AN97090 Oscillators 8-bit microcontrollers Application Note
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Oscillators 8-bit microcontrollers
AN97090
Oscillators 8-bit microcontrollers
Application Note AN97090
Abstract "Going digital" "programmable architectures" product strategies today. However digital system will without clock oscillator circuit "oscillation" very analogue phenomena that still need additional clarification. Quite some theory some practice this subject based microcontrollers covered this application note.
Philips Electronics N.V. 2001 rights reserved. Reproduction whole part prohibited without prior written consent copyright owner. information presented this document does form part quotation contract, believed accurate reliable changed without notice. liability will accepted publisher consequence use. Publication thereof does convey imply license under patent- other industrial intellectual property rights.
Oscillators 8-bit microcontrollers
Application Note AN97090
Oscillators 8-bit microcontrollers
AN97090
Authors: Andre Pauptit Rosink Philips Semiconductors Systems Laboratory Eindhoven, Netherlands
Keywords: crystals,overtone mode,transconductance,Pierce, fundamental mode,87C750,ceramic resonator.
Number pages:
Date: 97-12-11 final draft),
editing appendix: 2001-07-06 W.S.
Oscillators 8-bit microcontrollers
Application Note AN97090
Summary Basically this application note addition AN96103 "Xtal oscillators 8-bit microcontrollers" handles with harmonic Xtal resonation ceramic resonators. Oscillator theory, component value calculations, parameter measurements part this application note, application info with component type numbers another part.
Honourable mention
Rosink
Rosink retired this year after contributing more than years Systems Eindhoven. long experience with many analogue circuits, like: oscillators many variations, phase locked loops, etc. This, combined with knowledge CMOS-technology CMOS-digital families, makes ideal resource subjects this application note. Most research documenting this application note done Wim. microcontroller sales support group grateful high level contribution oscillator subject convinced that will useful those that want need more background oscillation issue relation microcontrollers.
Special thanks special thanks given muRata* their representives Germany Netherlands giving support developing this application note.
(*TOYAMA MURATA MANUFACTURING CO., LTD)
Oscillators 8-bit microcontrollers
CONTENTS
Application Note AN97090
INTRODUCTION case. subjects OSCILLATION CONDITION CIRCUIT PARAMETERS. crystal equivalent circuit Equivalent circuit Pierce oscillator. Design considerations Pierce oscillator. Drive level power dissipation Oscillator start-up time. Practical hints TRANSCONDUCTANCE MEASUREMENT XTAL CIRCUIT PARAMETERS. Measuring method. Measuring results. CRYSTAL OVERTONE OSCILLATOR Forcing overtone mode frequency dependent damping. Connection inductive trap filter output. Inductive filter input. Drive level. Conclusion. MURATA CERAMIC RESONATORS Resonator types 8400 8051 microcontrollers. Resonator types P87CL884 6.2.1 types 6.2.2 12.20 resonators. 6.2.3 3.58 resonators. Resonator types P80C54/P87C51RA+ REFERENCES APPENDIX.24
Oscillators 8-bit microcontrollers
INTRODUCTION
Application Note AN97090
Most microcontrollers include internal circuitry generate required clock pulses processor functions. frequency rate these clock pulses selected some external components. less demanding applications, simple circuitry even circuit used frequency. However, when higher frequency stability required, oscillation circuit with ceramic resonator best stability, circuit with external crystal should used.
case
Crystals available frequencies from 1MHz 100MHz higher. higher clock frequencies, e.g. above MHz, resonators crystals mostly will used third fifth overtone oscillation mode. This application note basically build around oscillator case with microcontroller that runs higher frequencies also, there opportunity study behaviour third overtone oscillation. Fig.1 below shows this case, typical circuit clock oscillator with third overtone crystal P87C750 microcontroller.
