1.2 GHz Clock Fanout Buffer
with Output Dividers and Delay
AD9508-EP
Enhanced Product
FEATURES
GENERAL DESCRIPTION
1.2 GHz differential clock inputs/outputs
10-bit programmable dividers, 1 to 1024, all integers
Up to 4 differential outputs or 8 CMOS outputs
Pin strapping mode for hardwired programming at power-up
<115 fs rms broadband random jitter (see Figure 25)
Additive output jitter: 41 fs rms typical (12 kHz to 20 MHz)
Excellent output-to-output isolation
Automatic synchronization of all outputs
Single 2.5 V power supply
Internal low dropout (LDO) voltage regulator for enhanced
power supply immunity
Phase offset select for output-to-output coarse delay adjust
3 programmable output logic levels: LVDS, HSTL, and CMOS
Serial control port (SPI/I2C) or pin programmable mode
Space-saving 24-lead LFCSP
The AD9508-EP provides clock fanout capability in a design
that emphasizes low jitter to maximize system performance. The
AD9508-EP benefits applications such as clocking data
converters with demanding phase noise and low jitter
requirements.
ENHANCED PRODUCT FEATURES
The device can also be pin programmed for various fixed
configurations at power-up without the need for SPI or I²C
programming.
The AD9508-EP has four independent differential clock outputs,
each with various types of logic levels available. Available logic
types are LVDS (1.2 GHz), HSTL (1.2 GHz), and 1.8 V CMOS
(250 MHz). In 1.8 V CMOS output mode, the differential output
becomes two CMOS single-ended signals. The CMOS outputs
are 1.8 V logic levels.
Each output has a programmable divider that can be bypassed or
set to divide by any integer up to 1024. In addition, the AD9508-EP
supports coarse output phase adjustment between the outputs.
Supports defense and aerospace applications (AQEC standard)
Extended temperature range: −55°C to +105°C
Controlled manufacturing baseline
One assembly/test site
One fabrication site
Enhanced product change notification
Qualification data available on request
The AD9508-EP is available in a 24-lead LFCSP and operates
from a single 2.5 V power supply. The temperature range is
−55°C to +105°C.
Additional application and technical information can be found
in the AD9508 data sheet.
APPLICATIONS
Low jitter, low phase noise clock distribution
Clocking high speed ADCs, DACs, DDSs, DDCs, DUCs, MxFEs
High performance wireless transceivers
High performance instrumentation
Broadband infrastructure
FUNCTIONAL BLOCK DIAGRAM
DIV/Φ
CLK
DIV/Φ
CLK
DIV/Φ
SCLK/SCL/S0
SDIO/SDA/S1
SDO/S3
CS/S2
DIV/Φ
CONTROL
INTERFACE
SPI/I2C/PINS
PIN CONTROL
RESET
SYNC
OUT0
OUT0
OUT1
OUT1
OUT2
OUT2
OUT3
OUT3
11367-001
AD9508-EP
Figure 1.
Rev. B
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Tel: 781.329.4700 ©2013–2014 Analog Devices, Inc. All rights reserved.
Technical Support
www.analog.com
AD9508-EP
Enhanced Product
TABLE OF CONTENTS
Features .............................................................................................. 1
Serial Port Specifications—I2C Mode .........................................7
Enhanced Product Features ............................................................ 1
External Resistor Values for Pin Strapping Mode .....................7
Applications ....................................................................................... 1
Clock Output Additive Phase Noise ...........................................8
General Description ......................................................................... 1
Clock Output Additive Time Jitter..............................................9
Functional Block Diagram .............................................................. 1
Absolute Maximum Ratings ......................................................... 10
Revision History ............................................................................... 2
Thermal Characteristics ............................................................ 10
Specifications..................................................................................... 3
ESD Caution................................................................................ 10
Power Supply Current and Temperature Conditions .............. 3
Pin Configuration and Function Descriptions........................... 11
Clock Input and Output DC Specifications .............................. 3
Typical Performance Characteristics ........................................... 13
Output Driver Timing Characteristics ...................................... 5
Outline Dimensions ....................................................................... 19
Logic Inputs ................................................................................... 5
Ordering Guide .......................................................................... 19
Serial Port Specifications—SPI Mode ........................................ 6
REVISION HISTORY
10/14—Rev. A to Rev. B
Changed Input Resistance (Differential) to Input Resistance
(Single-Ended), Table 2 .................................................................... 3
10/13—Rev. 0 to Rev. A
Changes to Ordering Guide .......................................................... 19
7/13—Revision 0: Initial Version
Rev. B | Page 2 of 19
Enhanced Product
AD9508-EP
SPECIFICATIONS
Typical values are given for VS = 2.5 V and TA = 25°C; minimum and maximum values are given over the full supply voltage range
(VDD = 2.5 V ± 5%) and temperature range (TA = −55°C to +105°C); input slew rate > 1 V/ns, unless otherwise noted.
POWER SUPPLY CURRENT AND TEMPERATURE CONDITIONS
Table 1.
