Crystal Oscillator of the C500 and C166 Microcontroller Families

Microcontrollers
ApNote
AP242005
Crystal Oscillator of the
C500 and C166 Microcontroller Families
The microcontrollers of the C500/C166 Family include the active part of the oscillator. This
document explains the quartz crystal oscillator functionality and gives recommendations
how to get the right composition of external circuits.
Author : Peter Mariutti / MD AE Munich
07.99, Rel. 05
Edition 1999-07
Published by
Infineon Technologies AG
81726 München, Germany
© Infineon Technologies AG 2006.
All Rights Reserved.
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IMPLEMENTATION OF THE INFINEON TECHNOLOGIES COMPONENT ONLY AND SHALL NOT BE
REGARDED AS ANY DESCRIPTION OR WARRANTY OF A CERTAIN FUNCTIONALITY, CONDITION OR
QUALITY OF THE INFINEON TECHNOLOGIES COMPONENT. THE RECIPIENT OF THIS APPLICATION
NOTE MUST VERIFY ANY FUNCTION DESCRIBED HEREIN IN THE REAL APPLICATION. INFINEON
TECHNOLOGIES HEREBY DISCLAIMS ANY AND ALL WARRANTIES AND LIABILITIES OF ANY KIND
(INCLUDING WITHOUT LIMITATION WARRANTIES OF NON-INFRINGEMENT OF INTELLECTUAL
PROPERTY RIGHTS OF ANY THIRD PARTY) WITH RESPECT TO ANY AND ALL INFORMATION GIVEN
IN THIS APPLICATION NOTE.
Information
For further information on technology, delivery terms and conditions and prices please contact your nearest
Infineon Technologies Office (www.infineon.com).
Warnings
Due to technical requirements components may contain dangerous substances. For information on the types
in question please contact your nearest Infineon Technologies Office.
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Crystal Oscillators of the
C500 / C166 Microcontroller Family
Contents
Page
1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2
2.1
2.2
2.3
2.4
2.5
2.6
Oscillator-Inverter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oscillator Inverter Type_A, Type_B and Type_C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oscillator Inverter Type_R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oscillator Inverter Type_RE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oscillator Inverter Type_LP1 and Type_LP2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oscillator Inverter Type_RTC1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oscillator Inverter Type_RTC2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
Fundamental Mode and 3rd Overtone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4
4.1
4.2
Oscillator Start-up Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Definition of the Oscillator Start-up Time tst_up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Definition of the Oscillator Off Time toff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5
5.1
5.2
5.3
Drive Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Measurement Method of Drive Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drive Level Calculation for Fundamental Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drive Level Calculation for 3rd Overtone Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11
11
12
13
6
6.1
6.2
6.3
6.4
6.4.1
6.4.2
6.5
Start-up- and Oscillation Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Principle of the Negative Resistance Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Measurement Method of Start-up- and Oscillation Reliability . . . . . . . . . . . . . . . . . . .
Safety Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Trouble Shooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pull down Resistor RX1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Feedback Resistor Rf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Qualification of the Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14
14
15
17
18
18
18
20
7
7.1
7.2
7.3
7.4
7.5
7.6
Oscillator Circuitry Layout Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Avoidance of Capacitive Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ground Connection of the Crystal Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Avoidance of Parallel Tracks of High Frequency Signals . . . . . . . . . . . . . . . . . . . . . .
Ground Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Correct Module Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Layout Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21
21
21
21
21
21
22
8
Used Short Cuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
9
Recommendations of the Crystal Manufacturer Tele Quarz Group . . . . . . . . . . . . 26
2 of 45
5
5
6
6
6
6
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C500 / C166 Microcontroller Family
10
General Information using the Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
11
11.1
11.2
11.3
11.4
Appendix C500 Family . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C500 Family: Relation between Oscillator-Inverter Type and Device Type . . . . . . . . .
C500 Family: Type_A Oscillator-Inverter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C500 Family: Type_B Oscillator-Inverter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C500 Family: Type_C Oscillator-Inverter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27
27
28
29
30
12
Appendix C166 Family . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.1
C166 Family: Relation between Oscillator-Inverter Type and Device Type . . . . . . . . .
12.2
C166 Family: Type_R and Type_RE Oscillator-Inverters . . . . . . . . . . . . . . . . . . . . . .
12.2.1
C166 Family: Type_R and Type_RE Oscillator-Inverter Fundamental Mode . . . . . .
12.2.2
C166 Family: Type_R and Type_RE Oscillator-Inverter 3rd Overtone Mode . . . . . .
12.3
C166 Family: Type_LP1 Oscillator-Inverter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.4
C166 Family: Type_LP2 Oscillator-Inverter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.5
C166 Family: Type_RTC1 Oscillator-Inverter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.6
C166 Family: Type_RTC2 Oscillator-Inverter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
31
33
34
35
36
37
38
39
13
13.1
13.2
13.3
13.4
13.5
Quartz Crystals for the C500 and C166 Family . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fundamental Mode Quartz Crystal for Standard Temperature Range . . . . . . . . . . . .
Fundamental Mode Quartz Crystal for Advanced Temperature Range . . . . . . . . . . . .
3rd Overtone Mode Quartz Crystal for Standard Temperature Range . . . . . . . . . . . .
3rd Overtone Mode Quartz Crystal for Advanced Temperature Range . . . . . . . . . . . .
Real Time Clock Quartz Crystal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
40
40
41
42
42
43
14
TELE QUARZ GROUP Sales Offices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
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AP242005 ApNote - Revision History
Actual Revision : 07.99
Previous Revision : 04.99
Page of
Page of
actual Rev. prev.Rel.
Subjects (changes since last release)
31
31
“SAx-C161OR FA Type_RE” corrected to “Type_LP2”
33
33
Table 13: “SAx-C161OR FA “ removed
37
37
Table 18: “SAx-C161OR FA “ inserted
31
31
Appendix C166 Family: Oscillator Frequency adapted to Data Sheet
is a trademark of TELE QUARZ GROUP
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1
Introduction
This Application Note provides recommendations concerning the selection of quartz crystals and
circuit composition for each oscillator. The cooperation between the IC oscillator and the quartz
crystal is not always working properly because of a wrong composition of external circuits.
Therefore Infineon Technologies (MD AE) and Tele Quarz Group built up a cooperation to
support our customers with the appropriate knowledge to guarantee a problem-free operation of the
oscillator. The content concerning the measurements to find the right external circuits is a general
information and can be used for all pierce oscillators using an oscillator-inverter.
