AS5003 Arcadium™ I2C Programmable Oscillator, 10 kHz to 350 MHz
The AS5003 Arcadium™ all-silicon oscillator utilizes proprietary frequency
synthesis and sensor technologies to provide a quartz-free, MEMS-free, low jitter
clock at any output frequency. The device is fully programmable to any frequency
from 10 kHz to 350 MHz with < 0.026 ppb resolution and maintains low jitter
across its operating range. The AS5003 uses on-chip temperature and strain
sensors, and an advanced LC tank architecture to achieve excellent reliabilities
even in high impact shock scenarios.
AS5003’s on-chip power supply filtering provides industry-leading power supply
noise rejection, simplifying the task of generating low jitter clocks in noisy
systems that use switched-mode power supplies. Offered in a variety of industrystandard packages, the AS5003 has a dramatically simplified supply chain that
enables Aeonsemi to ship samples shortly after receipt of order. The AS5003 is
user-configurable with an I2C interface for a wide variety of user specifications,
including frequency, output format, and DCO mode. Default configuration is
factory programmed at time of shipment. It also guarantees 100% electrical
testing of every device before shipment.
KEY FEATURES
• Quartz-free and MEMS-free without
mechanical moving parts
• I2C programmable to any frequency
• Differential: 10 kHz to 350 MHz
• LVCMOS: 10 kHz to 212.5 MHz
• Up to 0.026 ppb frequency tuning resolution
• I2C interface supports 100 kbps, 400 kbps
and 1 Mbps (Fast Mode Plus)
• Low jitter: 350 fs Typ RMS (12 kHz –
20 MHz)
• Compliant to PCIe Gen 1/2/3/4/5 jitter
requirements
• 50 ppm stability (-40 to 105ºC)
• Integrated LDO for on-chip power supply
All Silicon
Oscillator
Flexible
Output Frequency
noise filtering
Flexible
Output Format
• Support continuous 1.8V to 3.3V VDD supply
operation
• LVPECL, LVDS, CML, HCSL, CMOS, and
Dual CMOS output options
• Industrial standard 3.2 x 5, 2.5 x 3.2 mm
Freq / Temp
Comp
package footprints
APPLICATIONS
Control
• 1G/10G/40G/100G Ethernet
• Servers, switches, storage, NICs, search
acceleration
• Test and measurement
I2C
• Clock and data recovery
• FPGA/ASIC clocking
Pin Assignments
Pin #
Descriptions
2
1
SDA = I C Serial Data
2
SCL = I2C Serial Clock
3
GND = Ground
4
CLK+ = Clock output
5
CLK- = Complementary clock output
6
VDD = Power supply
3.2 x 5 mm and 2.5 x 3.2 mm
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This information applies to a product under development. Its characteristics and specifications are subject to change without notice.
Rev. 0.9
AS5003 Datasheet
1. Ordering Guide
The AS5003 Oscillator supports a variety of initial options including frequency, output format, as shown in the chart below.
Configurations are changeable by users via I2C interface upon startup. Samples are available in 2 weeks.
XO Series
Description
5003
I2C Programmable
5003
Total Stability
A
A
A
1
Package
+ 50 ppm
A
-
-
-
-
-
A
3.2 x 5 mm
I
-40 to 85 °C
B
2.5 x 3.2 mm
E
-40 to 105 °C
-
Signal
Format
VDD Range
Coupling
Order
Option
LVPECL
2.5, 3.3 V
DC
A
LVPECL
2.5, 3.3 V
AC
B
LVDS
1.8 V
DC
C
LVDS
2.5, 3.3 V
DC
D
CML
1.8, 2.5, 3.3 V
AC
E
1.8, 2.5, 3.3 V
DC
F
Frequency Code
1.8, 2.5, 3.3 V
DC
G
Mxxxxxxx
1.8, 2.5, 3.3 V
DC
H
1.8, 2.5, 3.3 V
DC
I
1.8, 2.5, 3.3 V
DC
J
HCSL
50
Termination)
HCSL
5
Termination)
CMOS
Dual CMOS
(In-Phase)
Dual CMOS
(Complementary)
Temperature Grade
-
-
A
Output
B
I
2
R
Device Revision
A
Low Power State
B
Default Freq, Output Disabled
Tape and Reel
Package Qty
C
Default Freq, Output Enabled
T
250
R
2500
Bulk
3
Description
FCLK < 1 MHz
xMxxxxxx
1 MHz
xxMxxxxx
10 MHz
xxxMxxxx
100 MHz
FCLK < 10 MHz
FCLK < 100 MHz
FCLK
MHz
An unique startup frequencies can be specified within
the supported range of the selected signal format.
