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R31UH0005EU0100 Rev.1.0

 Page 2

Jun 3, 2021

8V19N49x Hardware Design Guide

1.  Overview

As indicated, this document provides board-level hardware design guidelines for the 8V19N49x product family. 
The document also recommends power rail handling, loop filter calculation, and input/output termination. A 
general schematic example is shown in 

Figure 1

. A more detailed version is available upon request. 

Figure 1. 8V19N490 Schematic Example

2.  Power Rails

2.1

 Bypass Capacitors

Bypass capacitors are required to filter out the system noise from switching power supplies and switching signal 
interference from other parts of the system. 

Figure 1

 shows examples of bypass capacitors on the schematic. A 

PCB layout example is also available upon request. The type of bypass capacitor will depend on the noise level 
and noise frequencies in the system environment. The synthesizer output driver switching can also cause power 
rail noise. These noises can also interfere with other parts of the circuit or cause spur on other output channels. 

The bypass capacitor values are usually in the range of 0.01uF to 0.1uF; however, other values can be used. 
Typical capacitor sizes are 0603, 0402, or 0201 with low ESR. The dielectric types typically are X5R or X7R. The 
smaller size allows the capacitor to be placed close to the power pin and reduces the trace length. Some capacitor 
vendors such as AVX provide online tools and models to provide the frequency response of the capacitors. 

Figure 2

 t

Figure 5

 show the frequency response of various value capacitors provided by the capacitor supplier 

AVX. The frequency response plot shows that the smaller value capacitor can filter out high frequency noise and a 
larger value capacitor can filter out lower frequency noise. Typical power supply switching frequency can be 

Place on the Top Layer

Layout Note: Place the bypass
capacitors (0201) next to the power
pins

VCO-VC

Place close to
 the DUT

Close to
the pin

VCXO-VC

Place close to DUT  Pins

Place close
toVCXO  Pins 1

Close to the
pins if
possible

VCXO=122.88 MHz
LVPECL

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&/.[Q&/.[,QSXWLQWHUIDFH([DPSOH

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Loop Filter values shown here are
example only. Other values can also
be used. It depends on the system
loop band width requirementn.

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Keep this trace from noisy source

Keep this trace from
noisy source

VDD_LCF(Clean)