2
Oscillator-Inverter
The microcontrollers of the C500/C166 Family include the active part of the oscillator (also called
oscillator-inverter). Based on the history and evolution of the microcontrollers there are different
oscillator-inverters implemented at the C500/C166 Family members. Due to the same reason, the
meaning of XTAL1 and XTAL2 pins is different. In this Application Note and at the C166 Family,
XTAL1 is the oscillator-inverter input while XTAL2 is the output. At the C500 Family it is
recommended to have a closer look at the Data Sheet of each device.
Some devices include an auxiliary oscillator. This is a real time clock oscillator-inverter, XTAL3 is
the oscillator-inverter input while XTAL4 is the output.
The on-chip oscillator-inverter can either run with an external crystal and appropriate external
oscillator circuitry (also called oscillator circuitry or passive part of the oscillator), or it can be driven
by an external oscillator. The external oscillator directly connected to XTAL1, leaving XTAL2 open,
feeds the external clock signal to the internal clock circuitry.
The oscillator input XTAL1 and output XTAL2 connect the internal CMOS Pierce oscillator to the
external crystal. The oscillator provides an inverter and a feedback element. The resistance of the
feedback element is in the range of 0.5 to 1 MΩ.
Depending on the type of oscillator-inverter the gain can be different between reset active and reset
inactive. The recommendations in the appendix are separated to the different oscillator-inverter
types of the C500 and C166 Family.
2.1
Oscillator Inverter Type_A, Type_B and Type_C
These types of inverters are implemented in C500 Family derivatives. The gain of these types of
oscillator-inverters is the same during reset active and reset inactive. These oscillators are
optimized for operating frequencies in the range of 2.0 (3.5) to 20 MHz. For details refer to appendix.
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2.2
Oscillator Inverter Type_R
This type of inverter is implemented in most of the current C166 Family derivatives. The gain of the
Type_R oscillator-inverter is high during reset is active and is Reduced by one-third when reset is
inactive. This feature provides an excellent start-up behavior and a reduced supply current for the
oscillator during normal operation mode. The Type_R oscillator-inverter is optimized for an
operating frequency range of 4 to 40 MHz.
2.3
Oscillator Inverter Type_RE
This type of inverter is an enhanced Type_R oscillator-inverter with a high gain but reduced power
consumption. The Type_RE oscillator-inverter is compatible to the external circuits of Type_R.
The gain of this inverter is identical during reset is active and during reset is inactive. The Type_RE
oscillator-inverter will be implemented in new designs requiring an oscillator frequency from 4 to 40
MHz.
2.4
Oscillator Inverter Type_LP1 and Type_LP2
This type of inverter is a Low Power oscillator, version 1 and version 2. Inverter Type_LP2 is the
actual version and will be implemented in new derivatives of the C16x Family. The Type_LP
oscillator-inverter is a high sophisticated module with a high gain but low power consumption. The
gain of the Type_LP oscillator-inverter is the same during reset active and reset inactive. This
oscillator is optimized for an operating frequency range of 4 to 16 MHz. For input frequencies above
25 ... 30 MHz provided by an external oscillator the oscillator’s output should be terminated with a
15 pF capacitance and a 3 kΩ resistor in series to XTAL2.
2.5
Oscillator Inverter Type_RTC1
The auxiliary oscillator-inverter is a Real Time Clock oscillator with a low power consumption and it
is optimized for a frequency range of 32 kHz ± 50%. The feedback resistor Rf of the Type_RTC1 is
integrated on chip. If the auxiliary oscillator-inverter is not used in the system it is recommended to
connect the input (XTAL3) to VDD.
2.6
Oscillator Inverter Type_RTC2
This auxiliary oscillator-inverter is also a Real Time Clock oscillator with an very low power
consumption and it is optimized for a frequency range of 32 kHz ± 50%. The feedback resistor Rf
of the Type_RTC2 is not integrated on chip. Rf has to be connected externaly between pin XTAL3
and XTAL4. If the auxiliary oscillator-inverter is not used in the system it is recommended to connect
the input (XTAL3) to VDD or GND.
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3
Fundamental Mode and 3rd Overtone
Depending on the system demands there are two different kind of oscillator modes available. The
external quartz crystal can be prepared for fundamental mode or 3rd overtone mode.
The standard external oscillator circuitry for fundamental mode (see figure 1) includes the crystal,
two low end capacitors and a series resistor RX2 to limit the current through the crystal. The series
resistor RX2 is not often used in C500 Family devices. A test resistor RQ may be temporarily inserted
to measure the oscillation allowance of the oscillator circuitry. How to check the start-up reliability
will be explained in detail in Chapter 6.
For the 3rd overtone mode an additional inductance/capacitance combination (LX/CX2) is required
to suppress oscillation in the fundamental mode and bias voltage (CX) at the XTAL2 output.
Fundamental mode is suppressed via phase shift and filter characteristics of the LX/CX2 network.
The formula fLXCX2 in chapter 5.3 calculates the frequency at which the inductive behavior of the LX/
CX2 network changes to capacitive. The oscillation condition in 3rd overtone mode needs a
capacitive behavior for f3rd and an inductive one for ffund.
3rd overtone mode is often used in applications where the crystal has to be resistant against strong
mechanical vibrations because 3rd overtone crystals have a higher mechanical stability than
fundamental mode crystals with the same frequency.
In general, there are different possibilities to connect the LX/CX network for 3rd overtone to the
oscillator circuit. The LX/CX network theoretically can be connected to CX1 or CX2. This Application
Note recommends the connection to CX2 (see figure 1) because a little variation of LX caused by
production deviation has more influence concerning the oscillator start-up behavior at the XTAL1
input than at the XTAL2 output. Furthermore, the additional hardware for 3rd overtone mode
receives additional electrical noise from the system. In a CX1/LX/CX combination the noise will be
amplified via the oscillator inverter. In a CX2/LX/CX combination the noise will be damped by the
quartz crystal. Depending on the quality of the Printed Circuit Board design, a CX1/LX/CX
combination can have a bad influence on the start-up behavior of the oscillator.
Note: There is no need of changing existing working designs which use the CX1/LX/CX combination
when the Safety Factor SF is within the desired range.
