Datasheet ADCLK948 Datasheet (ANALOG DEVICES)

Two Selectable Inputs, 8 LVPECL Outputs,

FEATURES FEATURES

2 selectable differential inputs 2 selectable differential inputs

4.8 GHz operating frequency 4.8 GHz operating frequency 75 fs rms broadband random jitter 75 fs rms broadband random jitter On-chip input terminations On-chip input terminations

3.3 V power supply 3.3 V power supply

APPLICATIONS APPLICATIONS

Low jitter clock distribution Low jitter clock distribution Clock and data signal restoration Clock and data signal restoration Level translation Level translation Wireless communications Wireless communications Wired communications Wired communications Medical and industrial imaging Medical and industrial imaging ATE and high performance instrumentation ATE and high performance instrumentation

GENERAL DESCRIPTION GENERAL DESCRIPTION

The ADCLK948 is an ultrafast clock fanout buffer fabricated

The ADCLK948 is an ultrafast clock fanout buffer fabricated on the Analog Devices, Inc., proprietary XFCB3 silicon germanium

on the Analog Devices, Inc., proprietary XFCB3 silicon germanium (SiGe) bipolar process. This device is designed for high speed

(SiGe) bipolar process. This device is designed for high speed applications requiring low jitter.

applications requiring low jitter.

The device has two selectable differential inputs via the IN_SEL

The device has two selectable differential inputs via the IN_SEL control pin. Both inputs are equipped with center tapped,

control pin. Both inputs are equipped with center tapped, differential, 100 Ω on-chip termination resistors. The inputs

differential, 100 Ω on-chip termination resistors. The inputs accept dc-coupled LVPECL, CML, 3.3 V CMOS (single-ended),

accept dc-coupled LVPECL, CML, 3.3 V CMOS (single-ended), and ac-coupled 1.8 V CMOS, LVDS, and LVPECL inputs. A

and ac-coupled 1.8 V CMOS, LVDS, and LVPECL inputs. A V

V

x pin is available for biasing ac-coupled inputs.

REF

The ADCLK948 features eight full-swing emitter coupled logic

The ADCLK948 features eight full-swing emitter coupled logic (ECL) output drivers. For LVPECL (positive ECL) operation,

(ECL) output drivers. For LVPECL (positive ECL) operation, bias V

bias V operation, bias V

operation, bias V

The output stages are designed to directly drive 800 mV each

The output stages are designed to directly drive 800 mV each side into 50 Ω terminated to V

side into 50 Ω terminated to V output swing of 1.6 V.

output swing of 1.6 V.

The ADCLK948 is available in a 32-lead LFCSP and specified

The ADCLK948 is available in a 32-lead LFCSP and specified for operation over the standard industrial temperature range of

for operation over the standard industrial temperature range of

−40°C to +85°C.

to the positive supply and VEE to ground. For ECL

CC

to ground and VEE to the negative supply.

CC

− 2 V for a total differential

CC

SiGe Clock Fanout Buffer

ADCLK948

FUNCTIONAL BLOCK DIAGRAM FUNCTIONAL BLOCK DIAGRAM

ADCLK948

V

REF

VT0

CLK0

VT1

CLK1

IN_SEL

V

REF

0

1

REFERENCE

Figure 1.

LVPECL

Q0

Q1

Q2

Q3

Q4

Q5

Q6

Q7

08280-001

Rev. A

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners.

ADCLK948

REVISION HISTORY

6/10—Rev. 0 to Rev. A

Changed Output Voltage Differential Parameter to Output

Voltage, Single Ended Parameter, Table 1 ..................................... 3

Changes to Output Voltage, Single Ended Parameter, Table 1 ... 3

7/09—Revision 0: Initial Version

Pin Configuration and Function Descriptions ..............................6

Typical Performance Characteristics ..............................................7

Functional Description .....................................................................9

Clock Inputs ...................................................................................9

Clock Outputs ................................................................................9

Clock Input Select (IN_SEL) Settings...................................... 10

PCB Layout Considerations ...................................................... 10

