D1318

Final presentationInstructor : Yossi HipshStudents : essam masarwi , hammad abedPulser

PCB stack , requirements • Use the first layer as a top conductor layer.

• Isolate the high speed transmission lines.(micro strip).

• Use the second layer as a ground plane due to the micro strip lines above. (minimize the effect from the power planes and signals)

• keep the high speed lines zone isolated from each other and away from other lines.

PCB stackTop layer, used for the high speed lines and the chips assembly.

Spare layer, in case we need to derivate a high speed line, or any other line or even in case of density in the top layer.

FR4 insulation material, thickness = 10[mils]

Power planes

Signals, lines…

Thickness=254[um]

Thickness=34.29[um]

Total thickness = 1.7126 [mm]

FR-4The most commonly used PCB board material. "FR"

stands for Flame Retardant (resist the spread of fire) and "4" means woven glass reinforced epoxy resin.

Used between each two conductive copper layers, and its thickness is default as 10[mils] = 254[um].

There are several of materials to choose from , but this is the default material used in high frequency boards regarding the material parameters such as : dielectric constant, loss tangent, voltage breakdown …etc.

FR – 4 parametersFR 4 parameters

compared with another materials.

Ringing effect - abstractIn High speed digital circuits, if Driver

impedance is less than the tracer impedance of connected to Receiver, then overshoot and under shoot will occur and as a result signal will be ringing. Up to what level the signal overshoot and under shoot can be bearable. if over shoot signal will be with in the noise margin of the receiver level then what will be effect on the receiver signal due to overshoot.

Ringing effect - simulationsSimulations on Hyperlynx :

Ringing effect … sim. results1All the pecl parts are working with Vpp =

150[mV] (input voltage swing sensitivity) , and from the Hyperlynx simulation results ( shown below) we can see that the Delta (the max voltage swings) is less than 150[mV] .

Ringing effect … sim. results2MC100EP11 :

Ringing effect … sim. results3MC100EP195 :

Ringing effect … sim. results4MC100EP05 :

Micro strip line• High speed lines.• At the end of each line there is a50[ohm]

resistor connected with Vtt.• the width of the Microstrip W fixed in order

to reduce the ringing effect and to have almost smooth rising or falling signal.

• Features :The Microstrip is made of copper with Specific

gravity of 8920 [Kg/m^3] .

Micro strip features t = 3.175[um]

Z0=50[ohm] h=0.254[um] epsilon = 4.3

w = 0.43285 [um]

(The W can be changed by the type of the isolation material, its thickness . Also the the thickness of the Microstrip can change the width ).

Width of MicrostriplineWe got width = 0.432[um] of the

Microstripline in order to keep impedance of a 50[ohm] with the other board and Microstrip parameters .

This result fits with the package dimensions given in the data sheets.

The minimum spacing between two closest pins is 0.65[mm], the connections with the Microstrip is done by pads that the pin can fit in.

Electrical scheme

Voltage regulatorsUsed to keep constant steady voltage at the output.

From the supply voltage pin on the board, we can derivate any voltage level. So we use the REG103-3.3 regulator to get stabilized Vcc voltage, and the REG103-A regulator to get Vtt voltage, and REG103-5 regulator to get stabilized Vdd voltage.

The limitation of the output current, obligate the usage more than one regulator….. So we need to calculate the total power used on the board!

Power on chip• Using the REG103 regulators family we get a

stabilized voltage of Vcc, Vdd and Vtt.

• The REG103-3.3 regulator produces stabilized Vcc.

• The REG103-A regulator produces stabilized Vtt using two resistors in order to get the right voltage ratio in the output.

• The REG103-5 regulator produces stabilized Vdd=5[v].

Power on chip … 2The REG103-3.3/5 regulators :

REG103-3.3 REG103-5

Power on chip … 3•The adjustable regulator using resistor with the right value

 Vout = ( 1+ R1/R2 ) * 1.295

1.3v = 1.295v * ( 1+ R1/R2 ) ratio = R1/R2 = 0.003861 R1 = 100.3861 =~ 100.4k R2 = 100k the capacitor is optional , so we can put a 100 [nF] capacitor.

Power limitationCalculating the current or the power

required on the board leads to the amount of the regulators we need on this board.

The regulators limit current is :

The typical current limit is 700 [mA].

Power consumption on PCBThe power consumption is divided to two

parts :1. CMOS block.2. PECL block.

The CMOS block :sup

2

50[ ]; 3.3[ ];

switching

L dd clk cc dd

dd

P P P

C V f I V

activity factor

f MHz V v

Power consumption on PCB…The PECL block :

2 2sup

sup

( ) ( ) ( ) ( ) ( )

50[ ]

3.3[ ]

( ) ( )

50[ ]

( ) ( )

total i eq dd o l dd

dd

in h tt in l tti

dd cc

o dd oh oh dd ol ol

P nP P C fV mP mCV f

f MHz

V v

V V V VP

P V I

P V V I V V I

n number of theinputsused

m number of theoutputsused

Power consumption on PCB…K1144ACE:

SN74LVC1T45:

NC7SV157: (*2)

MC74LCX74:

18.75[ ] 0.25[ ] 19[ ]P mW mW mW

10.89[ ] 0.0132[ ] 10.9[ ]P mW mW mW

2.97[ ] 7.89[ ] (3.3 0.5 )1.65[ ] 7.9[ ]P uW mW uA uW mW

0.33[ ] 17.96[ ] 0.348[ ]P W mW W

Power consumption on PCB…MC100EPT20:

MC100EP11:

MC100EP195:

MC100EP05:

0.1056[ ] 26.5[ ] 0.1321[ ]P W mW W

0.1452[ ] 18.6[ ] 0.0531[ ] 0.1983[ ]P W uW W W

0.561[ ] 1.61[ ] 0.0265[ ] 0.589[ ]P W mW W W

0.1188[ ] 37.19[ ] 0.0265[ ] 0.1453[ ]P W uW W W

1.4584[ ] ( 0.048[ ])tot R tP watt P mW

Power consumption All the data were taken under worst

conditions in the room temperature from the datasheets.

1. MC100EP05 : Differential and Iee = 29 [mA] , P = 95.7 [mW].

2. MC100EP11 : Differential fanout buffer Iee = 39 [mA] , P = 128.7 [mW].

3. MC100EP195 : ECL Programmable delay chip Iee = 180 [mA] , P = 594 [mW]. (* 2)

4. MC100EPT20 : Differential LVPECL Translator Icc = 28 [mA] , P = 92.4 [mW].

Power consumption …5. MC74LCX74 : CMOS Dual D-Type Flip-Flop

Icc = 10[uA] , P = 33/50 [uW]. 6. NC7SV157 : Multiplexer

Icc = 0.9 [uA] , P = 2.97 [uW]. (* 2)7. SN74LVC1T45 : Single-bit dual-supply bus

transceiver Icc(a) = Icc(b) = 50 [uA] , P = 330 [uW].

8. K1144ACE : 5V Clock Oscillator Icc = 50 [mA] , P = 0.25 [W].

Power summary

All the supply currents approximately reaches 510 [mA], so with the current limitation we need one regulator to stabilize Vcc of 3.3[v] , and other

regulator to stabilize Vdd of 5[v].In order to keep power plane Vtt of 1.3 [v] we also

will need the adjustable feature in the regulator in

order to maintain stabilized 1.3 [v] for the high speed lines.

Regulators