.28 MHz
• LVCMOS: 11.52 MHz to 245.76 MHz
• Output frequency range:
• Automatic free-run, lock, and holdover modes
• Programmable jitter attenuation bandwidth: 0.1 Hz to 100 Hz
• Hitless input clock switching
• Differential: up to 1.47456 GHz
• LVCMOS: up to 245.76 MHz
• Phase noise floor: –159 dBc/Hz
• Status monitoring (LOS, OOF, LOL)
• Serial interface: I2C or SPI In-circuit programmable with non-
volatile OTP memory
• Spur performance: –103 dBc max (relative to a 122.88 MHz
carrier)
ClockBuilderTM Pro software tool simplifies device configura-
tion
•
• Configurable outputs:
• Si5380: 4 input, 12 output, 64-QFN 9×9 mm
• Temperature range: –40 to +85 °C
• Pb-free, RoHS-6 compliant
• Signal swing: 200 to 3200 mVpp
• Compatible with LVDS, LVPECL
• LVCMOS 3.3, 2.5, or 1.8 V
• Output-output skew using same N-divider: 65 ps (Max)
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Si5380 Rev D Data Sheet
Ordering Guide
2. Ordering Guide
Table 2.1. Ordering Guide
Ordering Part Number
Number of
Outputs
Output Clock
Frequency
Range
Package
RoHS-6, Pb-Free
Temperature
Range
Si5380A-D-GM
12
0.480 MHz to
1464.56 MHz
64-Lead 9x9 mm QFN
Evaluation Board
Yes
–40 to +85 °C
Si5380-D-EVB
Note:
1. Add an “R” at the end of the device to denote tape and reel options.
2. Custom, factory pre-programmed devices are available. Ordering part numbers are assigned by ClockBuilder Pro. Part number
format is: Si5380A-Dxxxxx-GM, where “xxxxx” is a unique numerical sequence representing the pre-programmed configuration.
Figure 2.1. Ordering Part Number Fields
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Si5380 Rev D Data Sheet
Functional Description
3. Functional Description
The Si5380 is a high performance clock generator that is capable of synthesizing up to 10 unique integer related frequencies at any of
the device’s 12 outputs. The output clocks can be generated in free-run mode or synchronized to any one of the four external inputs.
Clock generation is provided by Silicon Laboratories’ 4th generation DSPLL technology which combines frequency synthesis and jitter
attenuation in a highly integrated digital solution that eliminates the need for external VCXO and loop filter components. The Si5380
device is fully configurable using the I2C or SPI serial interface and has in-circuit programmable non-volatile memory.
3.1 Frequency Configuration
The DSPLL provides the synthesis for generating the output clock frequencies which are synchronous to the selected input clock fre-
quency or free-running XTAL. It consists of a phase detector, a programmable digital loop filter, a high-performance ultra-low phase
noise analog 15 GHz VCO, and a user configurable feedback divider. An internal oscillator (OSC) provides the DSPLL with a stable
low-noise clock source for frequency synthesis and for maintaining frequency accuracy in the free-run or holdover modes. The oscillator
simply requires an external, low cost 54 MHz fundamental mode crystal to operate. No other external components are required for fre-
quency generation. A key feature of this DSPLL is that it provides immunity to external noise coupling from power supplies and other
uncontrolled noise sources that normally exist on printed circuit boards.
3.1.1 Si5380 LTE Frequency Configuration
The device’s frequency configuration is fully programmable through the serial interface and can also be stored in non-volatile memory.
The combination of flexible integer dividers and a high frequency VCO allows the device to generate multiple output clock frequencies
for applications that require ultra-low phase noise and spurious performance. At the core of the device are the N dividers which deter-
mine the number of unique frequencies that can be generated from the device. The table below shows a list of some possible output
frequencies for LTE applications. The Si5380’s DSPLL core can generate up to five unique top frequencies. These frequencies are dis-
tributed to the output dividers using a configurable crosspoint mux. The R dividers allow further division for up to 10 unique integer-ratio
related frequencies on the Si5380. The ClockBuilder Pro software utility provides a simple means of automatically calculating the opti-
mum divider values (P, M, N and R) for the frequencies listed in the table below.
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Si5380 Rev D Data Sheet
Functional Description
Table 3.1. Example of Possible LTE Clock Frequencies
FIN (MHz)1
LTE Device Clock Frequencies Fout (MHz)2
15.36
19.20
30.72
38.40
61.44
76.80
122.88
153.60
184.32
245.76
307.20
368.64
491.52
614.40
737.28
—
15.36
19.20
30.72
38.40
61.44
76.80
122.88
153.60
184.32
245.76
307.20
368.64
491.52
614.40
737.28
983.04
1228.80
1474.56
—
—
Note:
1. The Si5380 locks to any one of the frequencies listed in the FIN column and generates LTE device clock frequencies.
2. R output dividers allow other frequencies to be generated. These are useful for applications like JESD204B SYSREF clocks.
3.1.2 Si5380 Configuration for JESD204B Clock Generation
The Si5380 can be used as a high performance, fully integrated JEDEC JESD204B jitter cleaner while eliminating the need for discrete
VCXO and loop filter components. The Si5380 supports JESD204B subclass 0 and subclass 1 clocking by providing both device clocks
(DCLK) and system reference clocks (SYSREF). The 12 clock outputs can be independently configured as device clocks or SYSREF
clocks to drive JESD204B converters, FPGAs, or other logic devices. The Si5380 will clock up to four JESD204B targets using four or
more DCLKs and four SYSREF clocks with adjustable delay.Each DCLK is grouped with a SYSREF clock in this configuration.If SYS-
REF clocking is implemented in external logic, then the Si5380 will clock up to 12 JESD204B targets.Not limited to JESD204B applica-
tions, each of the 12 outputs is individually configurable as a high performance output for traditional clocking applications. An example
of a JESD204B frequency configuration is shown in the figure below. In this case, the N dividers determine the device clock frequency
and the R dividers provide the divided SYSREF clock which is used as the lower frequency frame clock. The N divider path also in-
cludes a configurable delay path (∆t) for controlling deterministic latency. The example shows a configuration where all the device
clocks are controlled by a single delay path (∆t0) while the SYSREF clocks each have their own independent delay paths (∆t1 – ∆t4),
though other combinations are also possible. Delay is programmable in steps of 68 ps in the range of ±128 steps (±8.6 ns). See the
3.5.14 Output Skew Control (Δt0 - Δt4) section for details on skew control. The SYSREF clock is always periodic and can be controlled
(on/off) without glitches by enabling or disabling its output through register writes.
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Si5380 Rev D Data Sheet
Functional Description
IN_SEL[1:0]
Si5380
IN0
IN0b
IN1
÷P0
÷P1
÷P2
÷P3
DSPLL
IN1b
PD LPF
IN2
IN2b
IN3/FB_IN
IN3b/FB_INb
÷M
÷5
VDDO0
OUT0A
OUT0Ab
÷R0A
÷R0
OUT0
OUT0b
VDDO5
OUT5
OUT5b
÷R5
÷R6
÷R7
÷R8
VDDO6
OUT6
OUT6b
Device
Clocks
t0
÷N0
VDDO7
OUT7
OUT7b
VDDO8
OUT8
OUT8b
OUT9
OUT9b
÷R9
OUT9A
OUT9Ab
÷R9A
VDDO9
VDDO1
OUT1
OUT1b
t1
t2
t3
t4
÷N1
÷N2
÷N3
÷N4
÷R1
÷R2
÷R3
÷R4
VDDO2
OUT2
OUT2b
SYSREF
Clocks
VDDO3
OUT3
OUT3b
VDDO4
OUT4
OUT4b
Figure 3.1. Example Divider Configuration for Generating JESD204B Subclass 1 Clocks
3.1.3 DSPLL Loop Bandwidth
The DSPLL loop bandwidth determines the amount of input clock jitter attenuation. Register configurable DSPLL loop bandwidth set-
tings in the range of 0.1 Hz to 100 Hz are available for selection. The DSPLL will always remain stable with less than 0.1 dB of peaking
regardless of the DSPLL loop bandwidth selection.
3.1.4 Fastlock
Selecting a low DSPLL loop bandwidth (e.g., 1 Hz) will generally lengthen the lock acquisition time. The fastlock feature allows setting a
temporary fastlock loop bandwidth that is used during the lock acquisition process. Higher fastlock loop bandwidth settings will enable
the DSPLL to lock faster. Once lock acquisition has completed, the DSPLL’s loop bandwidth will automatically revert to the DSPLL
Loop Bandwidth setting. Fastlock loop bandwidth settings in the range of 100 Hz to 4 kHz are available for selection. The fastlock fea-
ture can be enabled or disabled by register configuration.
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Si5380 Rev D Data Sheet
Functional Description
3.1.5 Modes of Operation
Once initialization is complete, the Si5380 operates in one of four modes: Free-run Mode, Lock Acquisition Mode, Locked Mode, or
Holdover Mode. A state diagram showing the modes of operation is shown in the figure below. The following sections describe each of
these modes in greater detail.
Power-Up
Reset and
Initialization
No valid
input clocks
selected
Free-run
Valid input clock
selected
Lock Acquisition
(Fast Lock)
Phase lock on
selected input
clock is achieved
An input is
qualified and
available for
selection
Locked
Mode
No valid input
clocks available
for selection
Holdover
Mode
Input Clock
Switch
Selected input
clock fails
Yes
No
Other Valid
Clock Inputs
Available?
Yes
Holdover
History
Valid?
No
Figure 3.2. Modes of Operation
3.1.6 Initialization and Reset
When power is applied, the device begins an initialization period where it downloads default register values and configuration data from
NVM and performs other initialization tasks. Communicating with the device through the serial interface is possible once this initializa-
tion period is complete. No clocks will be generated until the initialization is complete. There are two types of resets available. A hard
reset is functionally similar to a device power-up. All registers will be restored to the values stored in NVM and all circuits, including the
serial interface, will be restored to their initial state. A hard reset is initiated using the RSTb pin or by asserting the hard reset bit. A soft
reset bypasses the NVM download. It is simply used to initiate register configuration changes.
3.1.7 Freerun Mode
Once power is applied to the Si5380 and initialization is complete, the device will automatically enter freerun mode. Output clocks will
be generated on the outputs with their configured frequencies. The frequency accuracy of the generated output clocks in freerun mode
is dependent on the frequency accuracy of the external crystal or reference clock on the XA/XB pins. For example, if the crystal fre-
quency is ±100 ppm, then all the output clocks will be generated at their configured frequency ±100 ppm in freerun mode. Any change
or drift of the crystal frequency or external reference on the XA/XB pins will be tracked at the output clock frequencies.