Input Termination Options ....................................................... 11

Outline Dimensions ....................................................................... 12

Ordering Guide .......................................................................... 12

Rev. A | Page 2 of 12

ADCLK948

SPECIFICATIONS

ELECTRICAL CHARACTERISTICS

Typical (Typ column) values are given for VCC − VEE = 3.3 V and TA = 25°C, unless otherwise noted. Minimum (Min column) and maximum (Max column) values are given over the full V

Table 1. Clock Inputs and Outputs

Parameter Symbol Min Typ Max Unit Test Conditions/Comments

DC INPUT CHARACTERISTICS

Input Common Mode Voltage V

VEE + 1.5 VCC − 0.1 V

ICM

Input Differential Range VID 0.4 3.4 V p-p ±1.7 V between input pins Input Capacitance CIN 0.4 pF Input Resistance

Single-Ended Mode 50 Ω Differential Mode 100 Ω

Common Mode 50 kΩ Open VTx Input Bias Current 20 µA Hysteresis 10 mV

DC OUTPUT CHARACTERISTICS

Output Voltage High Level VOH V Output Voltage Low Level VOL V Output Voltage, Single Ended VO 610 960 mV VOH − VOL, output static Reference Voltage V

REF

Output Voltage (VCC + 1)/2 V −500 µA to +500 µA

Output Resistance 235 Ω

− VEE = 3.3 V ± 10% and TA = −40°C to +85°C variation, unless otherwise noted.

CC

− 1.26 VCC − 0.76 V 50 Ω to (VCC − 2.0 V)

CC

− 1.99 VCC − 1.54 V 50 Ω to (VCC − 2.0 V)

CC

Table 2. Timing Characteristics

Parameter Symbol Min Typ Max Unit Test Conditions/Comments

AC PERFORMANCE

Maximum Output Frequency 4.5 4.8 GHz

See Figure 4 for differential output voltage vs.

frequency, >0.8 V differential output swing Output Rise Time tR 40 75 90 ps 20% to 80% measured differentially Output Fall Time tF 40 75 90 ps Propagation Delay tPD 175 210 245 ps V

= 2 V, VID = 1.6 V p-p

ICM

Temperature Coefficient 50 fs/°C

Output-to-Output Skew

1

9 25 ps Part-to-Part Skew 45 ps VID = 1.6 V p-p Additive Time Jitter

Integrated Random Jitter 28 fs rms BW = 12 kHz − 20 MHz, CLK = 1 GHz Broadband Random Jitter2 75 fs rms VID = 1.6 V p-p, 8 V/ns, V Crosstalk-Induced Jitter

3

90 fs rms

ICM

= 2 V

CLOCK OUTPUT PHASE NOISE

Absolute Phase Noise

Input slew rate > 1 V/ns (see Figure 11, the phase noise plot, for more details)

fIN = 1 GHz −119 dBc/Hz @100 Hz offset

−134 dBc/Hz @1 kHz offset

−145 dBc/Hz @10 kHz offset

−150 dBc/Hz @100 kHz offset

−150 dBc/Hz >1 MHz offset

1

The output skew is the difference between any two similar delay paths while operating at the same voltage and temperature.

2

Measured at the rising edge of the clock signal; calculated using the SNR of the ADC method.

3

This is the amount of added jitter measured at the output while two related, asynchronous, differential frequencies are applied to the inputs.

Rev. A | Page 3 of 12

ADCLK948

Table 3. Input Select Control Pin

Parameter Symbol Min Typ Max Unit

Logic 1 Voltage VIH V Logic 0 Voltage VIL V Logic 1 Current IIH 100 A Logic 0 Current IIL 0.6 mA Capacitance 2 pF

Table 4. Power

Parameter Symbol Min Typ Max Unit Test Conditions/Comments

POWER SUPPLY

Supply Voltage Requirement VCC − VEE 2.97 3.63 V 3.3 V + 10% Power Supply Current Static

Negative Supply Current I

Positive Supply Current I Power Supply Rejection Output Swing Supply Rejection

1

Change in tPD per change in VCC.