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3rd Overtone Mode:
(20 ... 40 MHz)
Fundamental Mode:
(4 ... 40 MHz)
to internal
clock circuitry
XTAL1
(XTAL2)
to internal
clock circuitry
XTAL2
(XTAL1)
XTAL1
(XTAL2)
XTAL2
(XTAL1)
RX2
RX2
Q
Q
RQ
RQ
LX
CX1
CX2
CX1
CX2
CX
GND
GND
Figure 1
Oscillator Modes
Note: The operating frequency of the oscillator depends on the type of oscillator-inverter and the
oscillation mode. For detailed information refer to appendix.
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4
Oscillator Start-up Time
Based on small electrical system noise or thermic noise caused by resistors, the oscillation starts
with a very small amplitude. Due to the amplification of the oscillator-inverter, the oscillation
amplitude increases and reaches its maximum after a certain time period tst_up (start-up time). The
oscillator start-up time depends on the oscillator frequency and typical values of the start-up time
are within the range of 0.1 msec ≤ tst_up ≤ 10 msec for an oscillator frequency
2 MHz ≤ fOSC ≤ 40 MHz. The oscillator frequency of the real time clock oscillator are within the
range of 32kHz ± 50% and typical values of the start-up time are within the range of
1 sec ≤ tst_up ≤ 10 sec.
Theoretically the oscillator-inverter performs a phase shift of 180°, and the external circuitry
performs a phase shift of 180° to fulfill the oscillation condition of an oscillator. A total phase shift of
360° is necessary.
In reality, the real phase shift of the oscillator-inverter depends on the oscillator frequency and is
approximately in the range of 100° to 210°. It is necessary to compose the external components in
a way that a total phase shift of 360° is performed. This can be achieved by a variation of C x1 and
Cx2.
Note: During power-on the external hardware reset signal has to be active for a longer time period
than the oscillator start-up time in order to prevent undefined effects.
Note: Because of the different gain of the Type_R oscillator-inverter during reset active and reset
inactive it is recommended to consider the oscillation in both phases of the reset signal.
4.1
Definition of the Oscillator Start-up Time tst_up
The definition of the oscillator start-up time is not a well defined value in literature. Generally it
depends on the power supply rise time dVDD/dt at power on, on the electrical system noise and on
the oscillation amplitude. For this application the oscillator start-up time tst_up is defined from VDD/
2 to 0.9*VOSC_max of the stable oscillation, see figure 2.
Supply Voltage at
XTAL2 Output
VDD
VDD/2
0.9*VOSC_max
Signal at
VOSC_max
XTAL2 Output
t
tst_up
Figure 2
Oscillator Start-up Time
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4.2
Definition of the Oscillator Off Time toff
Measurement of the oscillator start-up time is normally done periodically. After switching off power
supply, the oscillation continues until the whole reactive power oscillating between inductance and
capacitance is consumed. Therefore the time between switching off and on (toff) the power supply
must not be too short in order to get reproduceable results. toff depends on the composition of the
oscillator components.
It is recommended to use an oscillation off time toff ≥ 0.5 sec for an oscillator frequency within the
range of 2 MHz ≤ fOSC ≤ 40 MHz, see figure 3.
The off time of a real time clock oscillator sholuld be at least toff ≥ 60 sec.
VDD
t
toff
toff
Figure 3
Oscillator Off Time
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5
Drive Level
5.1
Measurement Method of Drive Current
The amplitude of mechanical vibration of the quartz crystal increases proportionally to the amplitude
of the applied current. The power dissipated in the load resonance resistance RL (in other technical
descriptions also called ’effective resistance’ or ’transformed series resistance’) is given by the drive
level PW. The peak to peak drive current Ipp is measured in the original application with a current
probe directly at the crystal lead, see figure 4. The drive level is calculated with the formulas shown
in chapters 5.2 and 5.3. The drive level is mainly controlled via R X2 and CX1, but CX2 also has an
influence.
XTAL2
(XTAL1)
XTAL1
(XTAL2)
Ipp
Current Probe
RX2
Q
RQ
CX2
CX1
(3rd Overtone)
LX
CX
GND
Figure 4
Measurement Method of Drive Current with a Current Probe
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5.2
Drive Level Calculation for Fundamental Mode
The maximum and minimum allowed drive level depends on the used crystal and should be within
the typical range of 50 µW ≤ PW ≤ 800 µW. For detailed information, the quartz crystal data sheet
has to be regarded.
The load resonance resistance RLtyp is calculated with the typical values of the quartz crystal and
of the system. The formula is shown below. The typical values of R 1 (R1typ) and C0 (C0typ) are
supplied by the crystal manufacturer. The stray capacitance CS consists of the capacitance of the
board layout, the input capacitance of the on-chip oscillator-inverter and other parasitic effects in the
oscillator circuit. A typical value of the input pin capacitance of the inverter is 2 pF. The maximum
value is 10 pF. A typical value of the stray capacitance in a normal system is CS = 5 pF.
Drive level:
2
P W = IQ ⋅ R Ltyp
Drive Current:
Ipp
I Q = --------------- (for sine wave)
2⋅ 2
Load Resonance Resistance:
C 0typ 2
R Ltyp = R 1typ ⋅ 1 + ----------------CL
Load Capacitance:
C X1 ⋅ C X2
- + CS
C L = ----------------------------------( C X1 + C X2 )
Note: The drive level calculation in systems with a Type_R oscillator-inverter should be done with
the drive current (IQ) measured during reset is inactive. Using an optimized external circuitry
the difference of IQ during reset active and reset inactive is very small.
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5.3
Drive Level Calculation for 3rd Overtone Mode
The calculation of the drive level in 3rd overtone mode is equal to fundamental mode besides the
calculation of the load capacitance. The formulas below show the relations between load
capacitance, circuit components and frequencies in 3rd overtone.
Load Capacitance:
C X1 ⋅ C X2rest
C L = ------------------------------------------ + CS
C X1 + C X2rest
CX2 rest Capacitance:
1
C X2rest = C X2 – ---------------------------------------2
( 2πf 3rd ) ⋅ L X
Resonance Frequency of CX2 and LX (Thomson Formula):
1
f LXCX2 = ----------------------------------------2π ⋅ L X ⋅ C X2
Relation between ffund and f3rd:
f fund + f 3rd
f LXCX2 ≈  ----------------------------- = 2 ⋅ f fund

2
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6
Start-up- and Oscillation Reliability
Most problems concerning the oscillator in a microcontroller system occur during the oscillation
start-up time. During start-up time the drive level of the oscillation is very small and is increased up
to the maximum. During that time the resistance of the crystal can reach high values because
crystals show resistance dips depending on the drive level and the temperature. This effect is called
drive level dependence (DLD). The DLD of a quartz crystal depends on the quality and can alter
during production and during the life time of the crystal. If the resistance dips of the crystal increase
in a range where the amplification of the oscillator is lower than one, than the oscillation cannot start.