Parameter
SUPPLY VOLTAGE
CURRENT CONSUMPTION
LVDS Configuration
Min
2.375
HSTL Configuration
CMOS Configuration
Full Power-Down
TEMPERATURE
Ambient Temperature Range, TA
Junction Temperature, TJ
−55
Typ
2.5
Max
2.625
Unit
V
Test Conditions/Comments
132
148
mA
96
108
mA
156
175
mA
121
136
mA
86
96
mA
142
159
mA
118
132
mA
76
85
mA
Input clock at 1200 MHz, differential mode;
all LVDS output drivers at 1200 MHz
Input clock at 800 MHz, differential mode;
all LVDS output drivers at 200 MHz
Input clock at 1200 MHz, differential mode;
all HSTL output drivers at 1200 MHz
Input clock at 491.52 MHz, differential mode;
all HSTL output drivers at 491.52 MHz
Input clock at 122.88 MHz, differential mode;
all HSTL output drivers at 122.88 MHz
Input clock at 1200 MHz, differential mode;
all CMOS output drivers at 200 MHz, CLOAD = 10 pF
Input clock at 800 MHz, differential mode;
all CMOS output drivers at 200 MHz, CLOAD = 10 pF
Input clock at 100 MHz, differential mode;
all CMOS output drivers at 100 MHz, CLOAD = 10 pF
4.6
8
mA
+25
+105
135
°C
°C
Typ
Max
Unit
Test Conditions/Comments
1200
2200
MHz
mV p-p
1.15
V
Differential input
As measured with a differential probe;
jitter performance improves with higher
slew rates (greater voltage swing)
Input pins are internally self biased,
which enables ac coupling
1.67
mV
V
Junction temperatures above 115°C can degrade
performance, but no damage should occur unless
the absolute temperature is exceeded
CLOCK INPUT AND OUTPUT DC SPECIFICATIONS
Table 2.
Parameter
CLOCK INPUTS (DIFFERENTIAL MODE)
Input Frequency
Input Sensitivity
Input Common-Mode Voltage
Input Voltage Offset
DC-Coupled Input Common-Mode
Range
Pulse Width Low
Pulse Width High
Input Resistance (Single-Ended)
Input Capacitance
Input Bias Current (Each Pin)
Symbol
Min
0
360
VICM
0.95
VCMR
0.58
1.05
30
417
417
5.0
CIN
100
7
2
9
400
Rev. B | Page 3 of 19
ps
ps
kΩ
pF
µA
Allowable common-mode voltage
range when dc-coupled
Full input swing
AD9508-EP
Parameter
CMOS CLOCK MODE (SINGLE-ENDED)
Input Frequency
Input Voltage High
Input Voltage Low
Input Current High
Input Current Low
Input Capacitance
LVDS CLOCK OUTPUTS
Output Frequency
Differential Output Voltage
Enhanced Product
Symbol
Min
Typ
VIH
VIL
IINH
IINL
CIN
VDD − 0.4
Max
Unit
250
MHz
V
V
µA
µA
pF
0.4
1
−142
2
Termination = 100 Ω differential
(OUTx, OUTx)
VOD
Delta VOD
ΔVOD
Offset Voltage
Delta VOS
VOS
ΔVOS
Short-Circuit Current
LVDS Duty Cycle
ISA, ISB
247
1.125
1200
454
MHz
mV
50
mV
1.18
1.375
50
V
mV
13.6
24
55
61
mA
%
%
1200
978
971
55
60
MHz
mV
mV
%
%
250
MHz
0.1
V
V
0.6
V
V
0.35
55
V
V
%
375
45
39
HSTL CLOCK OUTPUTS
Output Frequency
Differential Output Voltage
Common-Mode Output Voltage
HSTL Duty Cycle
VO
VOCM
859
905
45
40
925
940
CMOS CLOCK OUTPUTS
Output Frequency
Output Voltage
1 mA Load
High
Low
10 mA Load
High
Low
10 mA Load (2 × CMOS Mode)
High
Low
CMOS Duty Cycle
Test Conditions/Comments
VOH
VOL
1.7
VOH
VOL
1.2
VOH
VOL
1.45
45
Rev. B | Page 4 of 19
VOH − VOL measurement across a
differential pair at the default
amplitude setting with output driver
not toggling; see Figure 6 for variation
over frequency
Absolute value of the difference
between VOD when the normal output
is high vs. when the complementary
output is high
(VOH + VOL)/2 across a differential pair
Absolute value of the difference
between VOS when the normal output
is high vs. when the complementary
output is high
Each pin (output shorted to GND)
Up to 750 MHz input
750 MHz to 1200 MHz input
Termination = 100 Ω differential;
default amplitude setting
VOH − VOL with output driver static
(VOH + VOL)/2 with output driver static
Up to 750 MHz input
750 MHz to 1200 MHz input
Single-ended; termination = open;
OUTx and OUTx in phase
10 pF load per output; see Figure 14
for output swing vs. frequency
Up to 250 MHz
Enhanced Product
AD9508-EP
OUTPUT DRIVER TIMING CHARACTERISTICS
Table 3.