2

Change in output swing per change in VCC.

1

2

96 120 mA VCC − VEE = 3.3 V ± 10%

VEE

288 330 mA VCC − VEE = 3.3 V ± 10%

VCC

PSR

<3 ps/V VCC − VEE = 3.3 V ± 10%

VCC

PSR

28 dB VCC − VEE = 3.3 V ± 10%

VCC

− 0.4 VCC V

CC

1 V

EE

Rev. A | Page 4 of 12

ADCLK948

ABSOLUTE MAXIMUM RATINGS

Table 5.

Parameter Rating

Supply Voltage

VCC − VEE 6 V

Input Voltage

CLK0, CLK1, CLK0, CLK1, IN_SEL VEE − 0.5 V to

+ 0.5 V

V

CC

CLK0, CLK1, CLK0, CLK1 to VTx Pin (CML,

±40 mA

LVPECL Termination)

CLK0, CLK1 to CLK0, CLK1 Input Termination, VTx to CLK0, CLK1, CLK0,

±1.8 V ±2 V

and CLK1 Maximum Voltage on Output Pins VCC + 0.5 V Maximum Output Current 35 mA Voltage Reference (V

x) VCC to VEE

REF

Ope rating Temperature R ange

Ambient −40°C to +85°C Junction 150°C

Storage Temperature Range −65°C to +150°C

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.

DETERMINING JUNCTION TEMPERATURE

To determine the junction temperature on the application printed circuit board (PCB), use the following equation:

T

= T

J

+ (ΨJT × PD)

CASE

where:

T

is the junction temperature (°C).

J

T

is the case temperature (°C) measured by the customer at

CASE

the top center of the package.

is from Tabl e 6.

Ψ

JT

P

is the power dissipation.

D

Val u es o f θ design considerations. θ mation of T

where T

Val u es o f θ

are provided for package comparison and PCB

JA

can be used for a first-order approxi-

JA

by the equation

J

T

= TA + (

J

θ

× PD)

JA

is the ambient temperature (°C).

A

are provided in Tab l e 6 for package comparison

JB

and PCB design considerations.

ESD CAUTION

THERMAL PERFORMANCE

Table 6.

Parameter Symbol Description Value

Junction-to-Ambient Thermal Resistance

θ

JA

Still Air Per JEDEC JESD51-2

0 m/sec Air Flow 49.8 °C/W

Moving Air

θ

JMA

Per JEDEC JESD51-6

1 m/sec Air Flow 43.5 °C/W

2.5 m/sec Air Flow 39.0 °C/W

Junction-to-Board Thermal Resistance

θ

JB

Moving Air Per JEDEC JESD51-8

1 m/sec Air Flow 30.7 °C/W Junction-to-Case Thermal Resistance

θ

JC

Moving Air Per MIL-STD 883, Method 1012.1

Die-to-Heatsink 8.8 °C/W Junction-to-Top-of-Package Characterization Parameter

Ψ

JT

Still Air Per JEDEC JESD51-2

0 m/sec Air Flow 0.7 °C/W

1

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 if they are similar to those assumed in these calculations.

1

Unit

Rev. A | Page 5 of 12

ADCLK948

2

V

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

CC

Q0

IN_SEL

Q0

V

29

30

31

32

CC

Q1

V

25

28

27

26

1CLK0

PIN 1

2CLK0

INDICATO R

3

0

REF

0

T

1

T

1

REF

NOTES

1. NC = NO CONNECT . . EPAD MUST BE SOLDERED TO

4V 5CLK1 6CLK1 7V 8

ADCLK948

TOP VIEW

(Not to Scale)

9

11

10

12

13

C

CC

Q7

Q6

N

V

24 Q2 23 Q2 22 Q3 21 Q3 20 Q4 19 Q4 18 Q5 17 Q5

16

14

15

CC

Q6

V

POWER PLANE.