Therefore it is strongly recommended to check the start-up and oscillation reliability .
This test is done with the negative resistance method.
For further details please refer to the following IEC standards:
IEC 122-2-1: Quartz crystal units for microprocessor clock supply
IEC 444-6: Measurement of drive level dependence (DLD)
6.1
Principle of the Negative Resistance Method
The oscillator can be divided into the on-chip oscillator-inverter and the external circuitry. The
oscillator circuitry can be simplified as shown in figure 5. The load capacitance C L contains CX1, CX2
and the stray capacitance CS. The amplification ability of the oscillator-inverter is replaced with a
negative resistance -RINV and the quartz crystal is replaced by the load resonance resistance R L
(effective resistance) and the effective reactance LQ.
Oscillator Circuit
Equivalent Circuit of Oscillator Circuit
Rfint
Microcontroller
-RINV
XTAL1
CL
CS
CX1
XTAL2
CX2
Q
CL
LQ
RL
RQ
RQ
Figure 5 :
Equivalent Circuit for Negative Resistance Methode
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The condition required for oscillation is:
– R INV ≥ R L
The negative resistance has to be large enough to cover all possible variation of the oscillator
circuitry. This condition is necessary to guarantee a problem-free operation of the oscillator. The
negative resistance can be analyzed by connecting a series test resistor RQ to the quartz crystal
(see figure 5) used to find the maximum value RQmax that remains the circuit still oscillating. RL is
the resistance of the quartz crystal at oscillating frequency and creates the power dissipation.
Negative Resistance:
6.2
– R INV = R L + R Qmax
Measurement Method of Start-up- and Oscillation Reliability
As already mentioned before, the resistance of a crystal depends on the drive level. A simple
method to check the start-up and oscillation reliability of the oscillator is to insert a test resistor RQ
in series into the quartz crystal, see figure 4.
The basic timing of VDD during testing is equal to the described timing for testing the oscillation startup time (see chapter ’oscillation start-up time’). The value of RQ is increased until the oscillation
does not start any more . From the state of no oscillation RQ is then decreased until oscillation starts
again. Using a Type_R oscillator-inverter this procedure has to be considered during reset active
and reset inactive. This final value of RQmax is used for further calculations of the Safety Factor SF.
Note: The series resistor RQ should be an SMD device or a potentiometer which is suitable for RF
(Radio Frequency). Depending on the RF behavior of the potentiometer, the results between
using an SMD resistor or a potentiometer can be different. The result of the potentiometer is
sometimes worse than the one of the SMD resistor. It is therefore recommended to use the
potentiometer in order to find the final value RQmax and to perform a verification of RQmax with
a SMD resistor.
Note: The start-up and oscillation reliability can be also influenced by using a socket for the
microcontroller during measurement. The influence is caused by the additional inductance
and capacitance of the socket. Depending on the demands to the final system which is used
for mass production the consideration of start-up and oscillation reliability has to be done with
or without a socket. The recommendations in the appendix are verified without socket.
Note: Depending on the system demands the verification of the start-up and oscillation reliability
should be also done for variation of supply voltage and temperature.
Note: Also refer to IEC 60679-1 clause 4.5.9
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Table 1
Element Range for Test
Element
Range
CX1 = CX2
0 - 100 pF
RX2
0 - 10 kΩ
3rd Overtone: LX
1 - 15µH
3rd Overtone: CX
1 - 10nF
The described measurement procedure for RQmax has to be performed for different values of RX2,
CX1 and CX2. During the test, the values of the different elements have to be changed one after
another, and the results are noted in a table. A proposal for a protocol table is shown in table 2. For
the first test it is recommended to use CX1 = CX2. A suggestion for the range is given in table 1. The
range of the elements depends on the used quartz crystal and on the characteristics of the printed
circuit board. After the test the measured values should be displayed in a diagram, see figure 7.
The measurement method of start-up and oscillation reliability for 3rd overtone mode needs more
efforts than for fundamental mode. The relation between the values of LX and CX2 is given via the
formulas in chapter 5.3. When CX lies within the recommended range it has theoretically no effect
on the start-up behavior of the oscillator, but in a system the parasitic inductive part of C X can have
a little influence. CX is only needed in order to suppress bias voltage at XTAL2 output.
Recommended values are shown in table 1.
Table 2
Proposal for a Protocol Table
RX2= ... Ohm
CX1 = CX2
IQ or Pw
RQmax
Comment
0 pF
2.7 pF
...
10 pF
...
...
...
as
Me
u
e
rem
nt
ul
s
e
R
ts
47 pF
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6.3
Safety Factor
The Safety Factor SF is the relation between maximum test resistance RQmax, which can be added
in series to the quartz crystal but it is still oscillating, and the maximum load resonance resistance
RLmax. It gives a feeling of how much the resistance of the passive part of the oscillator circuitry can
be increased (caused by the drive level dependence of the crystal) until the oscillation does not start
any more. Depending on production quality and long time behavior of all parts of the oscillator
circuitry, the Safety Factor needs a certain minimum value to grant a problem-free operation of the
oscillator for mass production and during life time. The qualification of the Safety Factor shown in
table 3 is based on the experience of the Tele Quarz Group.
Safety Factor:
R Qmax
SF = --------------------R Lmax
Load Resonance Resistance:
C 0typ 2
R Lmax = R 1max ⋅ 1 + ----------------CL
Table 3
Qualification of the Safety Factor
Safety Factor
Qualification
SF < 1.5
unsuitable
1.5 ≤ SF < 2
risky
2 ≤ SF < 3
suitable
3 ≤ SF < 5
safe
SF ≥ 5
very safe
Note: For oscillation frequencies higher than 24MHz it is strongly recommended to check whether
the Safety Factor which can be achieved is sufficient for the system. In case the Safety
Factor is not sufficient in fundamental mode, it is possible to use 3rd overtone mode (see
appendix).
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6.4
Trouble Shooting
For standard applications, the already described method to determine the Safety Factor by
changing the load capacitors is sufficient and successful finding a appropriate Safety Factor. If the
application system shows still problems, despite all information given in this application note was
regarded then the following hints can solve the problem.