Vcc=5V
C750
Used Crystal: Third overtone, Philips 39.130 MHz, 02370991
Fig.1 Pierce oscillator circuit
crystal connected directly input output microcontroller inverting gate. capacitors connected from these points ground perform required load capacitance crystal. most applications, values these capacitors between 30pF both about equal C1<C2. With C1>C2 feedback gain will small, reducing gate input voltage.
subjects
oscillation conditions given crystal parameters, external capacitors current gain transconductance inverter. next sections will describe following subjects: calculate oscillation condition measure crystal parameters measure oscillator gate circuit parameters
Oscillators 8-bit microcontrollers
OSCILLATION CONDITION CIRCUIT PARAMETERS. crystal equivalent circuit
Application Note AN97090
resonant point, equivalent circuit crystal resonator behaves like circuit Fig.2, hence series connection parallel with capacitance example shows third overtone crystal with main modes resonance, 13MHz, fundamental mode, third overtone mode MHz. circuit impedance given equation below:
XTAL
Fig.2 Equivalent crystal circuit.
Eq.1
values equivalent circuit components were measured with impedance/phase analyser HP4194 both resonance modes, explained section results given section 4.2:
Crystal electrical data crystal:
Fundamental mode: Third overtone: Fs0=13.055MHz Fs3rd=39.13MHz Rs=57E, Ca=12fF, L1=11.9mH, Cb=2.8pF Rs=30E, Ca=1fF, L1=16.8mH, Cb=3.3pF
both modes, with value Cb>>Ca, "series resonance" frequency with given will very close value "parallel resonance" frequency, given Ca,Cb series, because CaCb/(Ca+Cb) close Below shows that negative resistance added circuit compensate damping oscillation using transconductance gain inverter start oscillator.
Equivalent circuit Pierce oscillator.
Iout=
Iout=
Fig.3a. Pierce scillato circuit
Fig.3b. quivalent circuit
Fig. 3a+b shows used Pierce oscillator circuit with equivalent circuit diagram, which crystal replaced L1,Ca,Rs inverter replaced output impedance output current from transconductance gain: Iout= gm.V1. bias resistance force gate input threshold level provide starting most µcontroller-types feedback transistor already integrated semiconductor resistor parallel inverting gate.
Oscillators 8-bit microcontrollers
Application Note AN97090
such Pierce oscillator, crystal should operated "parallel resonance" mode with parallel components C1/C2 series. Therefore this circuit also called positive reactance oscillator, because branch L1/Ca/Rs should inductive. resonance, total impedance high, with degree phase shift between gate input output signal. circuit will oscillate, negative reactance transconductance current gain just compensates damping resistive elements very convenient also rather easy prove oscillation condition transfer these elements series with means power dissipation rule, saying that elements gm.V1 replaceable resistor series with this gives same dissipation damping circuit. Then oscillation condition true, total value resistive elements, including damping crystal less than zero. After transferring resistive elements into series branch, simplified resonance calculation model fig. used.
R'gm
Cload Cpar. Cpar= parasitic capacitance across gate. Cload C1C2 C1,C2 include parasitics input output. resonance with Co>>Ca, o=1/v(L1.Ca) +R'p +R'o +R'gm.
Fig.4 Resonance calculation model
this figure, total parallel capacitance, including load capacitance Cload formed capacitance's series parasitic capacitance's input output parallel with gate. value given +R'o +R'gm. Assuming that resonance, ICo, then follows PRp= P'R'p (Vx) .R'p with (Vx). o.Co follows: (Vx)
.Eq.2
output impedance follows with PR'o: R'o, with Vx.C1/(C1+C2) IRo= Vx.o.Co follows: x.C1 /(C1+C2)
.Eq.3
Transferring gm.V1 R'gm means, with (gm.V1) PR'gm -gm.V1.V2 R'gm with V1=Vx C2/(C1+C2), Vx.C1/(C1+C2) IRt= follows: -gm.Vx .C1.C2./ (C1+C2) R'gm.
Oscillators 8-bit microcontrollers
Application Note AN97090
.Eq.4
C1C2 .Eq.5
Combining these equations, obtain total series resistance:
circuit will oscillate, value zero negative. minimum value should
C1C2 C1C2
.Eq.6
first products this equation reduced minimum value with This means, that easiest oscillation, both load capacitance's should equal. this case find:
gm.min
.Eq.7
last equation minimum required value confirms quite well with values derived publications mentioned references determine gm-min worst case design, should noted, that value vary with drive level, much higher than specified value from device data drive level during start-up. also section 2.6. Ref.4. from Rusznyak also derives maximum value transconductance above which oscillation possible. most cases this value much higher than minimum value neglected. However frequency crystals, operating around kHz, might influence oscillation condition. equation this maximum allowable value transconductance with Cpar, fig.(3+4)
gm.max
C1C2 .(Rusznyak).Eq.7a
Design considerations Pierce oscillator.