Parameter
LVDS OUTPUTS
Output Rise/Fall Time
Propagation Delay, Clock to LVDS Output
Temperature Coefficient
Output Skew, All LVDS Outputs1
On the Same Part
Across Multiple Parts
Symbol
Min
Typ
Max
Unit
tR , tF
tPD
1.52
152
2.01
2.8
192
2.49
ps
ns
ps/°C
48
781
ps
ps
154
2.56
ps
ns
ps/°C
59
825
ps
ps
1.47
3.14
ns
ns
ps/°C
112
965
ps
ps
77
119
ps
LVDS Outputs and CMOS Outputs
497
708
ps
HSTL Outputs and CMOS Outputs
424
628
ps
HSTL OUTPUTS
Output Rise/Fall Time
Propagation Delay, Clock to HSTL Output
Temperature Coefficient
Output Skew, All HSTL Outputs1
On the Same Part
Across Multiple Parts
CMOS OUTPUTS
Output Rise/Fall Time
Propagation Delay, Clock to CMOS Output
Temperature Coefficient
Output Skew, All CMOS Outputs1
On the Same Part
Across Multiple Parts
tR , tF
tPD
tR , tF
tPD
118
2.05
2.9
1.55
1.18
2.56
3.3
1.98
OUTPUT LOGIC SKEW1
LVDS Outputs and HSTL Outputs
1
Test Conditions/Comments
Termination = 100 Ω differential, 1 × LVDS
20% to 80% measured differentially
Assumes same temperature and supply;
takes into account worst-case propagation
delay delta due to worst-case process
variation
Termination = 100 Ω differential, 1 × HSTL
20% to 80% measured differentially
Assumes same temperature and supply;
takes into account worst-case propagation
delay delta due to worst-case process
variation
20% to 80%; CLOAD = 10 pF
10 pF load
Assumes same temperature and supply;
takes into account worst-case propagation
delay delta due to worst-case process
variation
CMOS load = 10 pF and LVDS load = 100 Ω
Outputs on the same device; assumes
worst-case output combination
Outputs on the same device; assumes
worst-case output combination
Outputs on the same device; assumes
worst-case output combination
Output skew is the difference between any two similar delay paths while operating at the same voltage and temperature.
LOGIC INPUTS
Table 4.
Parameter
LOGIC INPUTS (RESET, SYNC, IN_SEL)
Input Voltage High
Input Voltage Low
Input Current
Input Capacitance
Symbol
Min
VIH
VIL
IINH, IINL
CIN
1.7
Typ
−300
Max
Unit
Test Conditions/Comments
0.7
+100
V
V
µA
pF
2.5 V supply voltage operation
2.5 V supply voltage operation
2
Rev. B | Page 5 of 19
AD9508-EP
Enhanced Product
SERIAL PORT SPECIFICATIONS—SPI MODE
Table 5.
Parameter
CS
Input Voltage
Logic 1
Logic 0
Input Current
Logic 1
Logic 0
Input Capacitance
SCLK
Input Voltage
Logic 1
Logic 0
Input Current
Logic 1
Logic 0
Input Capacitance
SDIO (INPUT)
Input Voltage
Logic 1
Logic 0
Input Current
Logic 1
Logic 0
Input Capacitance
SDIO (OUTPUT)
Output Voltage
Logic 1
Logic 0
SDO
Output Voltage
Logic 1
Logic 0
TIMING
SCLK
Clock Rate, 1/tCLK
Pulse Width High, tHIGH
Pulse Width Low, tLOW
SDIO to SCLK Setup, tDS
SCLK to SDIO Hold, tDH
SCLK to Valid SDIO and SDO, tDV
CS to SCLK Setup (tS)
CS to SCLK Hold (tC)
CS Minimum Pulse Width High
Min
Typ
Max
Unit
0.4
V
V
VDD − 0.4
−4
−85
2
Test Conditions/Comments
CS has an internal 35 kΩ pull-up resistor
µA
µA
pF
SCLK has an internal 35 kΩ pull-down resistor
VDD − 0.4
0.4
70
13
2
V
V
µA
µA
pF
VDD − 0.4
0.4
−1
−1
2
V
V
µA
µA
pF
1 mA load current
VDD − 0.4
0.4
V
V
0.4
V
V
1 mA load current
VDD − 0.4
30
4.6
3.5
2.9
0
15
3.4
0
3.4
Rev. B | Page 6 of 19
MHz
ns
ns
ns
ns
ns
ns
ns
ns
Enhanced Product
AD9508-EP
SERIAL PORT SPECIFICATIONS—I2C MODE
Table 6.
Parameter
SDA, SCL (INPUTS)
Min
Input Voltage
Logic 1
Logic 0
Input Current
Hysteresis of Schmitt Trigger Inputs
SDA (OUTPUT)
Output Logic 0 Voltage
Output Fall Time from VIH (MIN) to VIL (MAX)
TIMING
SCL Clock Rate
Bus-Free Time Between a Stop and Start
Condition, tBUF
Repeated Start Condition Setup Time, tSU; STA
Repeated Start Condition Hold Time, tHD; STA
Stop Condition Setup Time, tSU; STO
Low Period of the SCL Clock, tLOW
High Period of the SCL Clock, tHIGH
Data Setup Time, tSU; DAT
Data Hold Time, tHD; DAT
Typ
Max
Unit
0.4
0
V
V
µA
mV
0.4
250
V
ns
400
kHz
µs
0.6
0.6
µs
µs
0.6
1.3
0.6
100
0
µs
µs
µs
ns
µs
VDD − 0.4
−40
150
1.3
0.9
Test Conditions/Comments
SDA and SCL have internal 80 kΩ
pull-up resistors
VIN = 10% to 90%
IO = 3 mA
10 pF ≤ Cb ≤ 400 pF
After this period, the first clock
pulse is generated
EXTERNAL RESISTOR VALUES FOR PIN STRAPPING MODE
Table 7.