LVPECL Termination Example

There are many way to
terminate LVPECL driver

There are many way to
terminate LVPECL driver

VDD1

VDD_SYNC

VDD_QCLKB

VDD_QREFB

VDD_QCLKD

VDD_QREFD

VDD_QCLKE

VDD_SPI

VDD_CP2

VDD_LCV

VDD_QREFC

VDD_QCLKC

VDD_LCF

VDD_QCLKA

VDD_QREFA

VDD3

VCC_VCXO

VCC_VCXO

VDD

VREG_3.3V

VDD_SPI

LFV

SDAT

nINT

nCS
SCLK

LOCK

LFV

Q_VCXO

nQ_VCXO

Q_VCXO

nQ_VCXO

R16

2.8K, 1%

Zo = 50

R51
50

U5

VCXO_5mmx7mm_6pin_long_pad

VCONT

1

OE

2

GND

3

Q

4

nQ

5

VCC

6

R18
100

R7

1k

C3

100p

C5
0.1u

C28
0.1u

C19

100p

C13
0.1u

TP1

C9

100p

C17

High Impedance

+

-

R22
33k

R12

10K

C14

C4
0.1u

C29
0.1u

R15
10K

High Impedance Input

+

-

Zo = 50

C15

C32

0.1u

C31

33p

U1

IDT8V19N490

nQCLKB0

A1

QCLKB0

A2

VDD_QCLKB

A3

nQREF_B0

A4

QREF_B0

A5

nQCLK_B1

B1

QCLKB1

B2

VDD_QREFB

B3

nQREF_B1

B4

QREF_B1

B5

VDD_CP

B6

nOSC

B7

VDD_OSC

B8

QCLK_A1

B9

nQCLK_A1

B10

LFV

A6

OSC

A7

GND_A8

A8

QCLK_A0

A9

nQCLKA0

A10

GND_C1

C1

GND_C2

C2

GND_C3

C3

VDD_QREFD

C4

SELSV

C5

GND_C6

C6

X1

C7

nINT

C8

QCLK_A2

C9

nQCLK_A2

C10

nQCLK_D

D1

QCLK_D

D2

VDD_CLLKD

D3

nQREF_D

D4

QREF_D

D5

GND_D6

D6

X2

D7

GND_D8

D8

VDD_QREFA

D9

VDD_CLKA

D10

GND_E1

E1

GND_E2

E2

VCC_SPI

E3

nCS

E4

SCLK

E5

GND_E6

E6

GND_E7

E7

SDAT

E8

QREF_A2

E9

nQREF_A2

E10

nQREF_C0

F1

QREF_C0

F2

EXT_SYS

F3

CLK3

F4

CLK2

F5

CLK1

F6

CLK0

F7

RES_CAL

F8

QREF_A1

F9

nQREF_A1

F10

nQREF_C1

G1

QREF_C1

G2

VDD_INP

G3

nQCLK3

G4

nQCLK2

G5

nQCLK1

G6

nCLK0

G7

LOCK

G8

QREF_A0

G9

nQREF_A0

G10

VDD_CLKC

H1

VDD_QREF_C

H2

GND_H3

H3

GND_H4

H4

GND_H5

H5

GND_H6

H6

VDD_SYNC

H7

GND_H8

H8

GND_H9

H9

GND_H10

H10

nQCLK_C0

J1

QCLLK_C0

J2

GND_J3

J3

VDD_LCV

J4

CR0

J5

GND_J6

J6

GND_J7

J7

GND_J8

J8

QCLK_E1

J9

nQCLK_E1

J10

nQCLK_C1

K1

QCLK_C1

K2

GND_K3

K3

VDD_LCF

K4

LFFR

K5

LFF

K6

VDD_CPF

K7

VDD_QCLKE

K8

QCLK_E0

K9

nQCLK_E0

K10

Zo

R8

10K

C11

J1

R10
5.1K

C7
100p

C16
0.1u

R14

10K

Zo

R24
np (49.9)

C38

0.1uF

C8
0.1u

C22
0.1u

JP1

LVDS Driver

R11

5.1K

R53
50

C12
0.1u

C24
0.1u

C37
1u

C35
4.7n

C30

0.1u

C23

0.1u

C39

100pF

C27

100p

R5
100

C10
0.1u

C2
0.1u

R13

2 x Zo

C18

0.1u

R19
np (49.9)

C6
0.1u

Zo = 50

C20

0.1u

R20

51k

R9

100

C26
4.7u

C21
0.1u

Zo = 50

J2

C34
27n

C1
0.1u

R52
50

QREFD0_N

QCLKE0_N

QCLKE1_P

QCLKB0_N

QCLKB1_P

LFF

CLK1

QREFA1_N

QCLKA2_P

QREFA2_N
QREFA2_P

QREFA0_P

QREFA0_N

QCLKE1_N

QCLKE0_P

QREFA1_P

QCLKC0_N

QCLKA0_P

QCLKA0_N

QCLKC0_P

QCLKA1_N
QCLKA1_P

QCLKA2_N

nCLK2

CLK2

CLK3

nCLK3

QCLKB1_N

QCLKB0_P

QCLKD0_N
QCLKD0_P

QREFB1_N

QREFB1_P

QREFB0_N

QREFB0_P

QREFD0_P

QREFC0_N
QREFC0_P

nCLK1

CLK0

QREFC1_N
QREFC1_P

LFFR

MCLK_P

MCLK_N

RES_CAL

EXT_SYS

VC
OE

QCLKx

nQCLKx

QCLKx

nQCLKx

QCLKA0

nQCLKA0

nCLK0

Содержание 8V19N49 Series

Страница 1: ...5 3 2 3rd Order Loop Filter 6 3 3 Loop Filter Calculation Examples 7 3 3 1 Loop Filter for VCXO PLL 7 3 3 2 Loop Filter for VCO PLL 10 4 Input Output Interface 11 4 1 Input Termination for Reference Clock Input 11 4 2 Output Terminations for QCLK and QREF Drivers 13 4 2 1 LVPECL Type Driver Terminations 13 4 2 2 LVDS Type Driver Terminations 15 4 2 3 DC Coupling Interface for QREF Driver 15 5 Sche...