Based upon equation first estimation made about oscillation condition certain combination inverter gate crystal. example take third overtone crystal mentioned example above gate P87C750 microcontroller which measured data given section 4.2, crystal
crystal electrical data:
Fundamental mode: Third overtone: Fs0=13.055MHz Fs3rd=39.13MHz Rs=57E, Ca=12fF, L1=11.9mH, Cb=2.8pF Rs=30E, Ca=1fF, L1=16.8mH, Cb=3.3pF
From measurements section inverter gate follows: Transconductance mA/V (typical, worst case!), output impedance 3000 Bias resistance Then with Cload+Cpar 10pF with eq.7 minimum value should Fundamental: o.Co= 0.000820 gm-min 0.000153 0.000004 0.00033= 0.000487
Oscillators 8-bit microcontrollers
Application Note AN97090
Third overtone: 0.00246 gm-min 0.000725 0.000004 0.00033= 0.001059 Hence both modes, with gm-min= 0.002 circuit will oscillate. suppress wanted fundamental mode, special measures required, using inductive trap filter using extra damping across circuit. This subject will described more detail section From Eq.7 derived, that with given with Rp>> maximum value parallel capacitance crystal inversely proportional with root value
.Eq.8
crystal above Fs=39MHz, R0=3000, gm=1mA/V, find With Rs=100, with allowed value 16.7pF. From values shown conclusion will that 30MHz overtone crystal, value load capacitance's rather limited. With being below 10pF, proper values also below 10pF.
Drive level power dissipation
most crystals maximum drive level specified, e.g. <5mW. drive level calculated from power dissipation series resistance crystal resonance, power dissipation .Rs., with IRt= .o.Co effective voltage across crystal. resonance voltages across crystal points opposite polarity maximum peak peak value both about supply voltage Vcc. Hence effective value across Vcc/v2 Vx=3.5V. find (3.5 .Rs, Drive level
.Eq.9.
With crystal from before fs=39MHz, Co=10pF Rs=30, get: 0.0022 Watt. applications requiring high stability, databooks advise drive levels between Drive levels above seriously affect frequency stability quartz crystal. Resonators much less sensitive overdrive, they used higher drive levels. Special attention should taken with crystals, operating overtone mode high frequencies above 10MHz, because square influence resonance frequency Eq.9. E.g. A216 crystal, section 4.2, nr.10. with 35.25MHz, 20pF, 16.6 this case, load should reduced lower value, e.g. 10pF. Then, 4.1mW.
Oscillator start-up time
With fundamental resonance model shown Fig.4, oscillation start-up time calculated assuming initial noise current through circuit VCo= t=0.
Oscillators 8-bit microcontrollers
Application Note AN97090
Then using Laplace transformation, voltage across derived:
with 1/(L1Ca) .Eq.10
assure, that voltage increases, should negative, with sufficient high value Then, each increases with factor e=2.72. Hence, increase from initial noise level e.g. logic level 2.5V, start will take: Tstart-up= ln(2.5/1e-6) sec. .Eq.11 value given Eq.5. Neglecting part 1/Rp with 4/Rp 1/Ro C1=C2, follows:
Some examples:
.Eq.12
Crystal nr.7 Fs=39MHz, Co=10pF, gm=0.002mA/V, Ro=3000, Rs=30, L1=16.8mH.: Rt=30 1/0.000024(1/3000- 0.002) -39. Hence Rt/2L 1160.sec start time from 2.5V amounts Tstartup= 1/1160 0.013 sec. Crystal nr.4. 32kHz, 20pF, L1=9.3kH, Rs=15 (from data) this type, should reduced keep value below gm.max given Eq.7a. From this equation gmmax= 1/Rs (C1/C0) 100µS. Further gmmin= Rs.40 15e3.4 1µS. Assume Ro=3.8M, given micro controller data handbook, IC20. Hence, 15e3 (1/64e-12)(1/3.8e6 -15e-6) 15e3 4100 234e3 215e3 Rt/2L=11.6 start-up time Tstartup= 1/11.6 sec.