Parameter
EXTERNAL RESISTORS
Voltage Level 0
Voltage Level 1
Voltage Level 2
Voltage Level 3
Voltage Level 4
Voltage Level 5
Voltage Level 6
Voltage Level 7
Resistor Polarity
Pull down to ground
Pull down to ground
Pull down to ground
Pull down to ground
Pull up to VDD
Pull up to VDD
Pull up to VDD
Pull up to VDD
Min
Typ
820
1.8
3.9
8.2
820
1.8
3.9
8.2
Rev. B | Page 7 of 19
Max
Unit
Ω
kΩ
kΩ
kΩ
Ω
kΩ
kΩ
kΩ
Test Conditions/Comments
Using 10% tolerance resistor
AD9508-EP
Enhanced Product
CLOCK OUTPUT ADDITIVE PHASE NOISE
Table 8.
Parameter
ADDITIVE PHASE NOISE, CLOCK TO HSTL OR LVDS
CLK = 1200 MHz, OUTx = 1200 MHz
Divide Ratio = 1
10 Hz Offset
100 Hz Offset
1 kHz Offset
10 kHz Offset
100 kHz Offset
1 MHz Offset
10 MHz Offset
100 MHz Offset
ADDITIVE PHASE NOISE, CLOCK TO HSTL, LVDS, OR CMOS
CLK = 625 MHz, OUTx = 125 MHz
Divide Ratio = 5
10 Hz Offset
100 Hz Offset
1 kHz Offset
10 kHz Offset
100 kHz Offset
1 MHz Offset
10 MHz Offset
20 MHz Offset
ADDITIVE PHASE NOISE, CLOCK TO HSTL OR LVDS
CLK = 491.52 MHz, OUTx = 491.52 MHz
Divide Ratio = 1
10 Hz Offset
100 Hz Offset
1 kHz Offset
10 kHz Offset
100 kHz Offset
1 MHz Offset
10 MHz Offset
20 MHz Offset
Min
Typ
Max
Unit
Test Conditions/Comments
Input slew rate > 1 V/ns
−90
−101
−110
−117
−135
−144
−149
−150
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
Input slew rate > 1 V/ns
−114
−125
−133
−141
−159
−162
−163
−163
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
Input slew rate > 1 V/ns
−100
−111
−120
−127
−146
−153
−153
−153
Rev. B | Page 8 of 19
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
Enhanced Product
AD9508-EP
CLOCK OUTPUT ADDITIVE TIME JITTER
Table 9.
Parameter
LVDS OUTPUT ADDITIVE TIME JITTER
CLK = 622.08 MHz, Outputs = 622.08 MHz
CLK = 622.08 MHz, Outputs = 155.52 MHz
CLK = 125 MHz, Outputs = 125 MHz
CLK = 400 MHz, Outputs = 50 MHz
HSTL OUTPUT ADDITIVE TIME JITTER
CLK = 622.08 MHz, Outputs = 622.08 MHz
CLK = 622.08 MHz, Outputs = 155.52 MHz
CMOS OUTPUT ADDITIVE TIME JITTER
CLK = 100 MHz, Outputs = 100 MHz
Min
Typ
Max
Unit
Test Conditions/Comments
41
70
69
93
144
142
fs rms
fs rms
fs rms
fs rms
fs rms
fs rms
BW = 12 kHz to 20 MHz
BW = 20 kHz to 80 MHz
BW = 50 kHz to 80 MHz
BW = 12 kHz to 20 MHz
BW = 20 kHz to 80 MHz
BW = 50 kHz to 80 MHz
105
209
206
184
fs rms
fs rms
fs rms
fs rms
BW = 12 kHz to 20 MHz
BW = 20 kHz to 80 MHz
BW = 50 kHz to 80 MHz
BW = 12 kHz to 20 MHz
41
56
72
70
76
87
158
156
fs rms
fs rms
fs rms
fs rms
fs rms
fs rms
fs rms
fs rms
BW = 12 kHz to 20 MHz
BW = 100 Hz to 20 MHz
BW = 20 kHz to 80 MHz
BW = 50 kHz to 80 MHz
BW = 12 kHz to 20 MHz
BW = 100 Hz to 20 MHz
BW = 20 kHz to 80 MHz
BW = 50 kHz to 80 MHz
91
fs rms
BW = 12 kHz to 20 MHz
Rev. B | Page 9 of 19
AD9508-EP
Enhanced Product
ABSOLUTE MAXIMUM RATINGS
THERMAL CHARACTERISTICS
Table 10.
Parameter
Supply Voltage (VDD)
Maximum Digital Input Voltage
CLK and CLK
Maximum Digital Output Voltage
Storage Temperature Range
Operating Temperature Range
Lead Temperature (Soldering, 10 sec)
Junction Temperature
Rating
3.6 V
−0.5 V to VDD + 0.5 V
−0.5 V to VDD + 0.5 V
−0.5 V to VDD + 0.5 V
−65°C to +150°C
−55°C to +105°C
300°C
150°C
Thermal characteristics are established using JEDEC JESD51-7
and JEDEC JESD51-5 2S2P test boards.
Table 11. Thermal Characteristics, 24-Lead LFCSP
Symbol
θJA
θJMA
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
θJMA
The following equation determines the junction temperature on
the application PCB:
ΨJT
TJ = TCASE + (ΨJT × PD)
θJB
θJC
Thermal Characteristic1
Junction-to-ambient thermal resistance per JEDEC JESD51-2 (still air)
Junction-to-ambient thermal resistance, 1.0 m/sec airflow per JEDEC
JESD51-6 (moving air)
Junction-to-ambient thermal resistance, 2.5 m/sec airflow per JEDEC
JESD51-6 (moving air)
Junction-to-board thermal resistance
per JEDEC JESD51-8 (still air)
Junction-to-case thermal resistance
(die-to-heat sink) per MIL-STD-883,
Method 1012.1
Junction-to-top-of-package characterization parameter per JEDEC
JESD51-2 (still air)
Unit
°C/W
40
°C/W
38.5
°C/W
16.2
°C/W
7.1
°C/W
0.33
°C/W
The exposed pad on the bottom of the package must be soldered to ground
(VSS) to achieve the specified thermal performance.
