Transcript Final Presentation - High Speed Digital Systems Laboratory

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).
• 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 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]
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.
FR – 4 parameters
 FR 4 parameters
compared with another
materials.
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.
Ringing effect - simulations
 Simulations on Hyperlynx :
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] .
Ringing effect … sim. results2
 MC100EP11 :
Ringing effect … sim. results3
 MC100EP195 :
Ringing effect … sim. results4
 MC100EP05 :
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
(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 ).
w = 0.43285 [um]
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.
Electrical scheme
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!
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 … 2
 The 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 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].
Power consumption on PCB
 The power consumption is divided to two parts :
1. CMOS block.
2. PECL block.
 The CMOS block :
P  Pswitching  Psup 
 CLVdd 2 f clk  I ccVdd
  activity factor
f  50[ MHz ]; Vdd  3.3[v];
Power consumption on PCB…
 The PECL block :
Ptotal  (nPi )  ( Psup )  (Ceq fVdd 2 )  ( mPo )  ( mClVdd 2 f )
f  50[ MHz ]
Vdd  3.3[v]
(Vin  h  Vtt )  (Vin l  Vtt )
50[]
Psup  Vdd I cc
Pi 
Po  (Vdd  Voh ) I oh  (Vdd  Vol ) I ol
n  number of the inputs used
m  number of the outputs used
Power consumption on PCB…
 K1144ACE:
P  18.75[mW ]  0.25[mW ]  19[mW ]
 SN74LVC1T45:
P  10.89[mW ]  0.0132[mW ]  10.9[mW ]
 NC7SV157: (*2)
P  2.97[uW ]  7.89[mW ]  (3.3  0.5uA)1.65[uW ]  7.9[mW ]
 MC74LCX74:
P  0.33[W ]  17.96[mW ]  0.348[W ]
Power consumption on PCB…
 MC100EPT20:
P  0.1056[W ]  26.5[mW ]  0.1321[W ]
 MC100EP11:
P  0.1452[W ]  18.6[uW ]  0.0531[W ]  0.1983[W ]
 MC100EP195:
P  0.561[W ]  1.61[mW ]  0.0265[W ]  0.589[W ]
 MC100EP05:
P  0.1188[W ]  37.19[uW ]  0.0265[W ]  0.1453[W ]
Ptot  1.4584[watt ] ( PRt  0.048[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