Practical hints
Testing probe gate input side, this will disturb biasing level. higher frequencies, load capacitance's need lower limit drive level, e.g. overtone crystal, with Rs=30, C1=C2 With C1<C2, circuits power consumption will reduced. Higher input signal means higher dV/dT shorter operation threshold region. most micro controllers, signal input oscillator gate also used internal clock. Therefore take C1<C2 assure that input level sufficient high. third fifth overtone crystal, tank filter suppress fundamental mode. high frequency ceramic resonators operating overtone mode, general filter required, these components have build measures suppress unwanted frequencies. When calculating minimum required value transconductance start-up, take care that drive level dependency, value serial resistance crystal start-up much higher, from higher times specified measured value operating condition.
Oscillators 8-bit microcontrollers
TRANSCONDUCTANCE MEASUREMENT
Application Note AN97090
XTAL oscillators, described this note type Pierce operate with internal inverter stage microcontroller. calculations, such gate amplifier replaced simulation circuit with simplified diagrams Fig.5. current source equivalent, output current defined transconductance gate input voltage Vin. CMOS gate used here input resistance neglected. most cases, output impedance much higher than output load resistance output seen real current source with Vin. voltage source equivalent, current source replaced voltage source gm.Vin.Ro. Again, with Ro>>Rload, output behaves current source, gm.Vin.
gm.Vin Current source Voltage source
Vout
gm.Vin.Ro
Vout
Fig. Gate equivalent circuit
Fig.6 shows standard test measure transconductance CMOS gate, used CMOS products like HCU04. With fixed input voltage 100kHz, Vout measured then transconductance calculated
560k
Vout .Eq.13. Vinp Vinp
470nF
100µF
Vinp
100E
Voutp
Fig.6 Test circuit transconductance
Test results with some microcontroller devices calculated values transconductance listed following table.
Oscillators 8-bit microcontrollers
TABLE Vinp=400mV 100kHz, 100.
Vcc=5V Device: P87C750, EBFFA,16 P87C750, PBFFA,40 EP87C750-4N P87C750 EBPN S87C751 4F24 P87C748 EBFFA P87C750 PBFFA Vout mA/V 5.25 3.25 Vc=4V Vout mA/V 4.25 3.75 4.25 3.75 Vcc=3V Vout.
Application Note AN97090
mA/V
table shows, that Vcc=5V, transconductance amounts 5mA/V. Vcc=3V, minimum value gm=1.5 mA/V found, calculation, gm-min= mA/V. value output impedance influence effective value R0>> Rload. Therefore value also measured with test circuit Fig.7.
200mV
Vout
Fig.7 Test circuit output impedance
signal supplied output gate series resistance decoupling capacitor 1µF. gate input kept quiet capacitor ground prevent input signal passing from output through With follows:
Vout 1000 .Eq.14 Vout Vout
With 200mV 100kHz, following values were found:
Oscillators 8-bit microcontrollers
TABLE Gate output impedance, Vin=
P87C750, EBFFA,16 P87C750, PBFFA,40 EP87C750-4N P87C750 EBPN S87C751 4F24 P87C748 EBFFA P87C750 PBFFA Vout mVolt 3348 3545 4000 3000 6142 3760 4555
Application Note AN97090
Note that between kOhm, which sufficient higher than value R1=100 fig.6. have influence transconductance value.
Oscillators 8-bit microcontrollers
XTAL CIRCUIT PARAMETERS Measuring method
Application Note AN97090
crystals mentioned this report tested 4194A impedance/phase analyser determine equivalent electrical data crystal, required simulation oscillator circuit. carry measurements, following short list test adjustment procedures instruments knobs assistance start first measurement. object impedance/phase curve function frequency around resonance points from this derive main equivalent circuit parameters such point. Used instrument: 4194A Impedance/gain-phase analyser. equipment should turned fifteen minutes before ensure warming example, measurement done with 35.25 overtone crystal. underlined items settings means pressing mentioned button item block. Check IGPB connection with plotter (Here thinkjet) Check plotting mode: Menu more menus HPIB define talk only return. menu Function impedance menu sweep sweep sweep parameter start (e.g.) stop 40MHz level Volt. menu compen zeroshrt zero open shrtofson openofson. insert crystal. Then with sweep mode repeat, start testing. menu display rect (sub) menu scale auto scale scale auto scale unit grtcl
display should show curve from MHz. Then decrease frequency range around resonance point. parameter start stop start 35.2 stop 35.4 Repeat auto scale step menu 2/3. further decrease range around Fs=35.25 start 35.24 stop 35.26 MHz. Note: before plotting, pre-set frequency range range units easier read out. Plot both graphs copy Calculating equivalent circuit parameters around resonance point: Menu more menus eqvckt calc para (plot) copy display. Both curves values equivalent circuit components plotted page, shown appendix different crystals resonators. Table3 next section gives survey measured data values these devices.