2
Results are from simulations. The PCB is a JEDEC multilayer type. Thermal
performance for actual applications requires careful inspection of the conditions
in the application to determine whether they are similar to those assumed
in these calculations.
1
where:
TJ is the junction temperature (°C).
TCASE is the case temperature (°C) measured by the customer at
the top center of the package.
ΨJT is the value indicated in Table 11.
PD is the power dissipation.
Value2
43.5
ESD CAUTION
Values of θJA are provided for package comparison and PCB
design considerations. θJA can be used for a first-order
approximation of TJ by the following equation:
TJ = TA + (θJA × PD)
where TA is the ambient temperature (°C).
Values of θJC are provided for package comparison and PCB
design considerations when an external heat sink is required.
Values of θJB are provided for package comparison and PCB
design considerations.
Rev. B | Page 10 of 19
Enhanced Product
AD9508-EP
19 SCLK/SCL/S0
21 CLK
20 SYNC
22 CLK
24 SDIO/SDA/S1
23 IN_SEL
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
18 RESET
CS/S2 1
OUT0 2
17 OUT3
16 OUT3
AD9508-EP
TOP VIEW
SDO/S3 4
15 PROG_SEL
EXT_CAP0 5
14 EXT_CAP1
VDD 6
OUT2 12
OUT2 11
S5 10
S4 9
OUT1 7
OUT1 8
13 VDD
NOTES
1. THE EXPOSED DIE PAD MUST BE CONNECTED
TO GROUND (VSS).
11367-002
OUT0 3
Figure 2. Pin Configuration
Table 12. Pin Function Descriptions
Pin No.
1
Mnemonic
CS/S2
2
3
4
OUT0
OUT0
SDO/S3
5
6
7
8
9
EXT_CAP0
VDD
OUT1
OUT1
S4
10
S5
11
12
13
14
15
OUT2
OUT2
VDD
EXT_CAP1
PROG_SEL
16
17
18
OUT3
OUT3
RESET
Description
Chip Select (CS)/Pin Programming (S2). This dual-purpose pin is controlled by the PROG_SEL pin. In SPI mode,
CS is an active low CMOS input. When programming the device in SPI mode, CS must be held low. In systems
with two or more AD9508-EP devices, CS enables individual programming of each device. In pin programming
mode, S2 is hardwired with a resistor to either VDD or ground. The resistor value and resistor biasing determine
the channel divider value for the outputs on Pin 11 and Pin 12.
LVDS/HSTL Differential Output or Single-Ended CMOS Output.
Complementary LVDS/HSTL Differential Output or Single-Ended CMOS Output.
SPI Serial Data Output (SDO)/Pin Programming (S3). This dual-purpose pin is controlled by the PROG_SEL pin. In
SPI mode, SDO can be configured as an output to read back the internal register settings. In pin programming
mode, S3 is hardwired with a resistor to either VDD or ground. The resistor value and resistor biasing determine
the channel divider value for the outputs on Pin 16 and Pin 17.
Node for External Decoupling Capacitor for LDO Regulator. Tie this pin with a 0.47 µF capacitor to ground.
Power Supply (2.5 V Operation).
LVDS/HSTL Differential Output or Single-Ended CMOS Output.
Complementary LVDS/HSTL Differential Output or Single-Ended CMOS Output.
The S4 pin is used in pin programming mode only. (The PROG_SEL pin determines which programming mode is
used.) S4 is hardwired with a resistor to either VDD or ground. The resistor value and resistor biasing determine
the output logic levels used for the outputs on Pin 2, Pin 3, Pin 7, and Pin 8.
The S5 pin is used in pin programming mode only. (The PROG_SEL pin determines which programming mode is
used.) S5 is hardwired with a resistor to either VDD or ground. The resistor value and resistor biasing determine
the output logic levels used for the outputs on Pin 11, Pin 12, Pin 16, and Pin 17.
LVDS/HSTL Differential Output or Single-Ended CMOS Output.
Complementary LVDS/HSTL Differential Output or Single-Ended CMOS Output.
Power Supply (2.5 V Operation).
Node for External Decoupling Capacitor for LDO Regulator. Tie this pin with a 0.47 µF capacitor to ground.
Three-State CMOS Input. Pin 15 selects the device programming interface used by the AD9508-EP: SPI, I2C, or
pin programming.
LVDS/HSTL Differential Output or Single-Ended CMOS Output.
Complementary LVDS/HSTL Differential Output or Single-Ended CMOS Output.
Device Reset (CMOS Input, Active Low). When this pin is asserted, the internal register settings revert to their
default state after the RESET pin is released. RESET also powers down the device when an active low signal is
applied to the pin. The RESET pin has an internal 24 kΩ pull-up resistor.
Rev. B | Page 11 of 19
AD9508-EP
Pin No.