Notes:
1. Total stability includes temp stability, initial accuracy, load pulling, VDD variation, and 10 years aging at 40 °C.
2. Device supports extended industrial temperature range of -40 to 105°C only with VDD = 1.8V (+/- 5%).
3. For example: 156.25 MHz = 156M2500; 25 MHz = 25M00000.
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AS5003 Datasheet
2. Electrical Specifications
Table 2.1 Electrical Specifications
VDD = 1.8 V, 2.5 or 3.3 V ± 5%, TA = –40 to 85 ºC; VDD = 1.8 V ± 5%, TA = –40 to 105 ºC
Parameter
Symbol
Temperature Range
TA
Frequency Range
FCLK
Supply Voltage
VDD
Supply Current
(FCLK = 50 MHz)
IDD
Test Condition/Comment
Min
Typ
Max
Unit
–40
—
105
ºC
LVPECL, LVDS, CML, HCSL
0.01
—
350
MHz
CMOS, Dual CMOS
0.01
—
212.5
MHz
3.47
V
1.71
—
40
50
mA
Ready State
—
1
2
mA
LVPECL (DC-Coupled)
—
70
80
mA
LVPECL (AC-Coupled)
—
60
70
mA
LVDS
—
45
55
mA
HCSL
—
60
70
mA
CML
—
60
70
mA
CMOS
—
40
55
mA
—
50
60
mA
–50
—
50
ppm
Tristate Hi-Z (output disabled)
Dual CMOS
Total Stability1
FSTAB
Frequency stability
Rise/Fall Time
(20% to 80% VPP)
TR/TF
LVPECL/LVDS/CML
—
—
350
ps
CMOS / Dual CMOS
(CL = 5 pF)
—
0.5
1.5
ns
HCSL, FCLK >50 MHz
—
—
550
ps
All formats
45
—
55
%
Duty Cycle
DC
Output Enable (OE)2
VIH
0.7 × VDD
—
—
V
VIL
—
—
0.3 × VDD
V
TD
Output Disable Time,
FCLK >10 MHz
—
—
0.5
µs
TE
Output Enable Time,
FCLK >10 MHz
—
—
0.5
µs
—
—
4
ms
tOSC
Powerup Time
Time from 0.9 × VDD until output
frequency (FCLK) within spec
VOC
Mid-level
VDD – 1.55
—
VDD – 1.25
V
(DC-Coupled)
VO
Swing (diff)
1.4
—
1.85
VPP
LVPECL Output Option3
VO
Swing (diff)
1.4
1.85
VPP
VOC
Mid-level (2.5 V, 3.3 V VDD)
1.125
1.20
1.275
V
Mid-level (1.8 V VDD)
0.795
0.85
0.905
V
Swing (diff)
0.5
0.82
0.96
VPP
LVPECL Output
Option3
(AC-Coupled)
LVDS Output Option4
(DC-Coupled)
VO
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AS5003 Datasheet
Parameter
Symbol
Test Condition/Comment
Min
Typ
Max
Unit
VOH
Output voltage high
695
815
935
mV
VOL
Output voltage low
0
5
10
mV
VOH
Output voltage high
695
820
945
mV
VOL
Output voltage low
0
5
10
mV
CML Output Option4
(AC-Coupled)
VO
Swing (diff)
0.725
0.8
0.89
VPP
CMOS Output Option
VOH
IOH = 8/6/4 mA for 3.3/2.5/1.8V VDD 0.83 × VDD
—
—
V
VOL
IOL = 8/6/4 mA for 3.3/2.5/1.8V VDD
—
0.17 × VDD
V
HCSL Output Option4
(Rterm = 50 Ω; DC-Coupled)
HCSL Output Option5
(Rterm =
5 Ω; DC-Coupled)
—
Notes:
1. Total Stability includes temperature stability, initial accuracy, load pulling, VDD variation, and aging for 10 years at 40 ºC.
2. The TD and TE < 10 ns + 3 * 1/FCLK for all frequencies measured from the end of the I 2C byte write to OE control registers.