3.1.8 Lock Acquisition
If a valid input clock is selected for synchronization, the DSPLL will automatically start the lock acquisition process. If the fast lock fea-
ture is enabled, the DSPLL will acquire lock using the Fastlock Loop Bandwidth setting and then transition to the DSPLL Loop Band-
width setting when lock acquisition is complete. During lock acquisition the outputs will generate a clock that follows the VCO frequency
change as it pulls-in to the input clock frequency.
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Si5380 Rev D Data Sheet
Functional Description
3.1.9 Locked Mode
Once lock is achieved, the Si5380 will generate output clocks that are both frequency and phase locked to the input clock. The DSPLL
will provide jitter attenuation of the input clock using the selected DSPLL loop bandwidth. At this point, any XTAL frequency drift inside
of the loop bandwidth will not affect the output frequencies. When lock is achieved, the LOLb pin will output a logic high level. The LOL
status bit and LOLb status pin will also indicate that the DSPLL is locked. See the 3.4.6 LOL Detection section for more details on LOLb
detection time.
3.1.10 Holdover Mode
The DSPLL will automatically enter holdover mode when the selected input clock becomes invalid and no other valid input clocks are
available for selection. The DSPLL uses an averaged input clock frequency as its final holdover frequency to minimize the disturbance
of the output clock phase and frequency when an input clock suddenly fails. The holdover circuit stores up to 120 seconds of historical
frequency data while the DSPLL is locked to a valid clock input. The final averaged holdover frequency value is calculated from a pro-
grammable window within the stored historical frequency data. Both the window size and the delay are programmable as shown in the
figure below. The window size determines the amount of holdover frequency averaging. The delay value allows ignoring frequency data
that may be corrupt just before the input clock failure.
Figure 3.3. Programmable Holdover Window
Clock Failure
and Entry into
Holdover
Historical Frequency Data Collected
time
Programmable historical data window
Programmable delay
used to determine the final holdover value
120s
0s
30ms, 60ms, 1s,10s, 30s, 60s
1s,10s, 30s, 60s
When entering holdover, the DSPLL will pull the output clock frequencies referred to the calculated averaged holdover frequency. While
in holdover, the output frequency drift is entirely dependent on the external crystal or external reference clock connected to the XA/XB
pins. If a new clock input becomes valid, the DSPLL will automatically exit the holdover mode and re-acquire lock to the new input
clock. This process involves pulling the output clock frequencies to achieve frequency and phase lock with the new input clock. This
pull-in process is glitchless and its rate is controlled by the DSPLL bandwidth and the Fastlock bandwidth. These options are register
programmable.
The DSPLL output frequency when exiting holdover can be ramped (recommend). Just before the exit is initiated, the difference be-
tween the current holdover frequency and the new desired frequency is measured. Using the calculated difference and a user-selecta-
ble ramp rate, the output is linearly ramped to the new frequency. The ramp rate can be 0.2 ppm/s, 40,000 ppm/s, or any of about 40
values in between. The DSPLL loop BW does not limit or affect ramp rate selections (and vice versa). CBPro defaults to ramped exit
from holdover. The same ramp rate settings are used for both exit from holdover and ramped input switching. For more information on
ramped input switching, see 3.3.5 Ramped Input Switching.
Note: If ramped holdover exit is not selected, the holdover exit is governed either by (1) the DSPLL loop BW or (2) a user-selectable
holdover exit BW.
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Si5380 Rev D Data Sheet
Functional Description
3.2 External Reference (XA/XB)
An external crystal (XTAL) is used in combination with the internal oscillator (OSC) to produce an ultra-low phase noise reference clock
for the DSPLL and for providing a stable reference for the free-run and holdover modes. A simplified diagram is shown in the figure
below. The Si5380 includes internal XTAL loading capacitors which eliminates the need for external capacitors and also has the benefit
of reduced noise coupling from external sources. Refer to the Table 5.12 Crystal Specifications on page 34 for crystal specifications.
A crystal frequency of 54 MHz is required, with a total accuracy of ±100 ppm* recommended for best performance. The Si5380 includes
built-in XTAL load capacitors (CL) of 8 pF, which are switched out of the circuit when using an external XO. The Si5380 Reference
Manual provides additional information on PCB layout recommendations for the crystal to ensure optimum jitter performance. To ach-
ieve optimal jitter performance and minimize BOM cost, a crystal is recommended on the XA/XB reference input. A clock (e.g., XO) may
be used in lieu of the crystal, but it may result in higher output jitter. See the Si5380 Reference Manual for more information. Selection
between the external XTAL or REFCLK is controlled by register configuration. The internal crystal loading capacitors (CL) are disabled
in this mode. It is important to note that when using the REFCLK option the phase noise of the outputs is directly affected by the phase
noise of the external XO reference. Refer to the Table 5.3 Input Clock Specifications on page 24 for REFCLK requirements when
using the REFCLK mode.
Note: Including initial frequency tolerance and frequency variation over the full operating temperature range, voltage range, load condi-
tions, and aging.
54MHz
XO
54MHz
XO
54MHz
XTAL
100
XA
XB
XA
XB
XA
XB
2xCL
2xCL
2xCL
2xCL
2xCL
2xCL
OSC
OSC
OSC
PREF
÷
PREF
PREF
÷
÷
Si5380
Si5380
Si5380
Crystal Resonator Connection
Differential XO Connection
Single-Ended XO Connection
Figure 3.4. XAXB Crystal Resonator and External Reference Clock Connection Options
3.3 Inputs (IN0, IN1, IN2, IN3/FB_IN)
Four clock inputs are available to synchronize the DSPLL. The inputs are compatible with both single-ended and differential signals.
Input selection can be manual (pin or register controlled) or automatic with definable priorities.
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Si5380 Rev D Data Sheet
Functional Description
3.3.1 Input Configuration and Terminations
Each of the inputs can be configured as differential or single-ended LVCMOS. The recommended input termination schemes are shown
in the figure below. Standard 50% duty cycle signals must be ac-coupled, while low duty cycle Pulsed CMOS signals can be DC-cou-
pled. Unused inputs can be disabled and left unconnected when not in use.
Standard AC-coupled Differential LVDS
Si5380
50
Standard
INx
100
3.3 V, 2.5 V
LVDS or
CML
INxb
50
Pulsed CMOS
Standard AC-coupled Differential LVPECL
Si5380
50
Standard
INx
100
INxb
50
3.3 V, 2.5 V
LVPECL
Pulsed CMOS
Standard AC-coupled Single-ended
Si5380
50
Standard
INx
3.3 V, 2.5 V, 1.8 V
LVCMOS
INxb
Pulsed CMOS
Pulsed CMOS DC-coupled Single-ended
Si5380
R1
Standard
INx
50
R2
INxb
3.3 V, 2.5 V, 1.8 V
LVCMOS
Pulsed CMOS
Resistor values for
fIN_PULSED < 1 MHz
VDD R1 (Ohm) R2 (Ohm)
1.8V
2.5V
3.3V
324
511
634
665
475
365
Figure 3.5. Termination of Differential and LVCMOS Input Signals
3.3.2 Manual Input Selection (IN0, IN1, IN2, IN3/FB_IN)
Input clock selection can be made manually using the IN_SEL[1:0] pins or through a register. A register bit determines input selection
as pin selectable or register selectable. The IN_SEL pins are selected by default. If there is no clock signal on the selected input, the
device will automatically enter free-run or holdover mode.
* NOTE: When the zero delay mode is enabled, IN3 becomes the feedback input (FB_IN) and is not available for selection as a clock
input.
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Si5380 Rev D Data Sheet
Functional Description
Table 3.2. Manual Input Selection Using IN_SEL[1:0] Pins
IN_SEL[1:0]
Selected Input
0
0
1
1
0
1
0
1
IN0
IN1
IN2
IN3*
3.3.3 Automatic Input Switching (IN0, IN1, IN2, IN3/FB_IN)
An automatic input selection state machine is available in addition to the manual switching option. In automatic mode, the selection
criteria is based on reference qualification, input priority, and the revertive option. Only references which are valid can be selected by
the automatic state machine. If there are no valid references available, the DSPLL will enter the holdover mode. With revertive switch-
ing enabled, the highest priority input with a valid reference is always selected. If an input with a higher priority becomes valid, then an
automatic switchover to that input will be initiated. With non-revertive switching, the active input will always remain selected while it is
valid. If it becomes invalid, an automatic switchover to a valid input with the highest priority will be initiated.
3.3.4 Hitless Input Switching
Hitless switching is a feature that prevents a phase transient from propagating to the output when switching between two frequency
locked clock inputs that have a fixed phase difference between them. A hitless switch can only occur when the two input frequencies
are frequency locked meaning that they have to be exactly at the same frequency, or have an integer frequency relationship to each
other. When this feature is enabled, the DSPLL simply absorbs the phase difference between the two input clocks during an input
switch. When disabled (normal switching), the phase difference between the two inputs is propagated to the output at a rate determined
by the DSPLL loop bandwidth.
3.3.5 Ramped Input Switching
When switching between two plesiochronous input clocks (i.e., the frequencies are "almost the same" but not quite), ramped input
switching should be enabled to ensure a smooth transition between the two inputs. Ramped input switching avoids frequency transients
and overshoot when switching between frequencies and so is the default switching mode in CBPro. The feature should be turned off
when switching between input clocks that are always frequency locked (i.e., are always the same exact frequency). The same ramp
rate settings are used for both holdover exit and clock switching. For more information on ramped exit from holdover, see 3.1.10 Hold-
over Mode.
3.3.6 Glitchless Input Switching
The DSPLL has the ability of switching between two input clocks that are up to 40 ppm apart in frequency. The DSPLL will pull-in to the
new frequency using the DSPLL loop bandwidth or using the Fastlock loop bandwidth if it is enabled. The loss of lock (LOL) indicator
will be asserted while the DSPLL is pulling-in to the new clock frequency. There will be no output runt pulses generated at the output.
Glitchless input switching is available regardless of whether the hitless switching feature is enabled or disabled.
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Si5380 Rev D Data Sheet
Functional Description
3.3.7 Zero Delay Mode
A zero delay mode is available for applications that require fixed and consistent minimum delay between the selected input and outputs.
The zero delay mode is configured by opening the internal feedback loop through software configuration and closing the loop externally
as shown in the figure below. This helps to cancel out the internal delay introduced by the dividers, the crosspoint, the input, and the
output drivers. Any one of the outputs can be fed back to the IN3/FB_IN pins, although using the output driver that achieves the short-
est trace length will help to minimize the input-to-output delay. The OUT9A and IN3/FB_IN pins are recommended for the external feed-
back connection. The FB_IN input pins must be terminated and ac-coupled when zero delay mode is used. A differential external feed-
back path connection is necessary for best performance. The order of the OUT9A and FB_IN polarities is such that they may be routed
on the device side of the PCB without requiring vias or needing to cross each other.