EE

Figure 2. Pin Configuration

Table 7. Pin Function Descriptions

Pin No. Mnemonic Description

1 CLK0 Differential Input (Positive) 0. 2 3 V

CLK0

REF

4 VT0

0

Differential Input (Negative) 0. Reference Voltage. Reference voltage for biasing ac-coupled CLK0 and CLK0

Center Tap. Center tap of a 100 Ω input resistor for CLK0 and CLK0 5 CLK1 Differential Input (Positive) 1. 6

CLK1 7 VT1 8 V

REF

1

Differential Input (Negative) 1. Center Tap. Center tap of a 100 Ω input resistor for CLK1 and CLK1 Reference Voltage. Reference voltage for biasing ac-coupled CLK1 and CLK1

9 NC No Connection. 10, 15, 16, 25, 26, 31 VCC Positive Supply Pin. 11, 12

13, 14 17, 18 19, 20 21, 22 23, 24 27, 28 29, 30

Q7

Q6

Q5

Q4

Q3

Q2

Q1

Q0

, Q7 , Q6 , Q5 , Q4 , Q3 , Q2 , Q1 , Q0

32 IN_SEL

Differential LVPECL Outputs. Differential LVPECL Outputs. Differential LVPECL Outputs. Differential LVPECL Outputs. Differential LVPECL Outputs. Differential LVPECL Outputs. Differential LVPECL Outputs. Differential LVPECL Outputs. Input Select. Logic 0 selects CLK0 and CLK0

inputs. Logic 1 selects CLK1 and CLK1 inputs.

EPAD The exposed pad (EPAD) must be connected to VEE.

8280-002

inputs.

Rev. A | Page 6 of 12

ADCLK948

TYPICAL PERFORMANCE CHARACTERISTICS

VCC = 3.3 V, VEE = 0 V, V

ICM

= V

x, T

= 25°C, clock outputs terminated at 50 Ω to VCC − 2 V, unless otherwise noted.

REF

A

C3

C4

100mV/DIV 500ps/DIV

Figure 3. LVPECL Output Waveform @ 200 MHz

1.8

1.7

1.6

1.5

1.4

1.3

1.2

1.1

1.0

0.9

0.8

0.7

0.6

DIFFERENTIAL OUTP UT VOLTAGE (V)

0.5

0.4 0 1000 2000 3000 4000 5000

FREQUENCY (MHz)

Figure 4. Differential Output Voltage vs. Frequency, V

225

220

215

210

205

200

195

PROPAGATION DELAY (ps)

190

185

180

011.61.41.21.00.80.60. 40.2

DIFFERENTIAL INPUT VOLTAGE SWING (V)

Figure 5. Propagation Delay vs. Differential Input Voltage

> 1.1 V p-p

ID

C4

C3

08280-003

100mV/DIV 1 00ps/DIV

Figure 6. LVPECL Output Waveform @ 1000 MHz

214

213

212

211

210

209

PROPAGATION DELAY (ps)

208

207

–40 806040200–20

08280-004

TEMPERATURE (° C)

Figure 7. Propagation Delay vs. Temperature, VID = 1.6 V p-p

230

220

210

200

PROPAGATION DELAY (ps)

.8

08280-005

190

0.9 3.12.92.72.52.32.11.91. 71.51.31.1

DC COMMON-MO DE VOLTAG E (V)

Figure 8. Propagation Delay vs. DC Common-Mode Voltage vs. Temperature,

Input Slew Rate > 25 V/ns

+85°C

+25°C

–40°C

08280-006

08280-007

08280-008

Rev. A | Page 7 of 12

ADCLK948

–

1.56

1.54

1.52

1.50

1.48

1.46

1.44

DIFFERENT IAL OUTPUT VOLT AGE SWING (V)

1.42

2.75 2.85 2.95 3.05 3.15 3.25 3.35 3.45 3.55 3.65 3.75

–40°C

+25°C

+85°C

POWER SUPPLY (V)

Figure 9. Differential Output Voltage Swing vs. Power Supply Voltage vs.