19
Mnemonic
SCLK/SCL/S0
20
SYNC
21
CLK
22
23
CLK
IN_SEL
24
SDIO/SDA/S1
EP
Enhanced Product
Description
SPI Serial Clock (SCLK)/I2C Serial Clock (SCL)/Pin Programming (S0). This multipurpose pin is controlled by the
PROG_SEL pin. In SPI mode, SCLK is the serial clock. In I2C mode, SCL is the serial clock. In pin programming mode,
S0 is hardwired with a resistor to either VDD or ground. The resistor value and resistor biasing determine the
channel divider value for the outputs on Pin 2 and Pin 3.
Clock Synchronization (Active Low). When this pin is asserted, the output drivers are held static and then
synchronized on a low-to-high transition of this pin. The SYNC pin has an internal 24 kΩ pull-up resistor.
Differential Clock Input or Single-Ended CMOS Input. This pin serves as a differential clock input or as a singleended CMOS input, depending on the logic state of the IN_SEL pin.
Complementary Differential Clock Input.
Input Select (CMOS Input). A logic high on this pin configures the CLK and CLK inputs for a differential input
signal. A logic low configures the CLK input for single-ended CMOS; ac-couple the unused CLK pin to ground
with a 0.1 μF capacitor.
SPI Serial Data Input and Output (SDIO)/I2C Serial Data (SDA)/Pin Programming (S1). This multipurpose pin
is controlled by the PROG_SEL pin. In SPI mode, SDIO is the serial input/output pin. In 4-wire SPI mode, data
writes occur on this pin; in 3-wire SPI mode, both data reads and writes occur on this pin. This pin has no internal
pull-up/pull-down resistor. In I2C mode, SDA is the serial data pin. In pin programming mode, S1 is hardwired
with a resistor to either VDD or ground. The resistor value and resistor biasing determine the channel divider
values for the outputs on Pin 7 and Pin 8.
Exposed Pad. The exposed die pad must be connected to ground (VSS).
Rev. B | Page 12 of 19
Enhanced Product
AD9508-EP
TYPICAL PERFORMANCE CHARACTERISTICS
TIME (250ps/DIV)
700
600
500
400
100
300
500
700
900
1100
1300
1500
FREQUENCY (MHz)
11367-006
11367-003
VOLTAGE (100mV/DIV)
DIFFERENTIAL OUTPUT SWING (mV p-p)
800
Figure 6. LVDS Differential Output Swing vs. Frequency
Figure 3. LVDS Differential Output Waveform at 800 MHz
TIME (1.5ns/DIV)
780
760
740
720
700
2.3
2.5
2.7
2.9
3.1
3.3
3.5
POWER SUPPLY VOLTAGE (V)
Figure 4. LVDS Differential Output Waveform at 156.25 MHz
200
Figure 7. LVDS Differential Output Swing vs. Power Supply Voltage
2.4
ONE OUTPUT
TWO OUTPUTS
THREE OUTPUTS
FOUR OUTPUTS
2.3
PROPAGATION DELAY (ns)
150
CURRENT (mA)
11367-008
11367-004
VOLTAGE (100mV/DIV)
DIFFERENTIAL OUTPUT SWING (mV p-p)
800
100
50
2.2
2.1
2.0
1.9
0
400
800
FREQUENCY (MHz)
1200
1600
Figure 5. Power Supply Current vs. Frequency and Number of Outputs Used,
LVDS Mode
Rev. B | Page 13 of 19
1.7
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
INPUT DIFFERENTIAL VOLTAGE (V p-p)
Figure 8. LVDS Propagation Delay vs. Input Differential Voltage
11367-009
0
11367-005
1.8
AD9508-EP
Enhanced Product
2.6
VOLTAGE (300mV/DIV)
PROPAGATION DELAY (ns)
2.4
2.2
2.0
1.8
700
500
900
1100
1300
1500
COMMON-MODE VOLTAGE (mV)
TIME (5ns/DIV)
11367-010
1.4
300
Figure 12. CMOS Output Waveform at 50 MHz with 10 pF Load
Figure 9. LVDS Propagation Delay vs. Input Common-Mode Voltage
60
125
DIVIDER 1
DIVIDER 2 (FREQUENCY RANGE NORMALIZED FROM 0Hz TO 800MHz)
DIVIDER 3 (FREQUENCY RANGE NORMALIZED FROM 0Hz TO 500MHz)
55
ONE OUTPUT
TWO OUTPUTS
THREE OUTPUTS
FOUR OUTPUTS
FIVE OUTPUTS
SIX OUTPUTS
SEVEN OUTPUTS
EIGHT OUTPUTS
CURRENT (mA)
100
50
45
75
0
200
400
600
800
1000
1200
1400
1600