IN0
IN0b
IN1
Si5380
÷P0
÷P1
÷P2
DSPLL
IN1b
PD
LPF
IN2
IN2b
÷M
÷5
IN3/FB_IN
÷P3
VDDO0
IN3b/FB_INb
OUT0A
÷R0A
÷R0
OUT0Ab
OUT0
OUT0b
t0
t1
t2
t3
t4
÷N0
÷N1
÷N2
÷N3
÷N4
VDDO2
OUT2
OUT2b
÷R2
VDDO8
OUT8
OUT8b
÷R8
OUT9
OUT9b
÷R9
OUT9A
÷R9A
OUT9Ab
VDDO9
External Feedback Path
Figure 3.6. Si5380 Zero Delay Mode Set-up
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Si5380 Rev D Data Sheet
Functional Description
3.4 Fault Monitoring
All four input clocks (IN0, IN1, IN2, IN3/FB_IN) are monitored for loss of signal (LOS) and out-of-frequency (OOF) as shown in the fig-
ure below. The reference at the XA/XB pins is also monitored for LOS since it provides a critical reference clock for the DSPLL. The
DSPLL also has a Loss Of Lock (LOL) indicator, which is asserted when the DSPLL has lost synchronization with the selected input
clock.
XA XB
Si5380
OSC
LOS
XAXB
IN0
Precision
Fast
LOS
LOS
LOS
LOS
OOF
OOF
OOF
OOF
÷P0
÷P1
÷P2
÷P3
IN0b
DSPLL
IN1
Precision
Fast
LOL
IN1b
PD LPF
Precision
Fast
IN2
Feedback
Clock
IN2b
÷M
÷5
IN3/FB_IN
Precision
Fast
IN3b/FB_INb
Figure 3.7. Si5380 Fault Monitors
3.4.1 Input LOS Detection
The loss of signal monitor measures the period of each input clock cycle to detect phase irregularities or missing clock edges. Each of
the input LOS circuits have their own programmable sensitivity which allows ignoring missing edges or intermittent errors. Loss of signal
sensitivity is configurable using the ClockBuilder Pro utility. The LOS status for each of the monitors is accessible by reading a status
register. The live LOS register always displays the current LOS state and a sticky register always stays asserted until cleared. An option
to disable any of the LOS monitors is also available.
Sticky
Monitor
LOS
LOS
en
Live
Figure 3.8. LOS Status Indicators
3.4.2 XA/XB LOS Detection
An LOS monitor is available to ensure that the external crystal or reference clock is valid. By default, the output clocks are disabled
when XAXB LOS is detected. This feature can be disabled such that the device will continue to produce output clocks when XAXB LOS
is detected. See the 3.5.11 Output Disable During XAXB_LOS section for details.
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Functional Description
3.4.3 OOF Detection
Each input clock is monitored for frequency accuracy with respect to a OOF reference which it considers as its “0_ppm” reference. This
OOF reference can be selected as either: XAXB, IN0, IN1, IN2 or IN3. IN3 is only available as the OOF reference when not in ZDM.
The final OOF status is determined by the combination of both a precise OOF monitor and a fast OOF monitor as shown in the figure
below. An option to disable either monitor is also available. The live OOF register always displays the current OOF state, and its sticky
register bit stays asserted until cleared.
Sticky
Monitor
Precision
Fast
en
en
OOF
OOF
Live
Figure 3.9. OOF Status Indicator
3.4.4 Precision OOF Monitor
The Precision OOF monitor circuit measures the frequency of all input clocks to within ±1 ppm accuracy with respect to the frequency at
the XA/XB pins. The OOF monitor considers the frequency at the XA/XB pins as its 1/16 ppm OOF reference. A valid input frequency is
one that remains within the OOF frequency range which is register configurable up to ±500 ppm in steps of 1/16 ppm. A configurable
amount of hysteresis is also available to prevent the OOF status from toggling at the failure boundary. An example is shown in the
figure below. In this case the OOF monitor is configured with a valid frequency range of ±6 ppm and with 2 ppm of hysteresis. An option
to use one of the input pins (IN0–IN3) as the 0 ppm OOF reference instead of the XA/XB pins is available. This option is register config-
urable.
OOF Declared
OOF Cleared
fIN
Hysteresis
Hysteresis
-4 ppm
(Clear)
-6 ppm
(Set)
+4 ppm
(Clear)
+6 ppm
(Set)
0 ppm
OOF
Reference
Figure 3.10. Example of Precise OOF Monitor Assertion and De-assertion Triggers
3.4.5 Fast OOF Monitor
Because the precision OOF monitor needs to provide 1/16 ppm of frequency measurement accuracy, it must measure the monitored
input clock frequencies over a relatively long period of time. This may be too slow to detect an input clock that is quickly ramping in
frequency. An additional level of OOF monitoring called the Fast OOF monitor runs in parallel with the precision OOF monitors to quick-
ly detect a ramping input frequency. The Fast OOF monitor asserts OOF on an input clock frequency that has changed by 1,000 to
16,000 ppm.
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Functional Description
3.4.6 LOL Detection
A loss of lock (LOL) monitor asserts the LOL bit when the DSPLL has lost synchronization with the selected input clock. There is also a
dedicated active-low LOLb pin which reflects the loss of lock condition. The LOL monitor measures the frequency difference between
the input and feedback clocks at the phase detector. There are two LOL frequency monitors, one that sets the LOL indicator (LOL Set)
and another that clears the indicator (LOL Clear). A block diagram of the LOL monitor is shown in the figure below. The live LOL regis-
ter always displays the current LOL state and a sticky register always stays asserted until cleared. The LOLb pin reflects the current
state of the LOL monitor.
LOL Monitor
RS Latch
Sticky
LOL
Clear
Timer
Reset
LOL
LOL
Q
Live
LOL
Set
Set
LOLb
DSPLL
fIN
PD LPF
Feedback
Clock
÷M
÷5
Si5380
Figure 3.11. LOL Status Indicators
Each of the frequency monitors have adjustable sensitivity which is register configurable from 0.1 ppm to 10,000 ppm. Having two sep-
arate frequency monitors allows for hysteresis to help prevent chattering of LOL status. An example configuration where LOCK is indi-
cated when there is less than 0.1 ppm frequency difference at the inputs of the phase detector and LOL is indicated when there is more
than 1 ppm frequency difference is shown in the figure below.
Clear LOL
Threshold
Set LOL
Threshold
Lock Acquisition
LOL
Hysteresis
Lost Lock
LOCKED
0
0.1
1
10,000
Phase Detector Frequency Difference (ppm)
Figure 3.12. LOL Set and Clear Thresholds
An optional timer is available to delay clearing of the LOL indicator to allow additional time for the DSPLL to completely phase lock to
the input clock. The timer is also useful to prevent the LOL indicator from toggling or chattering as the DSPLL completes lock acquisi-
tion. The configurable delay value depends on frequency configuration and loop bandwidth of the DSPLL and is automatically calcula-
ted using the ClockBuilder Pro utility.
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Functional Description
3.4.7 Interrupt Pin INTRb
An interrupt pin INTRb indicates a change in state of the status indicators shown in the figure below. All of the status indicators are
maskable to prevent assertion of the interrupt pin. The state of the INTRb pin is reset by clearing the status register that caused the
interrupt. The sticky version of the fault monitors is used for this function to ensure that the fault condition is still available when re-
sponding to the interrupt.
Si5380
LOS_FLG 0x0012[0]
IN0
OOF_FLG 0x0012[4]
LOS_FLG 0x0012[1]
IN1
OOF_FLG 0x0012[5]
LOS_FLG 0x0012[2]
IN2
INTRb
OOF_FLG 0x0012[6]
LOS_FLG 0x0012[3]
IN3
OOF_FLG 0x0012[7]
LOL_FLG 0x0013[1]
HOLD_FLG 0x0013[5]
PLL
CAL_FLG 0x0014[5]
SYSINCAL_FLG 0x0011[0]
LOSXAXB_FLG 0x0011[1]
LOSREF_FLG 0x0011[2]
Device
XAXB_ERR_FLG 0x0011[3]
SMBUS_TIMEOUT_FLG 0x0011[5]
Figure 3.13. Interrupt Triggers and Masks
3.5 Outputs
The Si5380 supports 12 differential output drivers which can be independently configured as differential or LVCMOS.
3.5.1 Output Crosspoint
The output crosspoint allows any of the N dividers to connect to any of the clock outputs.
3.5.2 Output Signal Format
The differential output amplitude and common mode voltage are both fully programmable covering a wide variety of signal formats in-
cluding LVPECL, LVDS, HCSL, and CML. In addition to supporting differential signals, any of the outputs can be configured as
LVCMOS (3.3 V, 2.5 V, or 1.8 V) drivers providing up to 24 single-ended outputs, or any combination of differential and single-ended
outputs.
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Functional Description
3.5.3 Output Terminations
The output drivers support both ac-coupled and dc-coupled terminations as shown in the following figure.
AC-coupled LVDS/LVPECL
DC-coupled LVDS
V
DDO = 3.3 V, 2.5 V, 1.8 V
V
DDO = 3.3 V, 2.5 V
50
50
50
50
OUTx
OUTx
100
OUTxb
100
OUTxb
Internally
self-biased
Si5380
Si5380
AC-coupled LVPECL / CML
AC-coupled HCSL
VDDRX
VDD – 1.3 V
VDDO = 3.3 V, 2.5 V, 1.8 V
V
DDO = 3.3 V, 2.5 V
R1
R1
R2
50
50
OUTx
50
50
50
50
OUTx
Standard
HCSL
Receiver
OUTxb
OUTxb
Si5380
Si5380
R2
For VCM = 0.35 V
VDDRX
R1
R2
442 Ω
56.2 Ω
59 Ω
3.3 V
2.5 V
1.8 V
332 Ω
243 Ω
63.4 Ω
Figure 3.14. Supported Output Terminations
3.5.4 Programmable Common Mode Voltage For Differential Outputs
The common mode voltage (VCM) for the differential modes is programmable in 100 mV increments from 0.7 V to 2.3 V depending on
the voltage available at the output’s VDDO pin. Setting the common mode voltage is useful when dc-coupling the output drivers.
3.5.5 LVCMOS Output Terminations
LVCMOS outputs are dc-coupled with source-side series termination as shown in the figure below.