Oscillators 8-bit microcontrollers
Application Note AN97090
Measuring results.
Type Murata, CST12.0 Murata, CSA12MTZ Murata, CSA16MXZ XTAL, 32.768 XTAL, MHz, XTAL, XTAL 39.13 overtone spurious spurious Murata, CSA36 00MXZ Murata, CSA39.00MXZ overtone spurious XTAL, IQD, A216 35.25 overtone XTAL+ 10pF//. spurious Mode Fund. Fund. Fund. Fund. Fund. Fund. Fundam. overt 3rd, spur. 3rd, 2spur Fund. overt. 3rd, spur. Fund.? overt. 3rd, spur. Fund.+3rd Fund. overt. overt 3rd, spur. Fs=1/LC 32.78 13.06 39.13 39.24 39.38 36.0 36.4 11.05 39.00 39.3 11.77 35.256MHz 35.251MHz 35.32MHz 45.6 47.3 8.47 13.05mH 11.9 16.8 36.6 -259 1.64 -209 1.39 22.1 29.3 29.2 4.17 4.04 2.54 20.8 7.58 12.5 0.98 0.45 0.144fF -75.3 11.7 -80.0 11.8 8.28 0.695 0.697 0.181 6.10 5.28 11.1 -8.20 10.9 57.8 29.6 -17.4 -13.9 69.1 69.6 40.3 27.0 13.1 1.28 4.85 2.14 2.86 3.24 2.81 2.79 -8.70 3.69 -9.81 2.78 1.78 2.19 12.24pF 2.03
TABLE Equivalent circuit parameters some XTALS, also appendix
This table includes several test results 35MHz, third overtone XTAL from (type A216) also used clock oscillator circuit 87C750 microcontroller. After some analysis XTAL equivalent circuit parameters available XTAL samples typical gain output characteristics microcontrolller gate, next chapter this application note describes several circuit proposals P87C750 circuit obtain optimum start action prevent oscillation undesirable fundamental mode.
Oscillators 8-bit microcontrollers
CRYSTAL OVERTONE OSCILLATOR
Application Note AN97090
This chapter gives some application proposals overtone XTAL circuits, used clock generation section microcontrollers these applications, precautions should taken prevent oscillation fundamental mode force overtone mode. Three proposals given: Higher damping fundamental mode applying ohmic resistor across gate. Connection inductor between gate output ground trap fundamental mode Connection such inductor between gate input ground. clock frequencies excess MHz, standard XTALs preferred available overtone oscillation mode should used. Following some circuit possibilities such XTAL clock generation P87C750 microcontroller given. circuit diagram oscillator with internal gate micro givens Fig.
Vcc=5V
Fig.8.
C750
circuit above, together with overtone XTAL, only oscillates fundamental mode. Hence measures required force circuit into third overtone mode. equivalent XTAL circuit data, shown Fig.9b, listed below fundamental mode third overtone.
XTAL 39.13 overtone
Mode First Third Third (Spur.) Fseries 13.05 39.13 39.24 11.9 16.4 33.6 12.5 0.45 57.6 30.3 2.84 3.34
this XTAL, ratio Rs_1/Rs_3 57.6 30.3 1.9. A216, Rs_1/Rs_3= chapter Based upon these results XTAL parameters, next section will discuss results some practical tests with XTALs used with microcontroller circuit.
Oscillators 8-bit microcontrollers
Application Note AN97090
Forcing overtone mode frequency dependent damping.