Temperature, V

350

300

= 1.6 V p-p

ID

ICC

08280-009

PHASE NOISE (d Bc/Hz)

90

–100

–110

–120

–130

–140

–150

–160

–170

ABSOLUTE PHAS E NOISE M EASURED @ 1 GHz WI TH AGI LENT E5052 USI NG WENZE L CLOCK SO URCE CONSI STING O F A WENZEL 100MHz CRYSTAL OSCILLATOR (P/N 500-06672), WENZEL 5× MULTIPLIER (P/N LNOM-100-5-13-14-F-A), AND A WENZEL 2× MULTIPLIER (P/N LNDD-500-14-14-1-D).

ADCLK948

CLOCK SOURCE

10 100 1k 10k 100k 1M 10M 100M

FREQUENCY OFFSET (Hz)

Figure 11. Absolute Phase Noise Measured @1 GHz

300

250

08280-011

250

200

150

100

SUPPLY CURRENT (mA)

50

0

2.75 3.753.503.253.00

+85°C +25°C –40°C

IEE

SUPPLY VOLTAGE (V)

Figure 10. Power Supply Current vs. Power Supply Voltage vs. Temperature,

All Outputs Loaded (50 Ω to V

− 2 V).

CC

200

rms)

S

150

100

RANDOM JITTER (f

50

0

022015105

08280-010

INPUT SLEW RATE ( V/ns)

5

08280-012

Figure 12. RMS Random Jitter vs. Input Slew Rate, VID Method

Rev. A | Page 8 of 12

ADCLK948

V

A

V

A

FUNCTIONAL DESCRIPTION

CLOCK INPUTS

The ADCLK948 accepts a differential clock input from one of two inputs and distributes the selected clock to all eight LVPECL outputs. The maximum specified frequency is the point at which the output voltage swing is 50% of the standard LVPECL swing (see Figure 4). See the functional block diagram (Figure 1) and the General Description section for more clock input details. See Figure 19 through Figure 23 for various clock input termination schemes.

Output jitter performance is degraded by an input slew rate below 4 V/ns, as shown in Figure 12. The ADCLK948 is specifically designed to minimize added random jitter over a wide input slew rate range. Whenever possible, clamp excessively large input signals with fast Schottky diodes because attenuators reduce the slew rate. Input signal runs of more than a few centimeters should be over low loss dielectrics or cables with good high frequency characteristics.

CLOCK OUTPUTS

The specified performance necessitates using proper transmission line terminations. The LVPECL outputs of the ADCLK948 are designed to directly drive 800 mV into a 50 Ω cable or into microstrip/stripline transmission lines terminated with 50  referenced to V output stage is shown in Figure 13. The outputs are designed for best transmission line matching. If high speed signals must be routed more than a centimeter, either the microstrip or the stripline technique is required to ensure proper transition times and to prevent excessive output ringing and pulse width dependent propagation delay dispersion.

Figure 13. Simplified Schematic Diagram of the LVPECL Output Stage

Figure 14 through Figure 17 depict various LVPECL output termination schemes. When dc-coupled, V should match VS_DRV.

− 2 V, as shown in Figure 14. The LVPECL

CC

V

CC

Qx

V

EE

S

08280-013

of the receiving buffer

Thevenin-equivalent termination uses a resistor network to provide 50 Ω termination to a dc voltage that is below V

of

OL

the LVPECL driver. In this case, VS_DRV on the ADCLK948 should equal V

of the receiving buffer. Although the resistor

S

combination shown (in Figure 15) results in a dc bias point of VS_DRV − 2 V, the actual common-mode voltage is VS_DRV −

1.3 V because there is additional current flowing from the ADCLK948 LVPECL driver through the pull-down resistor.

LVPECL Y-termination is an elegant termination scheme that uses the fewest components and offers both odd- and even-mode impedance matching. Even-mode impedance matching is an important consideration for closely coupled transmission lines at high frequencies. Its main drawback is that it offers limited flexibility for varying the drive strength of the emitter follower LVPECL driver. This can be an important consideration when driving long trace lengths but is usually not an issue.