3. Rterm = 50 Ω to VDD – 2.0 V (see Figure 4.1).
4. Rterm = 100 Ω differential) see Figure 4.2).
5. Rterm =
5 Ω or 50 Ω to GND see Figure 4.3).
Table 2.2: I2C Characteristics
VDD = 1.8 V, 2.5 or 3.3 V ± 5%, TA = –40 to 85 ºC; VDD = 1.8 V ± 5%, TA = –40 to 105 ºC
Parameter
Frequency Reprogramming Resolution
Frequency Range for Small Frequency
Change (Continuous Glitchless Output)
Settling Time for Small Frequency Change
(DCXO Feature)
Settling Time for Frequency Change
(fUSER_FREQ Register)
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Symbol
Test Condition/Comment
VRES
From center frequency
< ± 970 ppm from center
frequency
Min
Typ
Max
Unit
—
0.026
—
ppb
+970
ppm
8
us
200
us
-970
Rev. 0.9 | 4
AS5003 Datasheet
Table 2.3: Clock Output Phase Jitter and PSRR
VDD = 1.8 V, 2.5 or 3.3 V ± 5%, TA = –40 to 85 ºC; VDD = 1.8 V ± 5%, TA = –40 to 105 ºC
Parameter
Symbol
Test Condition/Comment
Min
Typ
Max
Unit
Phase Jitter (RMS, 12 kHz - 20 MHz)1,2
FCLK ≥ 10 MHz
ϕJ
Differential Formats
—
350
750
fs
CMOS, Dual CMOS
—
350
—
fs
Phase Jitter (RMS, 50 kHz - 20 MHz)
ϕJ
Differential Formats
—
150
250
fs
CMOS, Dual CMOS
—
100
—
fs
100 kHz sine wave
—
-76
—
200 kHz sine wave
—
-75
—
500 kHz sine wave
—
-75
—
1 MHz sine wave
—
-75
—
100 kHz sine wave
—
-83
—
200 kHz sine wave
—
-83
—
500 kHz sine wave
—
-83
—
1 MHz sine wave
—
-82
—
FCLK ≥ 156.25 MHz
Spurs Induced by External Power Supply
Noise, 50 mVpp Ripple.
PSRR
LVDS 156.25 MHz Output
VDD = 1.8 V
Spurs Induced by External Power Supply
Noise, 50 mVpp Ripple.
PSRR
LVDS 156.25 MHz Output
VDD = 2.5 or 3.3 V
dBc
dBc
Note:
1. Applies to output frequency: 50, 100, 156.25, 212.5, 350 MHz
2. Guaranteed by characterization. Jitter inclusive of any spurs
Figure 2.1: Phase Noise at 156.25 MHz
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AS5003 Datasheet
Table 2.4: Environmental Compliance and Package Information
Parameter
Test Condition
Moisture Sensitivity Level
1
Note:
For additional product information not listed in the data sheet (e.g. RoHS Certifications, MSDS data, qualification data,
REACH Declarations, ECCN codes, etc.), contact aeonsemi.com/contact-us/
Table 2.5: Thermal Conditions
Package
Parameter
Symbol
Test Condition
Value
Unit
Thermal Resistance Junction to Ambient
ΘJA
Still Air
105
ºC/W
Thermal Resistance Junction to Board
ΘJB
Still Air
81
ºC/W
Max Junction Temperature
TJ
Still Air
125
ºC
Thermal Resistance Junction to Ambient
ΘJA
Still Air
108
ºC/W
Thermal Resistance Junction to Board
ΘJB
Still Air
84
ºC/W
Max Junction Temperature
TJ
Still Air
125
ºC
3.2 x 5 mm,
6-pin DFN
2.5 x 3.2 mm,
6-pin DFN
Table 2.6: Absolute Maximum Ratings1
Parameter
Symbol
Rating
Unit
TAMAX
105
ºC
TS
-55 to 125
ºC
Supply Voltage
VDD
-0.5 to 3.8
V
Input Voltage
VIN
-0.5 to VDD + 0.3
V
ESD HBM (JESD22-A114)
HBM
4.0
kV
Solder Temperature3
TPEAK
260
ºC
Solder Time at TPEAK3
TP
20 - 40
sec
Maximum Operating Temperature2
Storage Temperature
Notes:
1. Stresses beyond those listed in this table may cause permanent damage to the device. Functional operation specification
compliance is not implied at these conditions. Exposure to maximum rating conditions for extended periods may affect device
reliability.