DC-coupled LVCMOS
3.3 V, 2.5 V, 1.8 V
LVCMOS
V
DDO = 3.3V, 2.5V, 1.8V
50
50
Rs
Rs
OUTx
OUTxb
Figure 3.15. LVCMOS Output Terminations
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Functional Description
3.5.6 LVCMOS Output Impedance and Drive Strength Selection
Each LVCMOS driver has a configurable output impedance to accommodate different trace impedances and drive strengths. A source
termination resistor is recommended to help match the selected output impedance to the trace impedance. There are three programma-
ble output impedance selections for each VDDO options as shown in the table below.
Table 3.3. Typical Output Impedance (ZS)
VDDO
CMOS_DRIVE_Selection
OUTx_CMOS_DRV = 1
OUTx_CMOS_DRV = 2
OUTx_CMOS_DRV = 3
3.3 V
2.5 V
1.8 V
38 Ω
43 Ω
—
30 Ω
35 Ω
46 Ω
22 Ω
24 Ω
31 Ω
3.5.7 LVCMOS Output Signal Swing
The signal swing (VOL/VOH) of the LVCMOS output drivers is set by the voltage on the VDDO pins. Each output driver has its own
VDDO pin allowing a unique output voltage swing for each of the LVCMOS drivers. OUT0 and OUT0A share the same VDDO pin.
OUT9 and OUT9A also share the VDDO pin. All other outputs have their own individual VDDO pins.
3.5.8 LVCMOS Output Polarity
When a driver is configured as an LVCMOS output it generates a clock signal on both pins (OUTx and OUTxb). By default the clock on
the OUTxb pin is generated with the same polarity (in phase) with the clock on the OUTx pin. The polarity of these clocks is configura-
ble enabling complimentary clock generation and/or inverted polarity with respect to other output drivers.
3.5.9 Output Enable/Disable
The OEb pin provides a convenient method of disabling or enabling all of the output drivers at the same time. When the OEb pin is held
high all outputs will be disabled. When held low, the outputs will all be enabled. Outputs in the enabled state can still be individually
disabled through register control.
3.5.10 Output Disable During LOL
By default, a DSPLL that is out of lock will generate either free-running clocks or generate clocks in holdover mode. There is an option
to disable the outputs when a DSPLL is LOL. This option can be useful to force a downstream PLL into holdover.
3.5.11 Output Disable During XAXB_LOS
The internal oscillator circuit (OSC) in combination with the external crystal (XTAL) provides a critical function for the operation of the
DSPLLs. In the event of a crystal failure, the device will assert an XAXB_LOS alarm. By default, all outputs will be disabled during
assertion of the XAXB_LOS alarm. There is an option to leave the outputs enabled during an XAXB_LOS alarm, but the frequency
accuracy and stability will be indeterminate during this fault condition.The internal oscillator circuit (OSC) in combination with the exter-
nal crystal (XTAL) provides a critical function for the operation of the DSPLLs. In the event of a crystal failure, the device will assert an
XAXB_LOS alarm. By default, all outputs will be disabled during assertion of the XAXB_LOS alarm. There is an option to leave the
outputs enabled during an XAXB_LOS alarm, but the frequency accuracy and stability will be indeterminate during this fault condition.
3.5.12 Output Driver State When Disabled
The disabled state of an output driver is configurable as either disable low or disable high.
3.5.13 Synchronous Enable/Disable Feature
The output drivers provide a selectable synchronous enable/disable feature. Output drivers with synchronous disable active will wait
until a clock period has completed before the driver is disabled or enabled. This prevents unwanted shortened pulses from occurring
when enabling or disabling an output. When this feature is turned off, the output clock will disable immediately without waiting for the
clock period to complete.
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Functional Description
3.5.14 Output Skew Control (Δt0 - Δt4)
The Si5380 uses independent dividers (N0 - N4) to generate up to 5 unique frequencies to its 12 outputs through a crosspoint switch. A
delay path (Δt0 - Δt4) associated with each of these dividers is available for applications that need a specific output skew configuration.
This is useful for compensating PCB trace delay differences or for applications that require quadrature clock generation. The resolution
of the phase adjustment is approximately 68 ps per step up to 128 steps of added phase delay (+8.6 ns late), or 128 steps of negative
delay (–8.6 ns early). Phase adjustments are register configurable. An example of generating two frequencies with unique configurable
path delays is shown in the following figure.
VDDO0
OUT0A
OUT0Ab
÷R0A
OUT0
OUT0b
÷R0
t0
t1
t2
t3
t4
÷N0
÷N1
÷N2
÷N3
÷N4
VDDO1
OUT1
÷R1
÷R2
÷R3
÷R4
÷R5
÷R6
÷R7
÷R8
OUT1b
VDDO2
OUT2
OUT2b
VDDO3
OUT3
OUT3b
VDDO4
OUT4
OUT4b
VDDO5
OUT5
OUT5b
VDDO6
OUT6
OUT6b
VDDO7
OUT7
OUT7b
VDDO8
OUT8
OUT8b
OUT9
OUT9b
÷R9
OUT9A
OUT9Ab
÷R9A
VDDO9
Figure 3.16. Example of Independently Configurable Path Delays
All phase delay values are restored to their default values after power-up, power-on reset, or hardware reset using the RSTb pin. Phase
delay default values can be written to NVM allowing a custom phase offset configuration at power-up or after power-on reset, or after a
hardware reset using the RSTb pin.
3.5.15 Output Divider (R) Synchronization
All the output R dividers are reset to a known state during the power-up initialization period. This ensures consistent and repeatable
phase alignment across all output drivers. Resetting the device using the RSTb pin or asserting the reset bit will have the same result.
Asserting the sync register bit provides another method of realigning the R dividers without resetting the device.
3.6 Power Management
Unused inputs and output drivers can be powered down when unused. Consult the Si5380 Reference Manual and ClockBuilder Pro
configuration utility for details.
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Functional Description
3.6.1 Power Down Pin (PDNb)
A power down pin is provided to force the device in a low power mode. The device’s configuration will be maintained but no output
clocks will be generated. Most of the internal blocks will be shut down but device communication via the serial interface will still be
available. When the PDNb pin is pulled low the outputs will shut down without glitching (the clock’s complete period will be generated
before shutting down). When PDNb is released the device will start generating clocks without glitches. The device will generate free-
running clocks until the DSPLL has acquired lock to the selected input clock source.
3.7 In-Circuit Programming
The Si5380 is fully configurable using the serial interface (I2C or SPI). At power-up, the device downloads its default register values
from internal non-volatile memory (NVM). Application specific default configurations can be written into NVM allowing the device to gen-
erate specific clock frequencies at power-up. Writing default values to NVM is in-circuit programmable with normal operating power sup-
ply voltages applied to its VDD and VDDA pins. The NVM is writable two times. Once a new configuration has been written to NVM, the
old configuration is no longer accessible. Refer to the Si5380 Reference Manual for a detailed procedure for writing registers to NVM.
3.8 Serial Interface
Configuration and operation of the Si5380 is controlled by reading and writing registers using the I2C or SPI interface. The I2C_SEL pin
selects I2C or SPI operation. The Si5380 supports communication with a 3.3 V or 1.8 V host by setting the IO_VDD_SEL configuration
bit. The SPI mode supports 4-wire or 3-wire by setting the SPI_3WIRE configuration bit. See the Si5380 Reference Manual for details.
3.9 Custom Factory Preprogrammed Devices
For applications where a serial interface is not available for programming the device, custom pre-programmed parts can be ordered
with a specific configuration written into NVM. A factory pre-programmed device will generate clocks at power-up. Custom, factory-pre-
programmed devices are available. Use the ClockBuilder Pro custom part number wizard (www.silabs.com/clockbuilderpro) to quickly
and easily request and generate a custom part number for your configuration.
In less than three minutes, you will be able to generate a custom part number with a detailed data sheet addendum matching your
design’s configuration. Once you receive the confirmation email with the data sheet addendum, simply place an order with your local
Silicon Labs sales representative. Samples of your pre-programmed device will ship to you typically within two weeks.
3.10 Enabling Features and/or Configuration Settings Not Available in ClockBuilder Pro for Factory Pre-programmed Devices
As with essentially all software utilities, ClockBuilder Pro is continuously updated and enhanced. By registering at www.silabs.com and
opting in for updates to software, you will be notified whenever changes are made and what the impact of those changes are. This
update process will ultimately enable ClockBuilder Pro users to access all features and register setting values documented in this data
sheet and the Si5380 Reference Manual .
However, if you must enable or access a feature or register setting value so that the device starts up with this feature or a register
setting, but the feature or register setting is NOT yet available in CBPro, you must contact a Silicon Labs applications engineer for as-
sistance. Examples of this type of feature or custom setting are the customizable output amplitude and common voltages for the clock
outputs. After careful review of your project file and custom requirements, all Silicon Labs applications engineer will email back your
CBPro project file with your specific features and register settings enabled, using what is referred to as the manual "settings override"
feature of CBPro. "Override" settings to match your request(s) will be listed in your design report file. Examples of setting "overrides" in
a CBPro design report are shown below:
Table 3.4. Setting Overrides
Location
0x0535[0]
0128[6:4]
Name
Type
No NVM
User
Target
N/A
Dec Value
Hex Value
0x1
FORCE_HOLD
OUT6_AMPL
1
5
OPN and EVB
0x5
Once you receive the updated design file, simply open it in CBPro. After you create a custom OPN, the device will begin operation after
startup with the values in the NVM file, including the Silicon Labs-supplied override settings.
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Functional Description
Place sample
Start
order
Do I need a
pre-programmed device
with a feature or setting
which is unavailable in
ClockBuilder Pro?
Generate
Custom OPN
in CBPro
Configure device
using CBPro
No
Yes
Contact Silicon Labs
Technical Support
to submit & review
your
Yes
non-standard
configuration
request & CBPro
project file
Receive
updated CBPro
project file
from
Silicon Labs
with “Settings
Override”
Does the updated
CBPro Project file
match your
Load project file
into CBPro and test
requirements?
Figure 3.17. Flowchart to Order Custom Parts with Features not Available in CBPro
Note: Contact Silicon Labs Technical Support at www.silabs.com/support/Pages/default.aspx.
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Si5380 Rev D Data Sheet
Register Map
4. Register Map
This document provides a brief list of available registers. For a complete list of registers and settings, please refer to the Si5380 Refer-
ence Manual .
