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D1318

D1318. Final presentation Instructor : Yossi Hipsh Students : essam masarwi , hammad abed Pulser. PCB stack , requirements . Use the first layer as a top conductor layer. Isolate the high speed transmission lines.(micro strip).

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D1318

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  1. D1318 • Final presentation • Instructor : Yossi Hipsh • Students : essam masarwi , hammad abed • Pulser

  2. 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.

  3. PCB stack Top layer, used for the high speed lines and the chips assembly. FR4 insulation material, thickness = 10[mils] Power planes Signals, lines… 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. Thickness=34.29[um] Total thickness = 1.7126 [mm] Thickness=254[um]

  4. FR-4 • The 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.

  5. FR – 4 parameters • FR 4 parameters compared with another materials.

  6. Ringing effect - abstract • In 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.

  7. Ringing effect - simulations • Simulations on Hyperlynx :

  8. Ringing effect … sim. results1 • All 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] .

  9. Ringing effect … sim. results2 • MC100EP11 :

  10. Ringing effect … sim. results3 • MC100EP195 :

  11. Ringing effect … sim. results4 • MC100EP05 :

  12. 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] .

  13. 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 ).

  14. Width of Microstripline • We 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.

  15. Electrical scheme

  16. Voltage regulators • Used 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!

  17. 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].

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

  19. 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.

  20. Power limitation • Calculating 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].

  21. Power consumption on PCB • The power consumption is divided to two parts : 1. CMOS block. 2. PECL block. • The CMOS block :

  22. Power consumption on PCB… • The PECL block :

  23. Power consumption on PCB… • K1144ACE: • SN74LVC1T45: • NC7SV157: (*2) • MC74LCX74:

  24. Power consumption on PCB… • MC100EPT20: • MC100EP11: • MC100EP195: • MC100EP05:

  25. 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].

  26. 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].

  27. 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.

  28. Regulators

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