S_DRV

DCLK948

Z0 = 50Ω

VCC – 2V

Z0 = 50Ω

Figure 14. DC-Coupled, 3.3 V LVPECL

S_DRV

VS_DRV

ADCLK948

SINGLE-ENDED

(NOT COUPL ED)

50Ω

Figure 15. DC-Coupled, 3.3 V LVPECL Far-End Thevenin Termination

VS_DRV

DCLK948

Z0 = 50Ω

50Ω

Z0 = 50Ω

Figure 16. DC-Coupled, 3.3 V LVPECL Y-Termination

VS_DRV

DCLK948

0.1nF

200Ω 200Ω

100Ω DIFFERENTIAL

(COUPLED)

TRANSMISSION LINE

Figure 17. AC-Coupled, LVPECL with Parallel Transmission Line

= VS_DR

S

50Ω

LVPECL

50Ω

V

127Ω127Ω

LVPECL

83Ω83Ω

VS = VS_DRV

50Ω

LVPECL

50Ω

100Ω

S

V

S

LVPECL

08280-014

8280-015

8280-016

08280-017

Rev. A | Page 9 of 12

ADCLK948

CLOCK INPUT SELECT (IN_SEL) SETTINGS

A Logic 0 on the IN_SEL pin selects the Input CLK0 and Input

and Input

. A Logic 1 on the IN_SEL pin selects Input CLK1

CLK0

.

CLK1

PCB LAYOUT CONSIDERATIONS

The ADCLK948 buffer is designed for very high speed applications. Consequently, high speed design techniques must be used to achieve the specified performance. It is critically important to use low impedance supply planes for both the negative supply (V

) and the positive supply (VCC) planes as part of a multilayer

EE

board. Providing the lowest inductance return path for switching currents ensures the best possible performance in the target application.

The following references to the GND plane assume that the V power plane is grounded for LVPECL operation. Note that, for ECL operation, the V

power plane becomes the ground plane.

CC

It is also important to adequately bypass the input and output supplies. Place a 1 µF electrolytic bypass capacitor within several inches of each V

power supply pin to the GND plane. In

CC

addition, place multiple high quality 0.001 µF bypass capacitors as close as possible to each of the V

supply pins, and connect

CC

the capacitors to the GND plane with redundant vias. Carefully select high frequency bypass capacitors for minimum inductance and ESR. To improve the effectiveness of the bypass at high frequencies, minimize parasitic layout inductance. Also, avoid discontinuities along input and output transmission lines that can affect jitter performance.

EE

If the return is floated, the device exhibits a 100  cross termination, but the source must then control the common-mode voltage and supply the input bias currents.

There are ESD/clamp diodes between the input pins to prevent the application from developing excessive offsets to the input transistors. ESD diodes are not optimized for best ac performance. When a clamp is required, it is recommended that appropriate external diodes be used.

Exposed Metal Paddle

The exposed metal paddle on the ADCLK948 package is both an electrical connection and a thermal enhancement. For the device to function properly, the paddle must be properly attached to the V

power plane.

EE

When properly mounted, the ADCLK948 also dissipates heat through its exposed paddle. The PCB acts as a heat sink for the ADCLK948. The PCB attachment must provide a good thermal path to a larger heat dissipation area. This requires a grid of vias from the top layer down to the V

power plane (see Figure 18).

EE

The ADCLK948 evaluation board (ADCLK948/PCBZ) provides an example of how to attach the part to the PCB.

VIAS TO VEE POWER

PLANE

In a 50  environment, input and output matching have a significant impact on performance. The buffer provides internal 50 Ω termination resistors for both CLKx and

CLKx

inputs. Normally, the return side is connected to the reference pin that is provided. Carefully bypass the termination potential using ceramic capacitors to prevent undesired aberrations on the input signal due to parasitic inductance in the termination return path. If the inputs are dccoupled to a source, take care to ensure that the pins are within the rated input differential and common-mode ranges.

Figure 18. PCB Land for Attaching Exposed Paddle

08280-018

Rev. A | Page 10 of 12

ADCLK948

V

C

A

C

A

INPUT TERMINATION OPTIONS

CC

VTx

CLKx

V

x

REF

50Ω50Ω

ADCLK948

CONNECT VTxTOVCC.