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Si5380 Rev D Data Sheet
Electrical Specifications
5. Electrical Specifications
Table 5.1. Recommended Operating Conditions 1
Parameter
Ambient Temperature
Symbol
TA
Min
–40
—
Typ
25
Max
Unit
°C
°C
V
85
Maximum Junction Temperature
Core Supply Voltage
TJMAX
VDD
VDDA
VDDO
—
125
1.71
3.14
3.14
2.37
1.71
1.80
3.30
3.30
2.50
1.80
1.89
3.47
3.47
2.62
1.89
V
Output Driver Supply Voltage
V
V
V
Note:
1. All minimum and maximum specifications are guaranteed and apply across the recommended operating conditions. Typical val-
ues apply at nominal supply voltages and an operating temperature of 25 °C unless otherwise noted.
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Electrical Specifications
Table 5.2. DC Characteristics
Test Condition
Parameter
Symbol
IDD
Min
—
Typ
190
125
36
Max
310
135
41
Unit
mA
mA
mA
Core Supply Current 1,2
IDDA
—
Output Buffer Supply Current 2, 5
LVPECL Output 3
@ 1474.56 MHz
LVPECL Output 3
@ 153.6 MHz
IDDO
—
—
—
—
—
—
—
—
22
25
26
29
mA
mA
mA
mA
mA
mA
mW
LVDS Output 3
@ 1474.56 MHz
LVDS Output 3
15
18
@ 153.6 MHz
3.3 V LVCMOS Output 4
@ 153.6 MHz
22
30
2.5 V LVCMOS Output 4
@ 153.6 MHz
18
23
1.8 V LVCMOS Output 4
@ 153.6 MHz
12
16
Total Power Dissipation 1, 2
Pd
Typical Outputs
1300
1600
Notes:
1. Si5380 test configuration: 3 × 3.3 V LVPECL outputs enabled at 122.88 MHz, 2 × 3.3 V LVPECL outputs enabled at 491.52 MHz,
1 × 3.3 V LVPECL output enabled at 983.04 MHz. Excludes power in termination resistors.
2. Detailed power consumption for any configuration can be estimated using ClockBuilder Pro when an evaluation board (EVB) is
not available. All EVBs support detailed current measurements for any configuration.
3. Differential outputs terminated into an ac-coupled 100 Ω load.
4. LVCMOS outputs measured into a 5-inch 50 Ω PCB trace with 5 pF load. The LVCMOS outputs were set to
OUTx_CMOS_DRV=3, which is the strongest driver setting. Refer to the Si5380 Reference Manual for more details on register
settings.
5. VDDO0 supplies power to both OUT0 and OUT0A buffers. Similarly, VDDO9 supplies power to both OUT9 and OUT9A buffers.
LVCMOS Output Test Configuration
Differential Output Test Configuration
Trace length 5
inches
IDDO
0.1 uF
0.1 uF
56 Ω
0.1 uF
56 Ω
499 Ω
4.7 pF
50
IDDO
50 Ω Scope Input
50 Ω Scope Input
50
50
OUT
100
OUT
OUTb
OUTb
50
499 Ω
4.7 pF
0.1 uF
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Electrical Specifications
Table 5.3. Input Clock Specifications
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
Standard Input Buffer with Differential or Single-Ended/LVCMOS—AC-coupled (IN0, IN1, IN2, IN3/FB_IN)
Input Frequency Range
Voltage Swing1
fIN_DIFF
fIN_SE
Differential
11.52
11.52
—
—
737.28
245.76
MHz
MHz
All Single-ended Signals
(including LVCMOS)
Differential AC-coupled
FIN < 245.76 MHz
VIN
100
225
—
—
1800
1800
mVpp_se
mVpp_se
Differential AC-coupled
245.76 MHz < FIN
737.28 MHz
<
Single-Ended AC-coupled
FIN < 245.76 MHz
100
400
—
—
3600
—
mVpp_se
V/µs
Slew Rate 2, 3
Duty Cycle
SR
DC
CIN
RIN
40
—
—
—
0.3
16
60
—
—
%
pF
kΩ
Capacitance
Input Resistance
Pulsed CMOS Input Buffer—DC-coupled (IN0, IN1, IN2, IN3/FB_IN) 4
Input Frequency
fIN_PULSED_CM
11.52
—
245.76
MHz
OS
Input Voltage Thresholds4
VIL
VIH
SR
–0.2
0.8
—
—
—
0.4
—
V
V
Slew Rate 2, 3
400
—
V/µs
Duty Cycle
DC
PW
RIN
Clock Input
Pulse Input
40
1.6
—
—
—
8
60
—
—
%
ns
kΩ
Minimum Pulse Width
Input Resistance
REFCLK (applied to XA/XB)
REFCLK Frequency 5
fIN_REF
Frequency required for op-
timum performance
—
54
—
MHz
Total Frequency Tolerance 6
Input Voltage Swing
fRANGE
VIN_SE
VIN_DIFF
SR
–100
365
365
400
—
—
—
—
+100
2000
2500
—
ppm
mVpp_se
mVpp_diff
V/µs
Slew Rate 2 , 3
Imposed for best phase
noise performance
Input Duty Cycle
DC
40
—
60
%
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Si5380 Rev D Data Sheet
Electrical Specifications
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
Notes:
1. Voltage swing is specified as single-ended mVpp.
OUTx
Vcm
Vpp_se
Vpp_se
Vpp_diff = 2*Vpp_se
Vcm
OUTxb
2. Imposed for phase noise performance.
3. Rise and fall times can be estimated using the following simplified equation: tr/tf80-20 = ((0.8 – 0.2) * VIN_Vpp_se) / SR.
4. Pulsed CMOS mode is intended primarily for single-end LVCMOS input clocks < 1 MHz, which must be dc-coupled, having a duty
cycle significantly less than 50%. A common application example is a low frequency video frame sync pulse. Since the input
thresholds (VIL, VIH) of the input buffer are non-standard (0.40 and 0.80 V, respectively), refer to the input attenuator circuit for
dc-coupled Pulsed LVCMOS in the in the Si5380 Reference Manual . Otherwise, for standard LVCMOS input clocks, use the
"AC-coupled Single-Ended" mode as shown in Figure 3.14 Supported Output Terminations on page 16.
5. The REFCLK frequency for the Si5380 is fixed at 54 MHz. Contact Silicon Labs technical support for more information.
6. Includes initial tolerance, drift after reflow, change over temperature (–40 °C to +85 °C), VDD variation, load pulling, and aging.
Table 5.4. Serial and Control Input Pin Specifications
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
Si5380 Serial and Control Input Pins (I2C_SEL, IN_SEL[1:0], RSTb, OEb, SYNCb, PDNb, A1/SDO, SDA/SDIO, SCLK, A0/CSb)
Input Voltage Thresholds
VIL
VIH
—
—
—
0.3xVDDIO
—
1
V
V
0.7 x
VDDIO
1
Input Capacitance
Input Resistance
Minimum Pulse Width
Note:
CIN
IL
—
2
—
—
—
pF
kΩ
ns
—
20
—
PW
RSTb, SYNCb, PDNb
100
1. VDDIO is determined by the IO_VDD_SEL bit. It is selectable as VDDA or VDD. See the Si5380 Reference Manual for more details
on the register settings.
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Electrical Specifications
Table 5.5. Differential Clock Output Specifications
Parameter
Output Frequency
Symbol
fOUT
Test Condition
Min
0.480
48
Typ
—
Max
1474.56
52
Unit
MHz
%
Duty Cycle
DC
f ≤ 400 MHz
f > 400 MHz
—
45
—
55
%
Output-Output Skew
TSK
Outputs at 737.28 MHz
connected to the same
"N-divider"
—
—
65
ps
Outputs at 737.28 MHz
connected to different "N-di-
viders"
—
—
90
ps
OUT-OUTb Skew
TSK_OUT
Measured from the positive
to negative output pins
—
0
50
ps
Output Voltage Amplitude 1
VOUT
VDDO
=
LVDS
350
430
510
mVpp_se
3.3 V or
2.5 V or
1.8 V
VDDO = 3.3 V
or 2.5 V
LVPECL
640
750
900
Common Mode Voltage1
VCM
VDDO
=
LVDS
1.10
1.90
1.2
2.0
1.3
2.1
V
LVPECL
3.3 V
VDDO
=
LVPECL
LVDS
1.1
0.8
—
1.2
1.3
1.00
150
2.5 V
VDDO
=
sub-LVDS
0.9
1.8 V
Rise and Fall Times (20% to
80%)
tR/tF
100
ps
Differential Output Impedance
Power Supply Noise Rejection 2
ZO
—
—
—
—
—
—
100
–101
–96
–99
–97
–72
—
—
—
—
—
—
Ω
PSRR
10 kHz sinusoidal noise
100 kHz sinusoidal noise
500 kHz sinusoidal noise
1 MHz sinusoidal noise
dBc
dBc
dBc
dBc
dB
Output-Output Crosstalk3
XTALK
Measured spur from adja-
cent output
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Electrical Specifications
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
Notes:
1. Output amplitude and common mode voltage are programmable through register settings and can be stored in NVM. Each output
driver can be programmed independently. The maximum LVDS single-ended amplitude can be up to 110 mV higher than the TIA/
EIA-644 maximum. Refer to the Si5380 Reference Manual for recommended output register settings. Not all combinations of volt-
age amplitude and common mode voltages settings are possible.
2. Measured for 153.6 MHz carrier frequency. 100 mVpp of sinewave noise added to VDDO when programmed at 3.3 V.
3. Measured across two adjacent outputs, both in LVDS mode, with the victim running at 155.52 MHz and the aggressor at 156.25
MHz. These output frequencies are generated using non-production engineering modes only for test. Refer to application note,
"AN862: Optimizing Si534x Jitter Performance in Next Generation Internet Infrastructure Systems", for guidance on crosstalk opti-
mization. Note that all active outputs must be terminated when measuring crosstalk
Table 5.6. LVCMOS Clock Output Specifications
Parameter
Output Frequency
Duty Cycle
Symbol
Test Condition
Min
Typ
—
Max
245.76
52
Unit
MHz
%
0.480
DC
fOUT < 100 MHz
100 MHz < fOUT < 245.76 MHz
Outputs at 153.6 MHz
48
—
45
—
—
55
Output-to-Output Skew
TSK
30
140
ps
V
VDDO = 3.3 V
OUTx_CMOS_DRV=1
OUTx_CMOS_DRV=2
OUTx_CMOS_DRV=3
IOH = –10 mA
V
DDO x 0.85
—
—
—
—
—
—
IOH = –12 mA
IOH = –17 mA
VDDO = 2.5 V
VDDO x 0.85
Output Voltage High 1, 2, 3
VOH
OUTx_CMOS_DRV=1
OUTx_CMOS_DRV=2
OUTx_CMOS_DRV=3
IOH = –6 mA
IOH = –8 mA
IOH = –11 mA
—
—
—
—
—
—
V
V
VDDO = 1.8 V
VDDO x 0.85
OUTx_CMOS_DRV=2
OUTx_CMOS_DRV=3
IOH = –4 mA
IOH = –5 mA
—
—
—
—
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Electrical Specifications
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
VDDO = 3.3 V
OUTx_CMOS_DRV=1
IOL = 10 mA
IOL = 12 mA
IOL = 17 mA
—
—
—
—
VDDO x 0.15
V
OUTx_CMOS_DRV=2
OUTx_CMOS_DRV=3
—
—
VDDO = 2.5 V
Output Voltage Low 1, 2, 3
VOL
OUTx_CMOS_DRV=1
OUTx_CMOS_DRV=2
OUTx_CMOS_DRV=3
IOL = 6 mA
IOL = 8 mA
IOL = 11 mA
—
—
—
—
VDDO x 0.15
V
—
—
VDDO = 1.8 V
OUTx_CMOS_DRV=2
OUTx_CMOS_DRV=3
IOL = 4 mA
IOL = 5 mA
—
—
—
—
—
—
VDDO x 0.15
V
—
LVCMOS Rise and Fall
Times 3
tr/tf
VDDO = 3.3 V
400
450
550
600
600
750
ps
ps
ps
VDDO = 2.5 V
VDDO = 1.8 V
(20% to 80%)
Notes:
1. Driver strength is a register programmable setting and stored in NVM. Options are OUTx_CMOS_DRV = 1, 2, 3. Refer to the
Si5380 Reference Manual for recommended output register settings.