6.4.1 Pull down Resistor RX1
An additional resistor RX1, within the value 5 MΩ to 12 MΩ, in parallel to CX1 can also increase the
Safety Factor, since the internal feedback resistor of the oscillator-inverter and the additional
external resistor form a voltage divider at the input of the inverter, see figure 6. This combination
decreases damping in the active part of the inverter. Therefore the start-up behavior of the
oscillation is improved, and the Safety Factor is increased. The additional resistor R X1 should only
be used when the oscillation circuit is already optimized but the Safety Factor is not sufficient for the
application.
6.4.2 Feedback Resistor Rf
An additional external feedback resistor with a value Rf ~ 100kΩ stabilizes the operating point (DC
point) of the oscillator inverter input, see figure 6. This combination improves the start-up behavior
in an application system with much noise caused by adjacent components or in systems with
disturbance on the supply voltage. This problem can be seen in a start-up time which is to long or
in a start-up time which is not stable. The additional external resistor R f should only be used when
the oscillation circuit is already optimized but the Safety Factor or start-up behavior is not sufficient
for the application.
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Feedback Resistor Rf
Pull down Resistor RX1
to internal
clock circuitry
XTAL2
(XTAL1)
XTAL1
(XTAL2)
to internal
clock circuitry
XTAL2
(XTAL1)
XTAL1
(XTAL2)
Rf
RX2
RX2
Q
RX1
CX1
Q
CX2
CX1
GND
CX2
GND
Figure 6
Pull down Resistor RX1 and Feedback Resistor Rf for Trouble shooting
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6.5
Qualification of the Results
The basis for the evaluation of the measured results are the protocol tables. The results are
displayed in evaluation diagrams shown in figure 7. For each protocol table with a fixed R X2 one
evaluation diagram should be used. The evaluation diagram includes the characteristic curve for the
Safety Factor SF and the drive level PW. It is also possible to display the resistance of the test
resistor RQ and the crystal current IQ.
In the evaluation diagram the specified minimum and maximum values of PW (IQ) of the used crystal
can be marked. From it results a fixed range for the allowed capacitance of CX1 and CX2. Depending
on the circuit composition, the characteristic curve of SF (RQmax) includes very often a maximum for
capacitance values in the CX1/ CX2 range of 0 pF to 3 pF. The recommended range for SF (RQmax)
should be in the falling area of the characteristic curve as marked in the diagram. Depending on the
selected area for SF (RQmax) a specific range for CX1 and CX2 is given.
Now two areas for CX1 and CX2 are given, one by PW (IQ) and the other by SF (RQmax). The
capacitive values which are available in both areas are allowed for the oscillator circuit (see marked
area in the diagram). This analysis has to be done for every RX2 value. The final selection of the
components should be done under consideration of the necessary safety level, frequency, quality of
the start-up behavior of the oscillator, start-up time of the oscillation and the specified load
capacitance CL of the crystal.
Note: It is not recommended to include the maximum of SF (RQmax) because in many cases the
gradient of the characteristic curve between 0 pF and 3 pF is very high. If CX1 and CX2 were
chosen in that area, small parameter variations of the used components during production
could reduce the safety level very fast. The consequence could be that the oscillator does not
work in this case.
SF (Safety Factor)
RX2 = ... Ohm
PW (Drive Level)
recomm.
range
max.
allowed
range
min.
0
CX1 / CX2
[pF]
Range for
CX1 / CX2
Figure 7
Evaluation Diagram for CX1 and CX2
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7
Oscillator Circuitry Layout Recommendations
The layout of the oscillator circuit is important for the RF and EMC behavior of the design. The use
of this recommendation can help to reduce problems caused by the layout. This design
recommendation is optimized on EMC aspects.
For an optimal layout the following items have to be noted:
7.1
Avoid Capacitive Coupling
The crosstalk between oscillator signals and others has to be minimized. Sensitive inputs have to
be separated from outputs with a high amplitude.
Note: The crosstalk between different layers also has to be analyzed.
7.2
Ground Connection of the Crystal Package
The connection of the crystal package to the ground plane directly underneath the crystal and to the
ground layer via an interlayer connection has the following advantages:
•
•
The crystal metal package reduces the electromagnetic emission.
The mechanical stability of the crystal can be increased.
The ground layer and the additional ground plane underneath the crystal shield the oscillator. This
shielding decouples all signals on the other PCB side.
7.3
Avoid Parallel Tracks of High Frequency Signals
In order to reduce the crosstalk caused by capacitive or inductive coupling, tracks of high frequency
signals should not be routed in parallel (also not on different layers!).
7.4
Ground Supply
The ground supply must be realized on the base of a low impedance. The impedance can be made
smaller by using thick and wide ground tracks. Ground loops have to be avoided, because they are
working like antennas.
Note: The connection to the ground should be done with a top-pin-clip because the heat of
soldering can damage the quartz crystal.
7.5
Noise Reduction on Ground of the Load Capacitors
Noise on the ground track between the load capacitors and the on-chip oscillator ground can have
an influence on the duty cycle. This is important for systems running in direct drive mode (oscillator
frequency is equal to CPU frequency). Therefore the ground connection of the decoupling
capacitance CB (between VDD and VSS of the on-chip oscillator-Inverter) should be between VSS and
system ground connection, to suppress noise from system ground, see figure 9.
7.6
Correct Module Placement
Other RF modules should not be placed near the oscillator circuitry in order to prevent them from
influencing the crystal functionality.
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7.7
Layout Examples
Microcontroller
Decoupling capacitance CB
on the back side of the PCB
CB
XTAL1
Connection to
ground layer
VSS
RX2
VDD
CX1
XTAL2
CX2
Quartz
Crystal
Connection to
ground layer
Quartz Crystal package
has to be grounded
Connection to
ground layer
GND
Figure 8
Layout Example for a leaded Quartz Crystal
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Connection to
system ground
Microcontroller
Decoupling capacitance CB
on the back side of the PCB
Connection to system VDD
Via to ground island and
system ground
CB
Via to system VDD
VSS
VDD
XTAL2
XTAL1
Single ground island
GND
RX2
SMD
Quartz Crystal
Vias to ground island
CX1
CX2
Figure 9
Layout Example for a SMD Quartz Crystal
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8
Used Short Cuts
C0
: Shunt capacitance of the quartz crystal (static capacitance).
C0typ
: Typical value of the shunt capacitance of the quartz crystal.
C1
: Motional capacitance of the quartz crystal (dynamic capacitance).
Mechanical equivalent is the elasticity of the quartz crystal hardware blank.
C1typ
: Typical value of the motional capacitance of the quartz crystal.
CL
: Load capacitance of the system resp. quartz crystal.