FREQUENCY (MHz)
25
25
11367-011
40
50
75
100
125
150
175
200
225
250
FREQUENCY (MHz)
11367-014
50
Figure 13. Power Supply Current vs. Frequency and Number of Outputs Used,
CMOS Mode
Figure 10. LVDS Output Duty Cycle vs. Output Frequency
1.9
300Ω LOAD
500Ω LOAD
750Ω LOAD
1kΩ LOAD
1.8
OUTPUT SWING (V p-p)
VOLTAGE (300mV/DIV)
1.7
1.6
TIME (1.25ns/DIV)
1.4
0
50
100
150
200
250
FREQUENCY (MHz)
Figure 14. CMOS Output Swing vs. Frequency and Resistive Load
Figure 11. CMOS Output Waveform at 200 MHz with 10 pF Load
Rev. B | Page 14 of 19
11367-015
1.5
11367-012
DUTY CYCLE (%)
11367-013
1.6
Enhanced Product
AD9508-EP
2.0
–55°C
+25°C
+105°C
VOLTAGE (300mV/DIV)
OUTPUT SWING (V p-p)
1.8
1.6
1.4
50
100
150
200
250
FREQUENCY (MHz)
TIME (1.5ns/DIV)
Figure 18. HSTL Differential Output Waveform at 156.25 MHz
200
1.7
150
CURRENT (mA)
1.9
2pF LOAD
5pF LOAD
10pF LOAD
20pF LOAD
0
50
100
150
200
250
100
FREQUENCY (MHz)
Figure 16. CMOS Output Swing vs. Frequency and Capacitive Load
0
11367-017
1.1
ONE OUTPUT
TWO OUTPUTS
THREE OUTPUTS
FOUR OUTPUTS
50
1.3
0
400
800
1200
1600
FREQUENCY (MHz)
Figure 19. Power Supply Current vs. Frequency and Number of Outputs Used,
HSTL Mode
11367-018
TIME (250ps/DIV)
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
100
300
500
700
900
1100
1300
1500
FREQUENCY (MHz)
Figure 20. HSTL Differential Output Swing vs. Frequency
Figure 17. HSTL Differential Output Waveform at 800 MHz
Rev. B | Page 15 of 19
11367-007
DIFFERENTIAL OUTPUT SWING (V p-p)
2.0
VOLTAGE (300mV/DIV)
OUTPUT SWING (V p-p)
Figure 15. CMOS Output Swing vs. Frequency and Temperature (10 pF Load)
1.5
11367-019
0
11367-020
1.0
11367-115
1.2
AD9508-EP
Enhanced Product
60
DUTY CYCLE (%)
55
1.8
1.7
50
45
2.7
2.9
3.1
3.5
3.3
POWER SUPPLY VOLTAGE (V)
40
0
2.3
140
2.2
130
JITTER (fs rms)
150
2.1
2.0
1.8
90
1.2
1.4
1.6
1.8
2.0
INPUT DIFFERENTIAL VOLTAGE (V p-p)
80
11367-022
1.0
1400
1600
110
100
0.8
1200
120
1.9
0.6
1000
Figure 24. HSTL Output Duty Cycle vs. Output Frequency
2.4
0.4
800
600
400
FREQUENCY (MHz)
Figure 21. HSTL Differential Output Swing vs. Power Supply Voltage
1.7
0.2
200
0
2
4
8
6
10
SLEW RATE (V/ns)
Figure 22. HSTL Propagation Delay vs. Input Differential Voltage
Figure 25. Additive Broadband Jitter vs. Input Slew Rate,
LVDS and HSTL Modes (Calculated from SNR of ADC Method)
2.6
–80
11367-227
2.5
11367-024
1.6
1.5
2.3
PROPAGATION DELAY (ns)
DIVIDER 1
DIVIDER 2 (FREQUENCY RANGE NORMALIZED FROM 0Hz TO 800MHz)
DIVIDER 3 (FREQUENCY RANGE NORMALIZED FROM 0Hz TO 500MHz)
1.9
11367-021
DIFFERENTIAL OUTPUT SWING (V p-p)
2.0
HSTL 155.52MHz
HSTL 311.04MHz
HSTL 622.08MHz
–90
–100
PHASE NOISE (dBc/Hz)
PROPAGATION DELAY (ns)
2.4
2.2
2.0
1.8
–110
–120
–130
–140
–150
1.6
500
700
900
1100
COMMON-MODE VOLTAGE (mV)
1300
1500
–170
10
11367-023
1.4
300
Figure 23. HSTL Propagation Delay vs. Input Common-Mode Voltage
100
1k
10k
100k
1M
FREQUENCY OFFSET (Hz)
10M
100M
11367-228
–160
Figure 26. Absolute Phase Noise in HSTL Mode with Clock Input at
622.08 MHz and Outputs = 622.08 MHz, 311.04 MHz, and 155.52 MHz
Rev. B | Page 16 of 19
Enhanced Product
AD9508-EP
–80
–90
–90
–100
–100
PHASE NOISE (dBc/Hz)
–110
–120
–130
–140
–110
1
–120
MARKER
FREQUENCY
AMPLITUDE
1.
2.
3.
4.
5.
6.
7.
–116.04dBc/Hz
–126.68dBc/Hz
–135.27dBc/Hz
–142.56dBc/Hz
–159.42dBc/Hz
–161.97dBc/Hz
–164.55dBc/Hz
10Hz
100Hz
1kHz
10kHz
100.5kHz
1MHz
10MHz
2
–130
3
4
–140
–150
5
1k
10k
100k
1M
10M
100M
FREQUENCY OFFSET (Hz)
–170
10
–90
–90
–100
–100
PHASE NOISE (dBc/Hz)
–80
–120
–130
–140
1k
10k
100k
1M
1
–110
2
–120
MARKER
FREQUENCY
AMPLITUDE
1.
2.
3.
4.
5.
6.
7.
8.