2. IOL/IOH is measured at VOL/VOH as shown in the DC test configuration
3. A 5 pF capacitive load is assumed. The LVCMOS outputs were set to OUTx_CMOS_DRV = 3.
AC Output Test Configuration
DC Test Configuration
Trace length 5 inches
0.1 uF
499 Ω
4.7 pF
IDDO
50
50
IOL/IOH
50 Ω Scope Input
50 Ω Scope Input
OUT
56 Ω
0.1 uF
Zs
OUTb
VOL/VOH
499 Ω
4.7 pF
56 Ω
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Electrical Specifications
Table 5.7. Output Serial and Status Pin Specifications
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
Si5380 Output Serial and Status Pins (LOLb, INTRb, SDA/SDIO2, A1/SDO)
Output Voltage 1, 2
VOH
IOH = –2 mA
IOL = 2 mA
VDDIO
0.85
x
—
—
—
V
V
VOL
—
VDDIO
0.15
x
Notes:
1. VDDIO is determined by the IO_VDD_SEL bit. It is selectable as VDDA or VDD. See the Si5380 Reference Manual for more details
on the register settings.
2. The VOH specification does not apply to the open-drain SDA/SDIO output when the serial interface is in I2C mode or is unused,
with I2C_SEL pulled high internally. VOL remains valid in all cases.
Table 5.8. Performance Characteristics
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
PLL Bandwidth Programming
Range 1
fBW
Bandwidth is register
programmable
0.1
—
4000
Hz
Initial Start-Up Time
tSTART
Time from power-up to
when the device gener-
ates free-running clocks
—
—
370
280
450
300
ms
ms
PLL Lock Time2
tACQ
Fastlock enabled
FIN = 19.2 MHz
POR to Serial Interface Ready 3
Output Delay Adjustment
tRDY
tDELAY_int
tRANGE
JPK
—
—
—
—
—
68
8.6
—
15
—
ms
ps
fVCO = 14.7456 GHz
±128 / fVCO
—
ns
Jitter Peaking
Measured with a frequen-
cy plan running a 24.576
MHz input, 24.576 MHz
output, and a Loop Band-
width of 4 Hz
0.1
dB
Jitter Tolerance
JTOL
Compliant with G.8262
Options 1 and 2 Carrier
Frequency = 2.103125
GHz; Jitter Modulation
Frequency = 10 Hz
—
3180
—
UI pk-pk
Maximum Phase Transient Dur-
ing a Hitless Switch
tSWITCH
Only valid for a single au-
tomatic switch between
two input clocks at same
frequency
—
—
—
—
—
2.0
1.3
20
ns
ns
Only valid for a single
manual switch between
two input clocks at same
frequency
Pull-in Range
ωP
–20
ppm
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Electrical Specifications
Parameter
Symbol
tIODELAY
tZDELAY
JGEN
Test Condition
Note 5
Min
—
Typ
—
Max
1.8
—
Unit
ns
Input-to-Output Delay Variation
Note 6
—
110
65
ps
RMS Phase Jitter 4
12 kHz to 20 MHz
—
80
fs rms
(measured @ 983.04
MHz)
Phase Noise Performance 4
PN
10Hz
100 Hz
—
—
—
—
—
—
—
—
—
–72
–98
—
—
—
—
—
—
—
—
—
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc
(122.88 MHz Carrier
Frequency)
1 kHz
–126
–140
–148
–154
–165
–103
–95
10 kHz
100 kHz
1 MHz
10 MHz
Spur Performance 4 (122.88
MHz Carrier Frequency)
SPUR
Up to 1 MHz offset
From 1 MHz to 30 MHz
offset
dBc
Notes:
1. Actual loop bandwidth might be lower; refer to ClockBuilder Pro for actual value on your frequency plan.
2. Lock Time can vary significantly depending on several parameters, such as bandwidths, LOL thresholds, etc. For this case, lock
time was measured with nominal and fastlock bandwidths both set to 100 Hz, LOL set/clear thresholds of 3/0.3 ppm respectively,
using IN0 as clock reference by removing the reference and enabling it again, then measuring the delta time between the first
rising edge of the clock reference and the LOL indicator de-assertion.
3. Measured as time from valid VDD/VDDA rails (both >90% of settled voltage) to when the serial interface is ready to respond to
commands.
4. Jitter generation test conditions: fIN = 30.72 MHz, 3.3V LVPECL, DSPLL LBW = 100 Hz. Jitter integrated from 12 kHz to 20 MHz
offset. Does not include jitter from PLL input reference.
5. Measured between a common 2 MHz input and 2 MHz output with different N-dividers on the same unit and a loop bandwidth of
4 kHz. These output frequencies are generated using non-production engineering modes only for test.
6. Delay between reference and feedback input both clocks at 10 MHz and same slew rate. Ref clock rise time must be <200 ps.
These output frequencies are generated using non-production engineering modes only for test.
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Electrical Specifications
Table 5.9. I2C Timing Specifications (SCL, SDA)
Parameter
Symbol
Test Condition
Standard Mode
100 kbps
Fast Mode
400 kbps
Min
Unit
Min
—
Max
100
35
Max
400
35
SCL Clock Frequency
SMBus Timeout
fSCL
—
—
kHz
ms
When Timeout is Ena-
bled
25
25
Hold Time (Repeated)
START Condition
tHD:STA
4.0
—
0.6
—
µs
Low Period of the SCL Clock
tLOW
tHIGH
4.7
4.0
—
—
1.3
0.6
—
—
µs
µs
HIGH Period of the SCL
Clock
Set-up Time for a Repeated
START Condition
tSU:STA
4.7
—
0.6
—
µs
Data Hold Time
tHD:DAT
tSU:DAT
tr
100
250
—
—
—
100
100
20
—
—
ns
ns
ns
Data Set-up Time
Rise Time of Both SDA and
SCL Signals
1000
300
Fall Time of Both SDA and
SCL Signals
tf
—
300
—
—
300
—
ns
µs
µs
Set-up Time for STOP Con-
dition
tSU:STO
4.0
4.7
0.6
1.3
Bus Free Time between a
tBUF
—
—
STOP and START Condition
Data Valid Time
tVD:DAT
tVD:ACK
—
—
3.45
3.45
—
—
0.9
0.9
µs
µs
Data Valid Acknowledge
Time
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Electrical Specifications
Figure 5.1. I2C Serial Prot Timing Standard and Fast Modes
Table 5.10. SPI Timing Specifications (4-Wire)
Parameter
Symbol
fSPI
Min
—
40
50
—
—
—
5
Typ
—
—
—
—
—
—
—
—
—
—
—
Max
20
60
—
Unit
MHz
%
SCLK Frequency
SCLK Duty Cycle
SCLK Period
TDC
TC
ns
Delay Time, SCLK Fall to SDO Active
Delay Time, SCLK Fall to SDO
Delay Time, CSb Rise to SDO Tri-State
Setup Time, CSb to SCLK
TD1
18
15
15
—
ns
TD2
ns
TD3
ns
TSU1
TH1
TSU2
TH2
ns
Hold Time, SCLK Fall to CSb
5
—
ns
Setup Time, SDI to SCLK Rise
Hold Time, SDI to SCLK Rise
5
—
ns
5
—
ns
Delay Time Between Chip Selects (CSb)
TCS
2
—
Tc
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Electrical Specifications
TSU1
TD1
TC
SCLK
CSb
TH1
TSU2
TH2
TCS
SDI
TD2
TD3
SDO
Figure 5.2. 4-Wire SPI Serial Interface Timing
Table 5.11. SPI Timing Specifications (3-Wire)
Parameter
Symbol
fSPI
Min
—
40
50
—
—
—
5
Typ
Max
20
60
—
Unit
MHz
%
SCLK Frequency
SCLK Duty Cycle
SCLK Period
—
—
—
—
—
—
—
—
—
—
—
TDC
TC
ns
Delay Time, SCLK Fall to SDIO Turn-on
Delay Time, SCLK Fall to SDIO Next-bit
Delay Time, CSb Rise to SDIO Tri-State
Setup Time, CSb to SCLK
TD1
20
15
15
—
ns
TD2
ns
TD3
ns
TSU1
TH1
TSU2
TH2
ns
Hold Time, SCLK Fall to CSb
5
—
ns
Setup Time, SDI to SCLK Rise
5
—
ns
Hold Time, SDI to SCLK Rise
5
—
ns
Delay Time Between Chip Selects (CSb)
TCS
2
—
Tc
TSU1
TC
SCLK
TH1
TD1
TD2
CSb
TSU2
TH2
TCS
SDIO
TD3
Figure 5.3. 3-Wire SPI Serial Interface Timing
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Si5380 Rev D Data Sheet
Electrical Specifications
Table 5.12. Crystal Specifications
Parameter
Crystal Frequency 1
Symbol
Test Condition
Min
Typ
Max
Unit
fXTAL
—
–100
—
54
—
MHz
Total Frequency Tolerance 2
Load Capacitance
fRANGE
CL
rESR
CO
—
8
+100
—
ppm
pF
Equivalent Series Resistance
Shunt Capacitance
Refer to the Family Reference Manual to determine ESR and shunt capacitance.