Страница 2: ...U RKP ODE HTXLSPHQW PRQLWRULQJ H J SKDVH QRLVH PHDVXUHPHQW Keep this trace from noisy source Keep this trace from noisy source VDD_LCF Clean LVPECL Termination Example There are many way to terminate LVPECL driver There are many way to terminate LVPECL driver VDD1 VDD_SYNC VDD_QCLKB VDD_QREFB VDD_QCLKD VDD_QREFD VDD_QCLKE VDD_SPI VDD_CP2 VDD_LCV VDD_QREFC VDD_QCLKC VDD_LCF VDD_QCLKA VDD_QREFA VDD3...

Страница 3: ...y and high frequency noise To minimize ESR between power pins and the bypass capacitors Renesas suggests at least one bypass cap per power pin and to place these capacitors as close as possible to the power pins Thicker trace widths between the bypass capacitor and power pin can also help reduce the ESR Figure 2 Example of a 100nF Bypass Capacitor Frequency Response Figure 3 Example of a 10nF Bypa...

Страница 4: ...0100 Rev 1 0 Page 4 Jun 3 2021 8V19N49x Hardware Design Guide Figure 4 Example of Larger Value 4 7uF Bypass Capacitor Frequency Response Figure 5 Example of Smaller Value 100pF Bypass Capacitor Frequency Response ...

Страница 5: ...e For the VDDO output supplies to reduce output frequency interference the power rails between the output banks that operate at different output frequencies can be isolated using separate LDOs or using 1 to 2 ohm resistors if they share the same power source Additional smaller value capacitors e g 100pF in parallel with the existing 0 1uF near the power pins can provide additional higher frequency...

Страница 6: ...fc fz recommend α to be greater than 3 fz is frequency at zero 4 Calculate Cp Where fp is frequency at pole β is ratio between frequency at pole and loop bandwidth β fp fc recommend β greater than 3 5 Verify maximum Phase Margin PM Where The PM should be greater than 50 degrees 3 2 3rd Order Loop Filter This section provides design guidelines for a 3rd order loop filter A typical 3rd order loop fi...

Страница 7: ...tool will provide the component values Rs Cs and Cp as result The tool will also calculate maximum phase margin for verification The 3rd order loop filter R3 and C3 are also calculated using the actual 2nd order loop filter components values 3 3 Loop Filter Calculation Examples 3 3 1 Loop Filter for VCXO PLL 3 3 1 1 Second Order Loop Filter for the VCXO PLL This section provides calculation exampl...

Страница 8: ...und or derived from the VCXO datasheet The VCO gain can also be measured from lab experiments In this example we use Kvco 10kHz V The 8V19N490 charge pump current can be programmed from 50uA to 1 6mA In this example assume the charge pump current is programmed to Icp 800uA Cs can be calculated from the following equation For α 8 Cs is calculated to be 0 99uF Cs greater than this value can be used ...

Страница 9: ...e calculated using the following equation 2 Pick γ 4 in this example C3 is calculated to be 4 37nF A closest standard capacitor value can be used Table 2 shows some VCXO PLL Loop Filter examples for different VCXO frequencies Other values can also be used to meet other specific conditions and requirements Table 2 Loop Filter Examples VCXO Frequency 1 122 88MHz 30 72MHz VCXO Made Model Examples Eps...

Страница 10: ...l VCO 2nd order loop filter works in conjunction with the internal circuitries A traditional loop filter calculation method may not be accurate After simulation and actual experiment an example of external two pole loop filter value is provided in Table 3 R3 51k Ohm 1 8k Ohm C3 4 7nF 33nF 1 Other VCXO frequencies can also be used with proper loop filter and parameter setting Below are examples of ...

Страница 11: ...nput driven by a differential driver with AC coupling This section discusses only few examples other termination topologies can also be used if desired Figure 13 Input Termination Example 8V19N490 Reference Clock Input CLK nCLK Driven by a 3 3V LVPECL Driver Table 3 VCO PLL 2nd Order Loop Filter Recommendation VCXO used in the 1st PLL 122 88MHz 30 72MHz PDF Phase detector input frequency with doub...