This circuit uses value resistance between gate output input. Fig.2a
Cg=4.7pF, C2=15pF, Re=3900
Fig.9a
Fig.9b
Forcing third overtone mode achieved connecting ohmic resistor parallel with XTAL. Fig. shows equivalent XTAL circuit diagram with connected total parallel capacitance XTAL, CgC2/(Cg+C2). This circuit will oscillate either fundamental mode overtone, gate amplifier compensates damping resistors external damping influence much higher fundamental mode, which shown replacing into series loop L1/C1/Rs Re_s. This delivers
This equation shows that times lower damping value into series resonance circuit requested overtone frequency. With above specified XTAL gate microcontroller P87C750 (PBFFA), this circuit been tested proved oscillate third overtone conditions with following circuit values: XTAL: 39.13MHz, Cg=4.7pF, C2=15pF, 3900 Ohm.
Connection inductive trap filter output.
Fig.10
Cg=10 C2=27 microH. 4700
this circuit, fundamental mode suppressed connecting inductance output gate amplifier. Together with part capacitance output, this inductor will perform high impedance parallel circuit overtone frequency inductive impedance fundamental one. capacitance decoupling capacitor gate bias voltage, sourced (internal) resistor With Lp=1.5 microH, resonance occurs with 11pF. Hence, value should >11pF. practical test, correct overtone oscillation obtained with following circuit values: microH. 4700
Oscillators 8-bit microcontrollers
Application Note AN97090
Inductive filter input.
Fig.11
microH. 4700
Here inductive trap filter connected input side. Optimum circuit values this case were: Cg=10pF, C2=10pF, L1=1.5microH C3=4700pF. Hence 39MHz capacitance fully tuned only capacitance left input input stray capacitance, order 5pF. Note. circuit values given above optimal values applied XTAL specified above typical microcontroller oscillator gate, with measured transconductance, Vcc=5V., around mA/V. Other values required with other devices. these excersices several measurements have been done determine properties used XTAL current gain (transconductance) oscillator gate microcontroller. parameters crystal inverter-gate together determine correct oscillation mode circuit start-up behaviour.
Drive level.
high frequencies, drive levels increased impedance drive level given power, dissipated series resistance XTAL. Hence resonance, current series branch equal current through total parallel capacitance circuit, Fig.2. Vcc=5V, peak peak voltage both sides XTAL Volts, inverted. Hence peak voltage across XTAL 5Volt effective voltage 5V/v2, Vx=3.5V. Then, Vx.Co, (Vx.Co) With Co=Cload= 18pF, 2.35e6 (3.5x235e6x18e-12) This above recommended drive level specified A216 XTAL, Pdmax=500µW. Hence should reduced, selecting lower value Cload. With C1=C2=4.7pF, Cload=3pF, value about 5pF. This will reduce around 1mW, which would safe value prevent intensified ageing.
Conclusion.
From practical test with typical sample overtone XTAL 87C750 microcontroller, found that specified load capacitance high value correct working clock oscillator. With
Oscillators 8-bit microcontrollers
Application Note AN97090
given circuits, good start condition desired overtone mode obtained with reduced load capacitance, e.g. 4.7pF input C2=4.7pF 10pF) output side XTAL,. worst case operation with suppression fundamental mode operation, recommended inductive trap filter frequency, e.g.by connecting L=1.5µH series with Cs=4.7nF, from output ground with C1=4.7pF 22pF.
Oscillators 8-bit microcontrollers
MURATA CERAMIC RESONATORS
Application Note AN97090
alternative traditionally used quartz crystal resonator ceramic resonator. disadvantage ceramic resonator lower frequency accuracy. microcontroller application needs some reason very accurate timing then quartz crystal usually only option. many microcontroller applications timing issues however less critical ceramic resonator will excellent replacement. ceramic resonator several strong advantages: lower price sensitive drive level additional components required higher frequency (overtone). better (mechanical) shock resistance Microcontrollers also available very cost applications requiring suitable resonators. muRata company excellent reputation ceramic technology offering several ranges resonators. many IC's suitable resonator found product programme. Following issues dedicated 8bit microcontroller types.
Resonator types 8400 8051 microcontrollers
Following table lists number PHIILIPS SEMICONDUCTOR microcontroller types that were evaluated muRata with muRata type resonators. These resonator types provide reliable oscillation with microcontroller types involved. external feedback resistor (Rf) that normally required feedback when using unbuffered CMOS gate omitted most cases because integrated most microcontroller oscillator inverters.