CS
: Stray capacitance of the system.
CX1, CX2
: Load capacitors
CX
: Capacitance to suppress bias voltage at XTAL2 output.
CX2rest
: Capacitance of CX2 in combination with LX in 3rd overtone mode.
CB
: Decoupling capacitance for VDD and VSS on the Printed Circuit Board (PCB).
Depending on the EMC behavior the value should be in the range: 22nF to 100nF.
fLXCX2
: Parallel resonance frequency of LX and CX2
f3rd
: Frequency of the 3rd overtone
ffund
: Frequency of the fundamental mode
Ipp
: Peak to peak value of the quartz crystal current.
IQ
: Drive current
L1
: Motional inductance of the quartz crystal (dynamic inductance).
Mechanical equivalent is the oscillating mass of the quartz crystal hardware blank.
LX
: Inductance for 3rd overtone mode.
LQ
: Effective
PW
: Drive level
Q
: Quartz Crystal
reactance
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R1, Rr
: Series resistance of the quartz crystal (resonance resistance) in other technical
descriptions also called: ’equivalent series resistance, ESR’ or ’transformed
series resistance’). Mechanical equivalent is the moleculare friction, the damping
by mechanical mounting system and accustical damping by the gasfilled housing.
R1typ
: Typical value of the series resistance at room temperature.
R1max
: Maximum value of the series resistance at room temperature.
R1max (TK)
: Maximum value of the series resistance at the specified temperatur range.
This value ist the base for calculation of the SF in this application note.
RLtyp, RLmax: Typical and maximum load resonance resistor (in other technical descriptions also
called: ’effective resistance’). RL is the resistance of the quartz crystal at oscillating
frequency and creates the power dissipation
RQ
: Test resistor for calculation of safety level “critical starting resistance”.
RQmax
: Maximum value of the test resistor which does not stop the oscillation.
RX1
: Pull down resistor to increase gain (trouble shooting).
RX2
: Resistor which controls the drive level (damping resistor).
Rf
: Additional external feedback resistor to stabilize DC point (trouble shooting).
SF
: Safety Factor
tst_up
: Start-up time of the oscillator
toff
: Oscillator off time for measurement of start-up behavior
L1
C1
R1
Q
C0
Figure 10
Equivalent Circuit of a Quartz Crystal
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9
Recommendations of the Crystal Manufacturer Tele Quarz Group
The preceding chapters have shown a possibility of how to find the appropriate values for the circuit
components of a crystal oscillator circuitry which ensure a problem-free operation. Similar tests
were done in a cooperation between Infineon Technologies (MD AE) and Tele Quarz Group. This
work is already performed for different Infineon Technologies microcontrollers. The specialists of
Tele Quarz Group have done the analyses with the aid of the microcontroller development group of
Infineon Technologies MD AE. The results of this cooperation are presented in the appendix of this
Application Note. The cooperation will be continued and the results will be added to this Application
Note step by step.
Note: The appendix shows recommendations for the appropriate circuit composition of the
oscillator which run in most of all applications but they do not release the system designer
from a verification in the original system M. It is mandatory to perform own
investigations concerning the Safety Factor to get a problem-free operation of the oscillator.
This is necessary because every design has a specific influence on the oscillator (noise,
layout etc.).
10
General Information using the Appendix
The Appendix includes recommendations for the right composition of external circuits for the C500
and C166 Family. Each recommendation for the external circuits is only one of more different
possibilities. The decision which composition is the right one, is not ’digital’ (go or no go) but has to
be done in an ’analog’ way which offers more different results which fits to the system. The system
designer has to decide which criterion of the application system concerning the oscillator has to be
considered: Safety Factor, start-up behavior, drive level, quartz crystal specification, frequency,
EMC, layout demands etc. These facts are the base for the trade-off which external circuits fit best
to the individual application system.
The most important topic of the oscillator is the Safety Factor which gives the system designer a
feeling about the start-up quality of the oscillator. The recommendations in the appendix show one
possibility for the external circuits which is optimized to the start-up behavior respectively the Safety
Factor and the used type of quartz crystal.
For microcontroller and quartz crystals which are not included in the tables please determine the
Safety Factor in the target system with the negative resistance metod as described in this
Application Note.
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11
Appendix C500 Family
All derivatives, steps and oscillator-inverter types of the C500 Family shown in the table below are
included in the recommendations of the following pages. For each type of oscillator-inverter there is
given a proposal for the right composition of external circuits refered to different frequencies.
11.1 C500 Family: Relation between Oscillator-Inverter Type and Device Type
Table 4
C500 Family Derivatives and Oscillator-Inverter Type
Device
Step
Inverter
SAx-C505A-4E
AA
Type_A
SAx-C505C-2E
AA
Type_A
SAx-C505CA-4E
AA
Type_A
SAx-C513A-L / -R / -2R
BB
Type_A
SAx-C515C-L / -8R
AA
Type_B
SAx-80C517
SAx-80C537
DB
Type_B
SAx-C509L
DA, DB
Type_C
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11.2 C500 Family: Type_A Oscillator-Inverter
The table below contains the recommendations for the external circuitry using a Type_A oscillatorinverter in fundamental mode. The quartz crystal data are included which are necessary for the
calculation of the drive level (PW) and Safety Factor (SF). The quartz crystal data are related to the
quartz crystals of appendix Quartz Crystals. The measured values of R Qmax and the calculated
values of PW and SF are based on these quartz crystals and the formulas presented in this ApNote.