Страница 12: ...k Input CLK nCLK AC Coupling Termination Example 1 Figure 16 8V19N490 Reference Clock Input CLK nCLK AC Coupling Termination Example 2 VCC 3 3V Zo 50 Zo 50 LVDS Driv er VCC 3 3V R1 100 Clock Input CLK nCLK VCC 3 3V Clock Input CLK nCLK R4 10K R2 10K R3 5 1K R1 5 1K VCC 3 3V C1 C2 Differential Signal Zo Zo R5 2 x Zo VCC 3 3V Clock Input CLK nCLK C1 C2 Differential Signal Zo Zo R5 Zo R4 10K R3 5 1K ...

Страница 13: ...esistor for the DC current path in order for the output to switch A standard LVPECL driver termination is displayed in Figure 17 There are many ways to terminate the LVEPCL driver Figure 18 to Figure 21 show several examples of LVPECL style driver termination Figure 17 Standard LVEPCL 750mV Driver Termination Figure 18 LVPECL 750mV Termination Example 1 VCC 3 3V High Input Impedance CLK nCLK R4 50...

Страница 14: ...PECL Driver AC Coupling Termination for the Receiver with Built in Termination VCC 3 3V R4 50 R2 50 Zo 50 Zo 50 VCC 3 3V LVPECL Driv er R2 50 C1 0 1uF optional High Input Impedance CLK nCLK 50 Ohm 50 Ohm 8V79S680 IN nIN VT VCC 3 3V Zo 50 Zo 50 VCC 3 3V LVPECL Driv er R2 120 to 240 R1 120 to 240 Zo 50 Zo 50 VCC 3 3V LVPECL Driv er R2 120 to 240 R1 120 to 240 50 Ohm 50 Ohm 8V79S680 IN nIN VT VCC 3 3...

Страница 15: ...e not quite same as standard LVPECL or LVDS The amplitude can be programmed to different amplitude levels 250mV 500mV 750mV and 1000mV The DC offset is about 2V for both LVPECL and LVDS driver 2V DC offset is close the standard LVPECL signal however 8V19N490 LVDS DC offset is about 2V which is not standard In some applications the receiver requires lower DC offset level with DC coupling interface ...

Страница 16: ...e s ig n file U N N A M E D 0 TL N D e s ig n e r M in g L im H y p e rL y n x V 7 7 D a te Th u rs d a y S e p 1 1 2 0 0 8 Tim e 1 1 5 0 3 9 C u rs o r 1 V o lta g e 1 3 9 1 6 V Tim e 2 4 9 1 n s C u rs o r 2 V o lta g e 8 5 5 4 m V Tim e 6 9 8 2 n s D e lta V o lta g e 5 3 6 1 m V D e lta Tim e 4 4 9 1 n s S h o w L a te s t W a ve fo rm Y E S 4 0 0 0 6 0 0 0 8 0 0 0 1 0 0 0 0 1 2 0 0 0 1 4 0 0 ...

Страница 17: ...n for the non built in is not feasible The DC coupling interface example to shift down the DC offset level is displayed in Figure 27 Figure 26 Receiver with Built in 100 ohm Figure 27 DC Coupling Example for Receiver with Built in Termination Figure 28 Simulation Waveform at the Receiver 50 Ohm R4 100 50 Ohm 8V19N490 LVEPCL 750mV 3 3V R1 43 100 R2 43 R3 100 Receiver w ith Built in 100 Ohm across ...

Страница 18: ...d to shift close to this level Figure 29 Interface to Receiver with Built in Termination and Built in DC Bias The value of the component is shown in Table 4 VDDO 3 3V The QREF output is set to LVPECL style driver and the amplitude is set to 750mV Figure 30 Simulation Waveform at the Receiver Table 4 Component Values Component References Component Values R1 100 Ohm R2 100 Ohm R3 100 Ohm R4 100 Ohm ...

Страница 19: ...021 8V19N49x Hardware Design Guide 5 Schematic Diagrams The following schematic diagrams are available from request 8V19N490 EVB schematic 8V19N490 EVB board layout 6 Revision History Revision Date Description 1 0 Jun 3 2021 Initial release ...

Страница 20: ...re intended for developers skilled in the art designing with Renesas products You are solely responsible for 1 selecting the appropriate products for your application 2 designing validating and testing your application and 3 ensuring your application meets applicable standards and any other safety security or other requirements These resources are subject to change without notice Renesas grants yo...

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