2. For VDD = 1.8V only; otherwise 85ºC.
3. The device is compliant with JEDEC J-STD-020.
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AS5003 Datasheet
3. CMOS Buffer and Output Terminations
Dual CMOS output format ordering options support either complementary or in-phase signals for two identical frequency outputs. This
feature enables replacement of multiple XOs with a single AS5003 device.
Figure 3.1: Integrated 1:2 CMOS Buffer Supports In-Phase or Complementary Outputs
AS50xx
AS50xx
VDD
VDD
CLK+
CLK
CLK-
CMOS
Receiver
NC
CMOS
Receiver
Single CMOS Termination
Dual CMOS Termination
Figure 3.2: CMOS Output Terminations
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AS5003 Datasheet
4. Recommended Output Terminations
The output drivers support AC-coupled or DC-coupled terminations as shown in figures below.
AS50xx
AS50xx
VDD (3.3V, 2.5V)
VDD (3.3V, 2.5V)
R1
CLK+
0.1 µF
CLK-
0.1 µF
R1
R1
R1
R2
R2
CLK+
CLK-
R2
R2
LVPECL
Receiver
AC-Coupled LVPECL – Thevenin Termination
LVPECL
Receiver
DC-Coupled LVPECL – 50 Ω w/ VTT Bias
AS50xx
AS50xx
VDD (3.3V, 2.5V)
VDD (3.3V, 2.5V)
CLK+
VDD
CLK-
VDD (3.3V, 2.5V)
VDD (3.3V, 2.5V)
R1
CLK+
0.1 µF
VDD
R2
CLK-
0.1 µF
R1
R2
LVPECL
Receiver
LVPECL
Receiver
DC-Coupled LVPECL – Thevenin Termination
AC-Coupled LVPECL – 50 Ω w/ VTT Bias
Termination Resistor Values
VDD
3.3 V
1 7
R1
8 5
R2
2.5 V
50
6 5
Figure 4.1: LVPECL Output Terminations
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AS5003 Datasheet
DC-Coupled LVDS
AC-Coupled CML
Figure 4.2: LVDS / CML Output Terminations
AS50xx
AS50xx
VDD
VDD
CLK+
CLK+
CLK-
CLKHCSL
Receiver
HCSL
Receiver
Source Terminated HCSL
Destination Terminated HCSL
Figure 4.3: HCSL Output Terminations
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AS5003 Datasheet
5. Configuring via I2C Interface
5.1 I2C Serial Interface
The I2C interface on the AS5003 is fully compatible with the “UM10 0 I2C-bus specification and user manual, Rev. 6 standard, as described in Table 5.1.
Table 5.1: I2C compatibility
I2C
Speed
Compliance
Notes
Standard
100 kHz
Compliant
N/A
Fast
400 kHz
Compatible
SDA failing edge can be faster than 20 ns depending on loading
Fast+
1 MHz
Compatible
SDA falling edge can be faster than 20 ns depending on loading.
April 01 ”
SDA max pull down current is 6 mA.
5.2 I2C Register Write and Read Protocol
AS5003 implements an 8-bit I2C address space with 256 addressable byte register locations. Certain device register and bits are
reserved, and they must not be changed from their default reset state.
In an I2C bus system, the AS5003 acts as a slave device connected to the I 2C serial interface bus. It is accessed via a 7-bit factory
programmed (per user specification) slave address. Allowed values of this device address are in the range from 16 to 119. Both write
and read register transactions with register address autoincrement are enabled as shown in Figure 5.1.
I2C Register Wr
S
DevAddr
0
Register write data
A
Addr
W
A
A:
D0
A
A
D1
A
DN-1
A+1
...
A+N-1
I2C Register Rd
S
DevAddr
0
A P/Sr
Write to address
Register read data
A
Addr
W
A Sr
A:
S .. START
P .. STOP
Sr .. RESTART
DevAddr
1
R
A
D0
A
A
D1
A
DN-1
A+1
...
A+N-1
A .. ACK
N .. NACK
R .. Read
W .. Write
N P/Sr
Read from address
Figure 5.1: I2C write and read transactions
Write register transaction is an I2C write transaction with an 8-bit register address data byte stream. It is followed by one or more
register data bytes. Read register sequence starts after a write transaction to set the read register address. It is followed by the I2C
read transaction to read one or more data bytes.