Table 5
C166 Family Derivatives including a Type_A Oscillator-Inverter
Device
Step
Oscillator Frequency
XTAL1
XTAL2
SAx-C505A-4E
AA
2 - 20 MHz
Input
Output
SAx-C505C-2E
AA
2 - 20 MHz
Input
Output
SAx-C505CA-4E
AA
2 - 20 MHz
Input
Output
SAx-C513A-L / -R / -2R
BB
3,5 - 12 MHz
Input
Output
Table 6
Recommendations for external circuitry used with a Type_A Oscillator-Inverter in
Fundamental Mode
Fundamental Mode:
Type_A Oscillator-Inverter
Safety Factor SF
20
60
80
230
560
3,57
18
56
8,2
18
14
4
20
60
80
356
560
4,23
16
100
8,2
22
13
4
20
60
80
310
560
4,09
12
100
8,2
33
13
4
30
70
90
190
820
5,33
10
150
10
33
14
3
30
80
100
160
820
5,56
8
150
10
33
15
3
35
80
100
150
1200
8,33
6
390
10
33
14
3
35
80
140
120
2700
13,08
5
390
12
33
18
3
35
80
140
50
3900
20,47
4
390
12
33
16
4
20
80
150
40
5600
23,89
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R1max (TK) [Ω]
4
R1max [Ω]
10
R1typ [Ω]
15
C0typ [pF]
8,2
CL [pF]
56
CX1 [pF] (Input)
20
RX2 [Ω]
RQmax [Ω]
Quartz Crystal Data
PW [µW]
(@ 25°C, R1typ)
CX2 [pF] (Output)
Frequency [MHz]
External Circuits
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11.3 C500 Family: Type_B Oscillator-Inverter
The table below contains the recommendations for the external circuitry using a Type_B oscillatorinverter in fundamental mode. The quartz crystal data are included which are necessary for the
calculation of the drive level (PW) and Safety Factor (SF). The quartz crystal data are related to the
quartz crystals of appendix Quartz Crystals. The measured values of R Qmax and the calculated
values of PW and SF are based on these quartz crystals and the formulas presented in this ApNote.
Table 7
C166 Family Derivatives including a Type_B Oscillator-Inverter
Device
Step
Oscillator Frequency
XTAL1
XTAL2
SAx-C515C-L / -8R
AA
2 - 10 MHz
Output (CX2)
Input (CX1)
SAx-80C517
SAx-80C537
DB
3,5 - 16 MHz
Input (CX1)
Output (CX2)
Table 8
Recommendations for external circuitry used with a Type_B Oscillator-Inverter in
Fundamental Mode
Fundamental Mode:
Type_B Oscillator-Inverter
PW [µW]
(@ 25°C, R1typ)
RQmax [Ω]
Safety Factor SF
20
60
80
333
560
4,09
12
56
10
18
13
4
30
70
90
249
560
3,64
10
100
10
27
14
3
30
80
100
190
680
4,61
8
100
10
27
15
3
35
80
100
160
820
5,69
6
150
10
33
14
3
35
80
140
133
1500
7,27
5
150
12
33
18
3
35
80
140
65
1800
9,45
4
150
12
33
16
4
20
80
150
45
3300
14,08
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R1max (TK) [Ω]
4
R1max [Ω]
13
R1typ [Ω]
12
C0typ [pF]
6,8
CL [pF]
0
CX2 [pF] (Output)
16
CX1 [pF] (Input)
RX2 [Ω]
Quartz Crystal Data
Frequency [MHz]
External Circuits
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11.4 C500 Family: Type_C Oscillator-Inverter
The table below contains the recommendations for the external circuitry using a Type_C oscillatorinverter in fundamental mode. The quartz crystal data are included which are necessary for the
calculation of the drive level (PW) and Safety Factor (SF). The quartz crystal data are related to the
quartz crystals of appendix Quartz Crystals. The measured values of R Qmax and the calculated
values of PW and SF are based on these quartz crystals and the formulas presented in this ApNote.
Table 9
C166 Family Derivatives including a Type_C Oscillator-Inverter
Device
SAx-C509L
Step
Oscillator Frequency
XTAL1
XTAL2
DA, DB
3,5 - 16 MHz
Output (CX2)
Input (CX1)
Table 10
Recommendations for external circuitry used with a Type_C Oscillator-Inverter in
Fundamental Mode
Fundamental Mode:
Type_C Oscillator-Inverter
Safety Factor SF
20
60
80
313
820
5,99
12
100
8,2
18
13
4
30
70
90
231
1000
6,50
10
100
10
27
14
3
30
80
100
210
1000
6,78
8
100
10
27
15
3
35
80
100
165
1500
10,42
6
150
10
33
14
3
35
80
140
150
1800
8,72
5
150
12
33
18
3
35
80
140
60
3300
17,32
4
150
12
33
16
4
20
80
150
50
3900
16,64
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R1max (TK) [Ω]
4
R1max [Ω]
13
R1typ [Ω]
12
C0typ [pF]
6,8
CL [pF]
56
CX1 [pF] (Input)
16
RX2 [Ω]
RQmax [Ω]
Quartz Crystal Data
PW [µW]
(@ 25°C, R1typ)
CX2 [pF] (Output)
Frequency [MHz]
External Circuits
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Crystal Oscillators of the
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12
Appendix C166 Family
All derivatives, steps and oscillator-inverter types of the C166 Family shown in the table below are
included in the recommendations of the following pages. For each type of oscillator inverter there is
given a proposal for the right composition of external circuits refered to different frequencies.
12.1 C166 Family: Relation between Oscillator-Inverter Type and Device Type
Table 11
C166 Family Derivatives and Oscillator-Inverter Type
Device
SAx-C161RI
SAx-C161CI
SAx-C161JI
Step
Inverter
AA
Type_LP1
BA, BB
Type_LP2
AA, AB
Main:
Aux:
Type_LP2
Type_RTC1
BA, BB
Main:
Aux:
Type_LP2
Type_RTC2
AC, BA, CA
Main:
Aux:
Type_LP2
Type_RTC2
SAx-C161V / K / O
AA
Type_R
SAx-C161V / K / O
FA
Type_RE
SAx-C161OR
FA
Type_LP2
SAx-C163-LF
AB, AC
Type_R
AA, AB, BA, BB
Type_R
BA, BC, CA
Type_LP2
SAx-C165-LF / -LM
CA
Type_R
SAx-C165-LF
FA
Type_RE
SAB-80C166(W)-M-Tx
CB, DA, DB, DC
Type_R
SAB-83C166(W)-M-Tx
CB, DA, DB, DC
Type_R
SAx-C163-16FF
SAx C164CI
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Table 11
C166 Family Derivatives and Oscillator-Inverter Type (continued)
SAx-C167-LM
SAx-C167S-4RM
SAx-C167SR-LM
SAx-C167CR-LM
SAx-C167CR-4RM
SAx-C167CR-16RM
SAx-C167CS-32FM
BA, BB, BC
Type_R
AA, AE, BA, BB, DA, DB
Type_R
FA
Type_RE
AB, BA, CB, DA, DB
Type_R
FA
Type_RE
AB, BA, BB, CA, CB, BE, DA, DB
Type_R
FA
Type_RE
AA, AB, AC, DA, DB
Type_R
FA
Type_RE
AA
Type_R
FA
Type_RE
AB, AC, AD, AE, BA, BB
Type_LP2
CA, CB, DA
Type_RE
32 of 45
AP242005 07.99
Crystal Oscillators of the
C500 / C166 Microcontroller Family
12.2 C166 Family: Type_R and Type_RE Oscillator-Inverters
The tables below show the derivatives including Type_R and Type_RE oscillator-inverters. The
tables on the next two pages include the recommendations for fundamental mode and 3rd overtone
mode for both oscillator types.