Crystal Drive Level
dL
The crystal resonator
must be able to tolerate
350 µW of drive level
—
—
350
µW
Notes:
1. See the Si5380 Reference Manual for a list of qualified 54 MHz crystals. The Si5380 is designed to work with crystals that meet
these specifications.
2. Includes initial tolerance, drift after reflow, change over temperature (–40 °C to +85 °C), VDD variation, load pulling, and aging.
Table 5.13. Thermal Characteristics 1
Parameter
Symbol
Test Condition
Value
Unit
Si5380–64QFN
Thermal Resistance
Junction to Ambient
ƟJA
Still Air
22
°C/W
Air Flow 1 m/s
Air Flow 2 m/s
19.4
18.3
9.5
Thermal Resistance
Junction to Case
Thermal Resistance
Junction to Board
Thermal Resistance
Junction to Board
Thermal Resistance
Junction to Top Center
Note:
ƟJC
ƟJB
ΨJB
ΨJT
9.4
9.3
0.2
1. Based on PCB Dimension: 3x4.5”, PCB Thickness: 1.6 mm, PCB Land/Via: 36, Number of Cu Layers: 4.
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Electrical Specifications
Table 5.14. Absolute Maximum Ratings 1, 2, 3, 4
Parameter
DC Supply Voltage
Symbol
VDD
Test Condition
Value
Unit
V
–0.5 to 3.8
–0.5 to 3.8
–0.5 to 3.8
–0.85 to 3.8
–0.5 to 3.8
VDDA
VDDO
V
V
5
Input Voltage Range
VI1
IN0-IN3/FB_IN
IN_SEL[1:0],
V
VI2
RSTb, PDNb,OEb, SYNCb,
I2C_SEL, SCLK,
A0/CSb, A1/SDO,
SDA/SDIO
VI3
LU
XA/XB
–0.5 to 2.7
V
Latch-up Tolerance
JESD78 Compliant
ESD Tolerance
HBM
TSTG
TJCT
TPEAK
100 pF, 1.5 kΩ
2.0
–55 to 150
125
kV
°C
°C
°C
Storage Temperature Range
Max Junction Temperature in Operation
Soldering Temperature (Pb-free profile) 4
260
Soldering Temperature Time at TPEAK (Pb-
free profile) 4
TP
20 to 40
sec
Notes:
1. Permanent device damage may occur if the absolute maximum ratings are exceeded. Functional operation should be restricted to
the conditions as specified in the operational sections of this data sheet. Exposure to absolute maximum rating conditions for ex-
tended periods may affect device reliability.
2. 64-QFN is RoHS-6 compliant.
3. For MSL rating and additional packaging information, go to http://www.silabs.com/support/quality/pages/RoHSInformation.aspx.
4. The device is compliant with JEDEC J-STD-020.
5. The minimum voltage at these pins can be as low as -1.0 V when an AC input signal is applied. See Table 5.3 Input Clock Speci-
fications on page 24 spec for Single-ended AC-coupled fIN < 245.76 MHz.
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Si5380 Rev D Data Sheet
Typical Application Diagrams
6. Typical Application Diagrams
IEEE
1588
GPS
N
N
Rx
ADC
ADC
LNA
0
90
CPRI
Stratum 3/
3E DPLL
ASIC
ASIC
Tx
PA
N
N
DAC
DAC
0
90
OCXO
RF
Synth
Recovered Clock
30.72MHz x N
Base Band Unit
LTE
Sampling
Clocks
RF
Synth
Remote Radio
Head
Figure 6.1. LTE Base Station Remote Radio Head
IEEE
1588
JESD
204B
GPS
Rx
A/D
LNA
0
90
JESD
204B
A/D
CPRI
Stratum 3/
3E DPLL
Tx
ASIC
JESD
204B
ASIC
PA
D/A
0
90
JESD
204B
OCXO
D/A
RF
Synth
Base Band Unit
RF
Synth
DCLK
SYSREF
DCLK
SYSREF
DCLK
SYSREF
Remote Radio
Head
Recovered Clock
30.72MHz x N
Figure 6.2. LTE Base Station Using JESD204B Data Converters
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Si5380 Rev D Data Sheet
Detailed Block Diagram
7. Detailed Block Diagram
54MHz
XTAL
Si5380
XA
XB
IN_SEL
OSC
÷R0A
OUT0A
÷P0
÷P1
÷P2
IN0
IN1
IN2
÷R0
÷R1
÷R2
÷R3
÷R4
OUT0
OUT1
OUT2
OUT3
OUT4
OUT5
OUT6
OUT7
DSPLL
IN3/
FB_IN
÷P3
t0
÷N0
I2C_SEL
SDA/SDI
A1/SDO
SCLK
t1
÷N1
I2C/
SPI
÷R5
÷R6
÷R7
÷N2
÷N3
t2
A0/CSb
NVM
t3
t4
÷N4
÷R8
÷R9
OUT8
OUT9
INTRb
LOLb
Status Monitor
÷R9A
OUT9A
SYNCb
OEb
PDNb
RSTb
Figure 7.1. Si5380 Block Diagram
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Si5380 Rev D Data Sheet
Typical Operating Characteristics (Phase Noise & Jitter)
8. Typical Operating Characteristics (Phase Noise & Jitter)
Figure 8.1. Input = 61.44 MHz; Output = 983.04 MHz, 3.3 V LVPECL
Figure 8.2. Input = 61.44 MHz; Output = 1,474.56 MHz, 3.3 V LVPECL
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Typical Operating Characteristics (Phase Noise & Jitter)
Figure 8.3. Input = 61.44 MHz; Output = 245.76 MHz, 3.3 V LVPECL
Figure 8.4. Input = 61.44 MHz; Output = 122.88 MHz, 3.3 V LVPECL
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Si5380 Rev D Data Sheet
Pin Description
9. Pin Description
48 SYNCb
1
2
IN1
IN1b
47
LOLb
46
3
VDD
IN_SEL0
IN_SEL1
PDNb
RSTb
X1
45
4
OUT6
44
5
OUT6b
43
6
VDDO6
42
7
OUT5
41
40
39
38
37
36
35
34
33
8
OUT5b
VDDO5
I2C_SEL
OUT4
XA
GND
Pad
9
XB
10
11
12
13
14
15
16
X2
OEb
OUT4b
VDDO4
OUT3
INTRb
VDDA
IN2
OUT3b
VDDO3
IN2b
SCLK
Figure 9.1. Si5380 64-QFN Top View
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Si5380 Rev D Data Sheet
Pin Description
Table 9.1. Pin Descriptions
Pin Type1
Pin Name
Pin Number
Function
XA
XB
8
9
I
I
Crystal Input. Input pin for external crystal (XTAL). Alterna-
tively these pins can be driven with an external reference
clock (REFCLK). An internal register bit selects XTAL or
REFCLK mode. Default is XTAL mode. Single-ended inputs
must be connected to the XA pin, with the XB pin appropri-
ately terminated.
X1
X2
7
I
I
XTAL Shield. Connect these pins directly to the crystal
ground pins. Both the X1/X2 pins and Crystal ground pins
should be separated from the PCB ground plane. Refer to
the Reference Manual for layout guidelines.
10
IN0
IN0b
63
64
1
I
I
I
I
I
I
I
I
Clock Inputs. These pins accept an input clock for syn-
chronizing the device. They support both differential and
single-ended clock signals. Refer to 3.3.1 Input Configura-
tion and Terminations for input termination options. These
pins are high-impedance and must be terminated externally,
when being used. The negative side of the differential input
must be ac-grounded when accepting a single-ended clock.
Unused inputs may be left unconnected.
IN1
IN1b
2
IN2
14
15
61
62
IN2b
IN3/FB_IN
IN3b/FB_INb
Clock Input 3/External Feedback Input.
By default, these pins are used as the 4th clock input (IN3/
IN3b). They can also be used as the external feedback in-
put (FB_IN/FB_INb) for the optional zero delay mode. See
section 5.3.6 for details on the optional zero delay mode.
Outputs
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Si5380 Rev D Data Sheet
Pin Description
Pin Type1
Pin Name
Pin Number
Function
OUT0A
OUT0Ab
OUT0
21
20
24
23
28
27
31
30
35
34
38
37
42
41
45
44
51
50
54
53
56
55
59
58
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
Output Clocks. These output clocks support programma-
ble signal amplitude and common mode voltage. Desired
output signal format is configurable using register control.
Termination recommendations are provided in
3.5.5 LVCMOS Output Terminations. Unused outputs
should be left unconnected.
OUT0b
OUT1
OUT1b
OUT2
OUT2b
OUT3
OUT3b
OUT4
OUT4b
OUT5
OUT5b
OUT6
OUT6b
OUT7
OUT7b
OUT8
OUT8b
OUT9
OUT9b
OUT9A
OUT9Ab
Serial Interface
I2C_SEL
I2C Select. This pin selects the serial interface mode as I2C
(I2C_SEL = 1) or SPI (I2C_SEL = 0). This pin is internally
pulled high.
39
18
I
SDA/SDIO
I/O
Serial Data Interface. This is the bidirectional data pin
(SDA) for the I2C mode, the bidirectional data pin (SDIO) in
the 3-wire SPI mode, or the input data pin (SDI) in 4-wire
SPI mode. When in I2C mode or unused, this pin must be
pulled-up using an external resistor of >= 1 kΩ. No pull-up
resistor is needed when in SPI mode.
Address Select 1/Serial Data Output. In I2C mode this pin
functions as the A1 address input pin. In 4-wire SPI mode,
this is the serial data output (SDO) pin. This pin should be
externally pulled up or down when unused.
A1/SDO
SCLK
17
16
I/O
I
Serial Clock Input. This pin functions as the serial clock in-
put for both I2C and SPI modes. When in I2C mode or un-
used, this pin must be pulled-up using an external resistor
of >= 1 kΩ. No pull-up resistor is needed when in SPI mode.
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Si5380 Rev D Data Sheet
Pin Description
Pin Type1
Pin Name
Pin Number
Function
A0/CSb
19
I
Address Select 0/Chip Select. This pin functions as the
hardware controlled address A0 in I2C mode. In SPI mode,
this pin functions as the chip select input (active low). This
pin is internally pulled-up.
Control/Status
Interrupt. 2 This pin is asserted low when a change in de-
vice status has occurred. This pin must be pulled-up exter-
nally using a resistor of >= 1 kΩ. It should be left unconnec-
ted when not in use.
INTRb
12
O
Power Down. 2 The device enters into a low power mode
when this pin is pulled low. This pin is internally pulled-up. It
can be left unconnected when not in use.
PDNb
RSTb
5
6
I
I
Device Reset. 2 Active low input that performs power-on re-
set (POR) of the device. Resets all internal logic to a known
state and forces the device registers to their default values.