–112.35dBc/Hz
–118.81dBc/Hz
–127.84dBc/Hz
–135.97dBc/Hz
–151.91dBc/Hz
–157.87dBc/Hz
–159.78dBc/Hz
–157.88dBc/Hz
10Hz
100Hz
1kHz
10kHz
100.5kHz
1MHz
10MHz
20MHz
4
–140
–150
–160
–160
5
6
1k
10k
1M
100k
10M
100M
FREQUENCY OFFSET (Hz)
–170
10
11367-230
100
100M
3
–130
–150
–170
10
10M
Figure 30. Additive Phase Noise with Clock Input = 1200 MHz
and HSTL Outputs = 100 MHz
–80
–110
100
FREQUENCY (Hz)
Figure 27. Absolute Phase Noise in LVDS Mode with Clock Input at
622.08 MHz and Outputs = 622.08 MHz, 311.04 MHz, and 155.52 MHz
100
1k
10k
100k
1M
7
8
10M
100M
FREQUENCY (Hz)
Figure 28. Absolute Phase Noise of Clock Source at 622.08 MHz
Figure 31. Additive Phase Noise with Clock Input = 622.08 MHz
and HSTL Outputs = 155.52 MHz
–80
–80
–90
2
–100
3
–110
4
–120
–130
MARKER
FREQUENCY
AMPLITUDE
1.
2.
3.
4.
5.
6.
7.
8.
–89.57dBc/Hz
–100.45dBc/Hz
–109.97dBc/Hz
–116.93dBc/Hz
–135.33dBc/Hz
–144.39dBc/Hz
–148.66dBc/Hz
–149.78dBc/Hz
10Hz
100Hz
1kHz
10kHz
100kHz
1MHz
10MHz
100MHz
–90
1
–100
PHASE NOISE (dBc/Hz)
1
5
–140
6
7
8
2
–110
–140
–160
–160
100
1k
10k
100k
1M
10M
100M
FREQUENCY (Hz)
4
MARKER
FREQUENCY
AMPLITUDE
1.
2.
3.
4.
5.
6.
7.
8.
–100.17dBc/Hz
–109.18dBc/Hz
–117.67dBc/Hz
–124.94dBc/Hz
–143.83dBc/Hz
–151.64dBc/Hz
–153.81dBc/Hz
–152.87dBc/Hz
10Hz
100Hz
1kHz
10kHz
100.5kHz
1MHz
10MHz
20MHz
–130
–150
–170
10
3
–120
–150
11367-329
PHASE NOISE (dBc/Hz)
7
–170
10
5
100
1k
10k
100k
6
7
1M
10M
8
100M
FREQUENCY (Hz)
Figure 32. Additive Phase Noise with Clock Input = 622.08 MHz
and LVDS Outputs = 622.08 MHz
Figure 29. Additive Phase Noise with Clock Input = 1200 MHz
and HSTL Outputs = 1200 MHz
Rev. B | Page 17 of 19
11367-129
100
11367-229
–160
10
PHASE NOISE (dBc/Hz)
6
–160
11367-330
–150
11367-130
PHASE NOISE (dBc/Hz)
–80
LVDS 155.52MHz
LVDS 311.04MHz
LVDS 622.08MHz
AD9508-EP
Enhanced Product
–80
–90
–110 1
–120
AMPLITUDE
1.
2.
3.
4.
5.
6.
7.
8.
–114.15dBc/Hz
–127.18dBc/Hz
–134.13dBc/Hz
–141.63dBc/Hz
–154.66dBc/Hz
–155.37dBc/Hz
–152.86dBc/Hz
–153.09dBc/Hz
10Hz
100Hz
1kHz
10kHz
100.5kHz
1MHz
10MHz
20MHz
2
–130
3
4
–140
–150
5
6
100k
1M
7
8
–160
–170
10
100
1k
10k
10M
100M
FREQUENCY (Hz)
11367-131
PHASE NOISE (dBc/Hz)
–100
MARKER
FREQUENCY
Figure 33. Additive Phase Noise with Clock Input = 100 MHz
and CMOS Outputs = 100 MHz
Rev. B | Page 18 of 19
Enhanced Product
AD9508-EP
OUTLINE DIMENSIONS
0.30
0.25
0.18
0.50
BSC
PIN 1
INDICATOR
24
19
18
1
EXPOSED
PAD
0.50
0.40
0.30
TOP VIEW
0.80
0.75
0.70
13
12
2.65
2.50 SQ
2.45
6
7
0.25 MIN
BOTTOM VIEW
0.05 MAX
0.02 NOM
FOR PROPER CONNECTION OF
THE EXPOSED PAD, REFER TO
THE PIN CONFIGURATION AND
FUNCTION DESCRIPTIONS
SECTION OF THIS DATA SHEET.
COPLANARITY
0.08
0.20 REF
SEATING
PLANE
COMPLIANT TO JEDEC STANDARDS MO-220-WGGD.
04-12-2012-A
PIN 1
INDICATOR
4.10
4.00 SQ
3.90
Figure 34. 24-Lead Lead Frame Chip Scale Package [LFCSP_WQ]
4 mm × 4 mm Body, Very Very Thin Quad
(CP-24-7)
Dimensions shown in millimeters
ORDERING GUIDE
Model1
AD9508SCPZ-EP
AD9508SCPZ-EP-R7
AD9508/PCBZ
1
Temperature Range
−55°C to +105°C
−55°C to +105°C
Package Description
24-Lead Lead Frame Chip Scale Package (LFCSP_WQ)
24-Lead Lead Frame Chip Scale Package (LFCSP_WQ)
Evaluation Board
Z = RoHS Compliant Part.
I2C refers to a communications protocol originally developed by Philips Semiconductors (now NXP Semiconductors).
©2013–2014 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D11367-0-10/14(B)
Rev. B | Page 19 of 19
Package Option
CP-24-7
CP-24-7