08280-019

Figure 19. DC-Coupled CML Input Termination

CC

V

x

0.01µF

(OPTIONAL)

50Ω

x

V

T

CLKx

REF

50Ω50Ω

ADCLK948

Figure 20. DC-Coupled LVPECL Input Termination

V

x

REF

V

x

T

CLKx

50Ω50Ω

ADCLK948

CONNECT VTxTOV

REF

x.

08280-021

Figure 21. AC-Coupled Input Termination, Such as LVDS and LEVPECL

V

x

REF

V

x

T

CLKx

50Ω50Ω

ADCLK948

ONNECT VTx, V

BYPASS CAPACITO R FROM V

LTERNATIVELY, VTx, V ONNECTED, GIVING A CLE ANER LAYOUT AND

08280-020

180º PHASE SHIFT.

x, AND CLKx. PLACE A

REF

x TO GROUND.

T

x, AND CLKx CAN BE

REF

08280-022

Figure 22. AC-Coupled Single-Ended Input Termination

V

x

REF

x

V

T

CLKx

ADCLK948

50Ω50Ω

08280-023

Figure 23. DC-Coupled 3.3 V CMOS Input Termination

Rev. A | Page 11 of 12

ADCLK948

OUTLINE DIMENSIONS

INDICATOR

1.00

0.85

0.80

SEATING

PLANE

PIN 1

12° MAX

5.00

BSC SQ

TOP

VIEW

0.80 MAX

0.65 TYP

0.30

0.25

0.18

4.75

BSC SQ

0.20 REF

0.05 MAX

0.02 NOM

0.60 MAX

0.50 BSC

0.50

0.40

0.30

COPLANARITY

0.08

0.60 MAX

25

24

(BOTTOM V IEW)

17

16

32

1

EXPOSED

PAD

8

9

3.50 REF

FOR PROPER CONNECTION OF THE EXPOSED PAD, REFER TO THE PIN CONFIGURATION AND FUNCTION DESCRIPTIONS SECTION OF THIS DATA SHEET.

PIN 1 INDICATOR

2.85

2.70 SQ

2.55

0.20 MIN

COMPLIANT TO JEDEC STANDARDS MO-220-VHHD-2

032807-A

Figure 24. 32-Lead Lead Frame Chip Scale Package [LFCSP_VQ]

5 mm × 5 mm Body, Very Thin Quad

(CP-32-8)

Dimensions shown in millimeters

ORDERING GUIDE

Model1 Temperature Range Package Description Package Option

ADCLK948BCPZ −40°C to +85°C 32-Lead LFCSP_VQ CP-32-8 ADCLK948BCPZ-REEL7 −40°C to +85°C 32-Lead LFCSP_VQ CP-32-8 ADCLK948/PCBZ Evaluation Board

1

Z = RoHS Compliant Part.

Rev. A | Page 12 of 12

Datasheet ADCLK948 Datasheet (ANALOG DEVICES)

FEATURES FEATURES

APPLICATIONS APPLICATIONS

GENERAL DESCRIPTION GENERAL DESCRIPTION

FUNCTIONAL BLOCK DIAGRAM FUNCTIONAL BLOCK DIAGRAM

TABLE OF CONTENTS

REVISION HISTORY

SPECIFICATIONS

ELECTRICAL CHARACTERISTICS

ABSOLUTE MAXIMUM RATINGS

DETERMINING JUNCTION TEMPERATURE

ESD CAUTION

THERMAL PERFORMANCE

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

TYPICAL PERFORMANCE CHARACTERISTICS

FUNCTIONAL DESCRIPTION

CLOCK INPUTS

CLOCK OUTPUTS

CLOCK INPUT SELECT (IN_SEL) SETTINGS

PCB LAYOUT CONSIDERATIONS

Exposed Metal Paddle

INPUT TERMINATION OPTIONS

OUTLINE DIMENSIONS

ORDERING GUIDE