MICROCONTROLLER 87C51FA 87C51FA 87C750 P80C52 P80C52 P80C851FBA P80CL51 P80CL51HFT P80CL782 P80LC51HFP P80LC51HFP P80LC51HFP P80LC51HFP P80LC51HFT P80LC51HFT P80LC51HFT P80LC51HFT
CERALOCK CSACS24.00MX040 CSTCS24.00MX0H1 CSTCC6.00MGA0H6 CSA12.0MTZA CST12.0MTWA CSTCS12.0MT CSTCC3.68MG0H6 CSB1000J CSAC6.00MGC CSA10.0MTZ CSA3.58MG CST10.0MTW CST3.58MGW CSA10.0MTZ CSA3.58MG CST10.0MTW CST3.58MGW
CL1[pF]
CL2[pF]
Rf[ohm] Open Open Open Open Open Open Open Open Open Open Open Open Open Open Open Open Open
Rd[ohm] 5.6k
Oscillators 8-bit microcontrollers
P83C575EHP P83C749EFPN P83C750 P83C750 P84C84X P84C84X P87C52 P87C52EBPN P87C52EBPN P87C54IBAA P89CE558EFB PCF80C552-4 PCF80C562 PCF84C00B PCF84C12 PCF84C21 PCF84C21 PCF84C22 PCF84C270 PCF84C444 MICROCONTROLLER PCF84C81AP S87C51FB S87C51FB S87C652 S87C652 S87C654 S87C751 S87C751 S87C751 S87C751 S87C751 CST6.29MGWHA CSA16.00MXZA040 CSA12.0MTZ CST12.0MTW CSA10.0MTZ CST10.0MTW CSA24.00MXZ040 CSA16.00MXZ040 CSA20.00MXZ040 CSA12.0MTZ CST12.0MTWA CST11.0MT020 CSACS11.0MTA CSA6.00MG097 CSA3.58MG310VA CSA3.00MG CST3.00MGW CSA6.00MGA013 CSA3.58MG310VA CSA8.00MTZ CERALOCK CST6.00MGW CSA12.0MTZ CST16.00MXW0C3 CSA10.0MTZ CSACS18.43MX040 CSA12.0MTZ CSA3.58MG CSAC11.9MT CSACS16.00MX040 CST3.58MGW CSTCS16.00MX0C3 CL1[pF] CL2[pF]
Application Note AN97090
Open Open Open Open Open Open Open Open Open Open Open Open Open Open Rf[ohm] Open Open Open Open Open Open Open Open Open Open Open Rd[ohm]
Oscillators 8-bit microcontrollers
Application Note AN97090
Resonator types P87CL884
Recently P87CL884 also evaluated muRata several frequencies resonator giving following results:
6.2.1
types
with CL1=CL2 100pF with CL1=CL2 30pF with CL1=CL2 30pF with CL1=CL2 30pF with CL1=CL2 30pF with CL1=CL2 30pF 4.7kOhm open open open open open open open open open
1.00MHz CSB1000J 2.00MHz CSA2.00MG 2.00MHz CST2.00MG 3.58MHz CSA3.58MG300ABC
with CL1=CL2 30pF(internal)
3.58MHz CST3.58MGW300ABC 4.00MHz CSA4.00MG 4.00MHz CST4.00MGW 8.00MHz CSA8.00MT093 8.00MHz CST8.00MTZ093
with CL1=CL2 30pF(internal) with CL1=CL2 30pF(internal)
6.2.2
12.20 resonators
With these frequencies oscillator signal level small that signal could detected clock (pin18). this reason recommended ceramic resonators these frequencies.
6.2.3
3.58 resonators
Resonator with frequency 3.58 series. These series optimised with DTMF IC's. These resonators have smaller tolerances their frequency match DTMF specification requirements.
Resonator types P80C54/P87C51RA+
PHILIPS SEMICONDUCTOR microcontroller products continually improved technologies. latest versions 80C54 87C51RA+ were also evaluated muRata with resonator types: CSA16.00MXZ040 CST16.00MXW0C3. Results documented report muRata (see ref.