The register address autoincrement is enabled upon power up. It is incremented till a maximum address 0xFF of the I2C register space
is reached.
The register address autoincrement is disabled by writing register bI2C_INC_DIS=1 and re-enabled again by writing bI2C_INC_DIS=0.
During this process, all bytes in the I2C transactions are written to or read from a set address. Having the register autoincrement
disabled is required for a DCXO streaming mode.
Data and address bytes appear on the SDA bus with the most significant bit (MSB) first per I2C standard. During I2C transactions, SCL
clock bus is never stalled by the device.
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AS5003 Datasheet
5.3 Device Operation
After an initial power up sequence, the device operates in either Ready state or an Active state depending on customization in factory.
The Ready state is a power down standby state when majority of internal circuitries are powered down. The Active state is the device
active mode with all internal circuitries powered up. Writing to register bUSYS_CTRL can move the device between Ready state and
Active state.
The following three power up options are available for factory configuration:
1.
Ready state: The device is in the power down standby mode. Writing transaction to register bUSYS_CTRL is required to
enable the device and enable the Active state.
Active state with bODIV_CTRL=0: The device generates frequency internally, but output is disabled. Writing transaction to
register bODIV_CTRL is required to enable output driver to propagate output frequency.
Active state with bODIV_CTRL=1: The device is fully functional, and output is enabled. I2C intervention is not necessary.
2.
3.
In the state 1 and 2 above, user can write to I2C to change drive mode or central frequency from the factory set values prior to enabling
the device output or before moving to Active state.
5.4 Changing Frequency and Output Driver Mode
After startup, the device is at the factory set frequency, output driver mode, and device state. The device is ready to be controlled by I2C
register writes. All register writes can take immediate effect, except fUSER_FREQ and bDRV_MODE registers which require a follow
on Apply command. User frequency register, “fUSER_FREQ”, is a -byte big endian register representing frequency as a binary32
IEEE 754- 008 standard number, in [Hz] units User driver mode register, “bDRV_MODE” is a single byte number representing driver
mode described in Table 5.19.
Changing frequency and driver mode requires two steps:
1.
Writing fUSER_FREQ and/or bDRV_MODE registers with the new desired central frequency and/or driver mode. Only the
changing register needs to be written. Writing order in bytes is not essential. Writing these registers only records the new
values, but does not invoke any internal processing.
Writing bUSYS_CTRL register with one of four Apply* commands. Once the Apply* command is accepted, the device uses the
fUSER_FREQ and bDRV_MODE register values and invokes internal central frequency and/or driver mode.
2.
Changing frequency can be completed by either disabling the output driver or keeping the output drive enabled. This is determined by
applying different Apply* commands. The bUSYS_CTRL values and descriptions are shown in Table 5.2.
Table 5.2: System control register bUSYS_CTRL
Value
Mnemonic
Description
0
UsysNop
No operation
--
1
UsysReady
Ready standby power down state
--
2
UsysActive
Active state
--
3
No operation
--
4
UsysRstSys
Invoke system reset restart
--
5
UsysRstPor
Invoke power-on reset restart
--
6
Do not use
--
7
Do not use
--
UsysApply
Apply: Disable output if active, update only
changed frequency/driver mode
Check/Set
UsysApplyForce
Apply force: Disable output if active, force
frequency/driver mode update
Check/Set
UsysApplyAct
Apply active: Keep output running if active, update
only changed frequency/driver mode
Check/Set
UsysApplyActForce
Apply active force: Keep output running if active,
force frequency/driver mode update
Check/Set
UsysRefresh
Refresh: Refresh fUSER_FREQ and bDRV_MODE
register values to reflect the actual current device
frequency and driver mode settings
Check/Set
8
9
10
11
12
Others
Do not use
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stat_busy
--
Rev. 0.9 | 11
AS5003 Datasheet
Writing to “bUSYS_CTRL” register generates an acceptance request When this command is accepted, the “bUSYS_CTRL” register is
cleared. If a read from “bUSYS_CTRL” returns a non-zero value, it means that the writing command is still waiting to be accepted. A
command acceptance happens in less than 5 us from the finishing of writing to the “bUSYS_CTRL” register An accepted command
can be either processed or ignored.
Commands other than “Apply*” and “Refresh” are always processed after the acceptance It is possible to interrupt any “Apply*” or
“Refresh” command under processing A processing time depends on the command and its current state of the device, in most cases it
is 1 ~ 5 us, but can be up to 160 us when the command is generated in the middle of the frequency change.