Clock outputs are disabled during reset. This pin is internal-
ly pulled-up.
Output Enable. 2 This pin disables all outputs when held
high. This pin is internally pulled low and can be left uncon-
nected when not in use.
OEb
11
47
I
Loss Of Lock. 2 This output pin indicates when the DSPLL
is locked (high) or out-of-lock (low). When in use, this pin
must be pulled-up using an external resistor of >= 1 kΩ. It
can be left unconnected when not in use.
LOLb
O
Output Clock Synchronization. 2 An active low signal on
this pin resets the output dividers for the purpose of re-
aligning the output clocks. This pin is internally pulled-up
and can be left unconnected when not in use.
SYNCb
48
I
Input Reference Select. 2 The IN_SEL[1:0] pins are used
in manual pin controlled mode to select the active clock in-
put as shown in Table 3.2 Table 6.2 on page 10. These pins
are internally pulled-down and may be left unconnected
when unused.
IN_SEL0
IN_SEL1
3
4
I
I
RSVD
Power
VDD
25
Reserved. Leave disconnected.
32
46
60
13
P
P
P
P
Core Supply Voltage. The device operates from a 1.8 V
supply. A 1 µF bypass capacitor should be placed very
close to each pin.
VDD
VDD
VDDA
Core Supply Voltage 3.3 V. This core supply pin requires a
3.3 V power source. A 1 µF bypass capacitor should be
placed very close to this pin.
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Rev. 1.0 | 43
Si5380 Rev D Data Sheet
Pin Description
Pin Type1
Pin Name
Pin Number
Function
VDDO0
VDDO1
VDDO2
VDDO3
VDDO4
VDDO5
VDDO6
VDDO7
VDDO8
VDDO9
GND PAD
22
26
29
33
36
40
43
49
52
57
P
P
P
P
P
P
P
P
P
P
P
Output Clock Supply Voltage. Supply voltage (3.3 V, 2.5
V, 1.8 V) for OUTx, OUTxb Outputs. Note that VDDO0
supplies power to OUT0 and OUT0A; VDDO9 supplies
power to OUT9 and OUT9A. Leave VDDO pins of unused
output drivers unconnected. An alternative option is to con-
nect the VDDO pin to a power supply and disable the output
driver to minimize current consumption. A 1 µF bypass ca-
pacitor should be placed very close to each connected
VDDO pin.
Ground Pad. This pad provides connection to ground and
must be connected for proper operation.
Note:
1. I = Input, O = Output, P = Power
2. The IO_VDD_SEL control bit (0x0943 bit 0) selects 3.3 V or 1.8 V operation.
3. All status pins except I2C and SPI are push-pull.
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Rev. 1.0 | 44
Si5380 Rev D Data Sheet
Package Outline
10. Package Outline
Figure 10.1. Si5380 9x9 mm 64-QFN Package Diagram
Table 10.1. Package Diagram Dimensions
Dimension
MIN
0.80
0.00
0.18
NOM
0.85
MAX
0.90
0.05
0.30
A
A1
0.02
b
0.25
D
9.00 BSC
5.20
D2
5.10
5.30
e
0.50 BSC
9.00 BSC
5.20
E
E2
5.10
0.30
—
5.30
0.50
0.15
0.10
0.08
0.10
L
0.40
aaa
—
bbb
—
—
ccc
—
—
ddd
—
—
Note:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.
3. This drawing conforms to the JEDEC Solid State Outline MO-220.
4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components.
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Rev. 1.0 | 45
Si5380 Rev D Data Sheet
PCB Land Pattern
11. PCB Land Pattern
Figure 11.1. 9x9 mm 64-QFN Land Pattern
Table 11.1. PCB Land Pattern Dimensions
Dimension
Max
8.90
8.90
0.50
0.30
0.85
5.30
5.30
C1
C2
E
X1
Y1
X2
Y2
Notes:
General
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. This Land Pattern Design is based on the IPC-7351 guidelines.
3. All dimensions shown are at Maximum Material Condition (MMC). Least Material Condition is calculated based on a fabrication
Allowance of 0.05 mm.
Solder Mask Design
1. All metal pads are to be non-solder mask defined (NSMD). Clearance between the solder mask and the metal pad is to be 60 μm
minimum, all the way around the pad.
Stencil Design
1. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should be used to assure good solder paste release.
2. The stencil thickness should be 0.125 mm (5 mils).
3. The ratio of stencil aperture to land pad size should be 1:1 for all perimeter pads.
4. A 3x3 array of 1.25 mm square openings on 1.80 mm pitch should be used for the center ground pad.
Card Assembly
1. A No-Clean, Type-3 solder paste is recommended.
2. The recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components.
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Rev. 1.0 | 46
Si5380 Rev D Data Sheet
Top Marking
12. Top Marking
Si5380A-
Rxxxxx-GM
YYWWTTTTTT
e4
TW
64-QFN
Figure 12.1. Si5380 Top Marking
Table 12.1. Top Marking Explanation
Line
Characters
Description
1
Si5380A-
Base part number for Ultra Low Phase Noise, 12-output JESD204B Clock Generator:
Si5380A: 12-output clock generator; 64-QFN
– = Dash character.
2
Rxxxxx-GM
R = Product revision. (See Ordering Guide for current ordering revision).
xxxxx = Customer specific NVM sequence number. Optional NVM code assigned for
custom, factory pre-programmed devices.
Characters are not included for standard, factory default configured devices. See Or-
dering Guide for more information.
-GM = Package (QFN) type and temperature range (–40 to +85 °C).
3
YYWWTTTTTT
YYWW = Characters correspond to the year (YY) and work week (WW) of package
assembly.
TTTTTT = Manufacturing trace code.
Pin 1 indicator; left-justified
4
Circle w/ 1.6 mm diameter
e4
Pb-free symbol; Center-Justified
TW
TW = Taiwan; Country of Origin (ISO Abbreviation)
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Rev. 1.0 | 47
Si5380 Rev D Data Sheet
Device Errata
13. Device Errata
Log in or register at www.silabs.com to access the device errata document.
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Rev. 1.0 | 48
Si5380 Rev D Data Sheet
Document Change List
14. Document Change List
14.1 Revision 1.0
July 19, 2016
• Initial release.
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Rev. 1.0 | 49
Table of Contents
1. Feature List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Functional Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.1 Frequency Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.1.1 Si5380 LTE Frequency Configuration . . . . . . . . . . . . . . . . . . . . . 3
3.1.2 Si5380 Configuration for JESD204B Clock Generation . . . . . . . . . . . . . . . 4
3.1.3 DSPLL Loop Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1.4 Fastlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1.5 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1.6 Initialization and Reset . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1.7 Freerun Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1.8 Lock Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1.9 Locked Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1.10 Holdover Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2 External Reference (XA/XB) . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.3 Inputs (IN0, IN1, IN2, IN3/FB_IN) . . . . . . . . . . . . . . . . . . . . . . . 8
3.3.1 Input Configuration and Terminations . . . . . . . . . . . . . . . . . . . . . 9
3.3.2 Manual Input Selection (IN0, IN1, IN2, IN3/FB_IN) . . . . . . . . . . . . . . . . . 9
3.3.3 Automatic Input Switching (IN0, IN1, IN2, IN3/FB_IN) . . . . . . . . . . . . . . . .10
3.3.4 Hitless Input Switching . . . . . . . . . . . . . . . . . . . . . . . . . .10
3.3.5 Ramped Input Switching. . . . . . . . . . . . . . . . . . . . . . . . . .10
3.3.6 Glitchless Input Switching . . . . . . . . . . . . . . . . . . . . . . . . .10
3.3.7 Zero Delay Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
3.4 Fault Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
3.4.1 Input LOS Detection . . . . . . . . . . . . . . . . . . . . . . . . . . .12
3.4.2 XA/XB LOS Detection . . . . . . . . . . . . . . . . . . . . . . . . . .12
3.4.3 OOF Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
3.4.4 Precision OOF Monitor . . . . . . . . . . . . . . . . . . . . . . . . . .13
3.4.5 Fast OOF Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
3.4.6 LOL Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
3.4.7 Interrupt Pin INTRb . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.5 Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.5.1 Output Crosspoint . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.5.2 Output Signal Format. . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.5.3 Output Terminations . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3.5.4 Programmable Common Mode Voltage For Differential Outputs . . . . . . . . . . . .16
3.5.5 LVCMOS Output Terminations . . . . . . . . . . . . . . . . . . . . . . .16
3.5.6 LVCMOS Output Impedance and Drive Strength Selection . . . . . . . . . . . . . .17
3.5.7 LVCMOS Output Signal Swing . . . . . . . . . . . . . . . . . . . . . . .17
3.5.8 LVCMOS Output Polarity . . . . . . . . . . . . . . . . . . . . . . . . .17
3.5.9 Output Enable/Disable . . . . . . . . . . . . . . . . . . . . . . . . . .17
3.5.10 Output Disable During LOL . . . . . . . . . . . . . . . . . . . . . . . .17
3.5.11 Output Disable During XAXB_LOS. . . . . . . . . . . . . . . . . . . . . .17
3.5.12 Output Driver State When Disabled . . . . . . . . . . . . . . . . . . . . .17
Table of Contents 50
3.5.13 Synchronous Enable/Disable Feature . . . . . . . . . . . . . . . . . . . . .17
3.5.14 Output Skew Control (Δt - Δt ) . . . . . . . . . . . . . . . . . . . . . . .18
0
4
3.5.15 Output Divider (R) Synchronization. . . . . . . . . . . . . . . . . . . . . .18
3.6 Power Management . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
3.6.1 Power Down Pin (PDNb) . . . . . . . . . . . . . . . . . . . . . . . . .19
3.7 In-Circuit Programming. . . . . . . . . . . . . . . . . . . . . . . . . . .19
3.8 Serial Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
3.9 Custom Factory Preprogrammed Devices . . . . . . . . . . . . . . . . . . . .19
3.10 Enabling Features and/or Configuration Settings Not Available in ClockBuilder Pro for Factory Pre-
programmed Devices
. . . . . . . . . . . . . . . . . . . . . . . . . . 1.9
4. Register Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . 22
6. Typical Application Diagrams . . . . . . . . . . . . . . . . . . . . . . . . 36
7. Detailed Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 37
8. Typical Operating Characteristics (Phase Noise & Jitter) . . . . . . . . . . . . . . 38
9. Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
10. Package Outline. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
11. PCB Land Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
12. Top Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
13. Device Errata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
14. Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . 49
14.1 Revision 1.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Table of Contents 51
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"Typical" parameters provided can and do vary in different applications. Application examples described herein are for illustrative purposes only. Silicon Laboratories reserves the right to
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