Oscillators 8-bit microcontrollers
REFERENCES
Application Note AN97090
96103. XTAL oscillators 8-Bit microcontrollers. Application note, Pauptit. ETT8710 Specification Quartz ceramic resonators. Lab. report, Jaap Mulder. Techn. note: Start-up conditions Quartz crystal oscillators. Nov. 1989. W.Thommen IEEE circuits. Start-up condition CMOS oscillators. march no.3. Andreas Rusznyak. 456. Using oscillators with Philips microcontrollers. William Houghton. Technical Data Ceramic Resonator, No.TCD-97-5o04, Toyama muRata manufacturing Co,Ltd.
Appendix
following equivalent circuit diagrams apply figures appendix. relevant values listed there Ohm, pF).
App.
Oscillators 8-bit microcontrollers
Application Note AN97090
6.10535 45.5682
Resonator Murata, pins, 12.0T, FS=12.0 4.17542 40.2569
5.28065 47.2664
Resonator Murata, pins, 12.0MTZ, FS=12.0 4.03804 27.0237
Oscillators 8-bit microcontrollers
Application Note AN97090
11.0840 602.177
Resonator Murata, pins, 16.0MX, FS=16.0 165.139 13.0631
9.28503
Resonator 32.768 2.54110 1.27633
Oscillators 8-bit microcontrollers
Application Note AN97090
8.19832 8.46836
Crystal Philips, 12000.000 code 4631.024, Fs=12 20.7893 4.85404
10.8692 13.0490
Crystal Philips, 16000.000 code 200002.017, Fs=16 7.58601 2.13657
Oscillators 8-bit microcontrollers
Application Note AN97090
57.8032 11.8991
Crystal Philips overtone. Code 02370991. Fs=39.130000 Response fundamental frequency, F=13.05 12.4900 2.86327
29.5671 16.8202
Crystal Philips overtone. Code 02370991. Fs=39.130000 Response overtone, F=39.13 0.983545 3.24510
Oscillators 8-bit microcontrollers
Application Note AN97090
72.0326 36.6363
Crystal Philips overtone. Code 02370991. Fs=39.130000 Response overtone frequency, spurious F=39.24 0.448987 2.80858
290.131 113.220
Crystal Philips overtone. Code 02370991. Fs=39.130000 Response overtone, spurious F=39.38 0.144278 2.79147
Oscillators 8-bit microcontrollers
Application Note AN97090
Resonator, Murata, overtone, 36.00 040, Fs=36 MHz. Response overtone around fundamental,
Oscillators 8-bit microcontrollers
Application Note AN97090
Resonator, Murata, overtone, 36.00 040, Fs=36 MHz. Response overtone 75.3167 8.69794
17.4101 259.506
Resonator, Murata, overtone, 36.00 040, Fs=36 MHz. Response overtone spurious frequency 36.4 11.6752 3.69068
177.476 1.63697
Oscillators 8-bit microcontrollers
Application Note AN97090
Resonator, Murata, overtone, 39.00 040, Fs=39 MHz. Response overtone around fundamental,
Oscillators 8-bit microcontrollers
Application Note AN97090
13.8946 209.376
Resonator, overtone, 39.00 040, Fs=39 MHz. Response overtone 38.9 79.9597 9.81582
124.243 1.39105
Resonator, overtone, 36.00 040, Fs=39 MHz. Response overtone 39.3 11.7911 2.78760
Oscillators 8-bit microcontrollers
Application Note AN97090
Crystal IQD. A216, overtone. Fs=35.2512 MHz. Response around overtone fundamental frequencies, 35.2 11.7
Oscillators 8-bit microcontrollers
Application Note AN97090
302.660 22.0710
Crystal IQD. A216, overtone. Fs=35.2512 MHz. Response fundamental frequency, 11.77 8.28450 1.78188
69.0873 29.3083
Crystal IQD. A216, overtone. Fs=35.2512 MHz. Response overtone, 35.256 0.695554 2.19626
Oscillators 8-bit microcontrollers
Application Note AN97090
69.6577 29.2372
Crystal IQD. A216, overtone. Fs=35.2512 MHz. Response overtone, 10pF load added parallel crystal. 35.251 0.697244 12.2397
282.210 112.295
Crystal IQD. A216, overtone. Fs=35.2512 MHz. Response overtone, spurious frequency, 35.32 0.180806 2.02789
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