“Apply*” and “Refresh” commands are only processed when “bUSYS_STATS stat_busy” = 0 When “bUSYS_STATS stat_busy” = 1,
although new “Apply*” and “Refresh” commands are accepted, they are ignored The “bUSYS_STATS stat_busy” = 1 status bit is the
beginning of internal processing The “bUSYS_STATS stat_busy” = 0 occurs after this internal processing finishes. Changing frequency
and output driver must be completed before invoking a new command.
Issuing a “Refresh” command reset the values of registers to match the actual state of the device During a normal operation, the
device keeps the values of fUSER_FREQ and bDRV_MODE synchronized with the internal state of the device. Reading these registers
represent the actual frequency and output driver mode. However, the values could be different if writing occurs before applying the
“Apply*” or “Refresh” command If the “Apply*” command is not applied, then the registers value are the previous written values. Thus,
issuing the “Refresh” command is necessary.
“fUSER_FREQ” and “bUSYS_STAT” registers are located back to back in I 2C address space. As a result, the most used operation is
done in a single I2C transaction as shown in Figure 5.2. This example shows changing the frequency to a 70 MHz, which corresponds a
32-bit floating point number, 0x c8583b0 in [Hz] It is followed by a “Apply” command to invoke the internal frequency update, and
assumed that the I2C register address autoincrement is enabled, which is a default.
70.0 MHz frequency change
S
DevAddr
0
A
0x55
A
0x4c
70.0 MHz
Apply
fUSER_FREQ
bUSYS_CTRL
0x85
A
A
0x83
A
0xb0
A
0x08
A P/Sr
W
Figure 5.2: Frequency change I2C transaction
5.5 System Status
“bUSYS_STAT” is a read only system status register It is readable any time and it reflects the current device status. All possible values
of the register are listed in Table 5.3.
Table 5.3: System status bUSYS_STAT register values
stat_busy
--
--
stat_trans
stat_rst
stat_tune
stat_actifve
stat_ready
bUSYS_STAT
[7]
[6]
[5]
[4]
[3]
[2]
[1]
[0]
0
0
0
0
0
0
0
0
Start up
v
0
0
0
0
0
0
1
Ready state
v
0
0
0
0
0
1
0
Active state
v
0
0
0
0
1
1
0
Active state, tuning to new frequency
v
0
0
1
0
0
0
1
Ready Active transition
v
0
0
1
0
0
1
0
Active Ready transition
0
0
0
1
1
0
0
0
Reset processing, shutting down
0
0
0
0
1
0
0
0
Reset accepted
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Description
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AS5003 Datasheet
stat_busy bit [7] value v denotes value 0 or 1. The bit is 1 at the beginning of Apply* and Refresh commands internal processing and is
0 when the processing is done.
5.6 Output Drive Control
The output driver is powered up only in an Active state. CLKP and CLKM output signals are enabled or disabled by OE control register
bits, “bUDRV_CTRL.udrv_oe_stop” and “bODIV_CTRL.odiv_oe_ena”. The simplified control flow of output driver is shown in Figure
5.3.
Active
bUSYS_CTRL
on
VDD
CLKM
Output
Divider
Driver
CLKP
udrv_oe_stop
bDRV_CFG
bUDRV_CTRL
bDRV_MODE
odiv_oe_ena
bODIV_CTRL
Figure 5.3: Driver control flow
Putting system to Ready state or disabling the driver with “bDRV_MODE” = 0 to issue one of the “Apply*” commands power down the
output driver.
5.7 Center Frequency Control
Changing “fUSER_FREQ” register value controls the center frequency. The step does not apply to the DCXO feature.
Frequency change request shown in Figure 5.4 and Figure 5.5 marks the time when a “Apply*” command is written to a
“bUSYS_CTRL” register which corresponds with the write of the last data bit to this “bUSYS_CTRL” register.
Figure 5.4 shows a timing of frequency change by using “Apply” command when a “fUSER_FREQ” register value is different from the
current frequency; or using “ApplyForce” command with the output disabled during the frequency change.
fCURR
fNEW
Frequency
change
request
Steady
OUT Off
Tune to fUSER_FREQ
OUT On
tDRVOFF
tTUNE
tDRVON
5 .. 25 μs