Table 12
C166 Family Derivatives including a Type_R Oscillator-Inverter
Device
Step
Oscillator Frequency
AA
4 - 24 (40) MHz
AB, AC
4 - 24 (40) MHz
AA, AB, BA, BB
4 - 24 (40) MHz
CA
4 - 24 (40) MHz
SAB-80C166(W)-M-Tx
CB, DA, DB, DC
4 - 24 (40) MHz
SAB-83C166(W)-M-Tx
CB, DA, DB, DC
4 - 24 (40) MHz
BA, BB, BC
4 - 24 (40) MHz
SAx-C167S-4RM
AA, AE, BA, BB, DA, DB
4 - 24 (40) MHz
SAx-C167SR-LM
AB, BA, CB, DA, DB
4 - 24 (40) MHz
SAx-C167CR-LM
AB, BA, BB, CA, CB, BE, DA, DB
4 - 24 (40) MHz
SAx-C167CR-4RM
AA, AB, AC, DA, DB
4 - 24 (40) MHz
SAx-C167CR-16RM
AA
4 - 24 (40) MHz
SAx-C161V / K / O
SAx-C163-LF
SAx-C163-16FF
SAx-C165-LF / -LM
SAx-C167-LM
Table 13
C166 Family Derivatives including a Type_RE Oscillator-Inverter
Device
Step
Oscillator Frequency
SAx-C161V / K / O
FA
4 - 24 (40) MHz
SAx-C165-LF
FA
4 - 24 (40) MHz
SAx-C167S-4RM
FA
4 - 24 (40) MHz
SAx-C167SR-LM
FA
4 - 24 (40) MHz
SAx-C167CR-LM
FA
4 - 24 (40) MHz
SAx-C167CR-4RM
FA
4 - 24 (40) MHz
SAx-C167CR-16RM
FA
4 - 24 (40) MHz
SAx-C167CS-32FM
CA, CB, DA
4 - 24 (40) MHz
33 of 45
AP242005 07.99
Crystal Oscillators of the
C500 / C166 Microcontroller Family
12.2.1 C166 Family: Type_R and Type_RE Oscillator-Inverter Fundamental Mode
The table below contains the recommendations for the external circuitry using Type_R or Type_RE
oscillator-inverters in fundamental mode. The quartz crystal data are included which are necessary
for the calculation of the drive level (PW) and Safety Factor (SF). The quartz crystal data are related
to the quartz crystals of appendix Quartz Crystals. The measured values of RQmax and the
calculated values of PW and SF are based on these quartz crystals and the formulas presented in
this ApNote.
Table 14
Recommendations for external circuitry used with Type_R or Type_RE Oscillator-Inverters
in Fundamental Mode
Type_R and Type_RE Oscillator-Inverters
Safety Factor SF
RQmax [Ω]
PW [µW]
(@ 25°C, R1typ)
R1max (TK) [Ω]
R1max [Ω]
R1typ [Ω]
Quartz Crystal Data
CL [pF]
CX2 [pF] (Output)
CX1 [pF] (Input)
RX2 [Ω]
Frequency [MHz]
External Circuits
C0typ [pF]
Fundamental Mode:
40
0
12
15
13
5
10
50
60
420
300
2,60
32
0
12
15
11
5
15
50
60
520
390
3,07
24
180
15
22
12
5
15
50
60
510
390
3,24
20
390
8,2
39
10
4
20
60
80
375
560
3,57
18
390
12
39
14
4
20
60
80
335
540
4,08
16
390
12
47
13
4
20
60
80
353
580
4,24
12
390
12
47
13
4
30
70
90
312
1000
6,50
10
390
15
47
14
3
30
80
100
216
1200
8,14
8
390
15
47
15
3
35
80
100
372
1800
12,50
6
390
15
47
14
3
35
80
140
100
2200
10,66
5
390
22
47
18
3
35
80
140
110
2700
14,17
4
390
22
47
16
4
20
80
150
46
3300
14,08
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AP242005 07.99
Crystal Oscillators of the
C500 / C166 Microcontroller Family
12.2.2 C166 Family: Type_R and Type_RE Oscillator-Inverter 3rd Overtone Mode
The table below contains the recommendations for the external circuitry using Type_R or Type_RE
oscillator-inverters in 3rd overtone mode. The quartz crystal data are included which are necessary
for the calculation of the drive level (PW) and Safety Factor (SF). The quartz crystal data are related
to the quartz crystals of appendix Quartz Crystals. The measured value of R Qmax and the calculated
values of PW and SF are based on these quartz crystals and the formulas presented in this ApNote.
Table 15
Recommendations for external circuitry used with Type_R or Type_RE Oscillator-Inverters
in 3rd Overtone Mode
3rd Overtone Mode:
Type_R or Type_RE Oscillator-Inverters
5,6
10
10
4,7
7
5
35 of 45
12
35
40
700
560
Safety Factor SF
RQmax [Ω]
PW [µW]
(@ 25°C , R1typ)
R1max (TK) [Ω]
R1max [Ω]
R1typ [Ω]
C0typ [pF]
CL [pF]
Quartz Crystal Data
LX [µH]
CX [nF]
100
CX2 [pF] (Output)
RX2 [Ω]
40
CX1 [pF] (Input)
Frequency [MHz]
External Circuits
4,76
AP242005 07.99
Crystal Oscillators of the
C500 / C166 Microcontroller Family
12.3 C166 Family: Type_LP1 Oscillator-Inverter
The table below contains the recommendations for the external circuitry using a Type_LP1
oscillator-inverter in fundamental mode. The quartz crystal data are included which are necessary
for the calculation of the drive level (PW) and Safety Factor (SF). The quartz crystal data are related
to the quartz crystals of appendix Quartz Crystals. The measured values of RQmax and the
calculated values of PW and SF are based on these quartz crystals and the formulas presented in
this ApNote.
Table 16
C166 Family Derivatives including a Type_LP1 Oscillator-Inverter
Device
Step
Oscillator Frequency
AA
4 - 16 MHz
SAx-C161RI
Table 17
Recommendations for external circuitry used with a Type_LP1 Oscillator-Inverter in
Fundamental Mode
Fundamental Mode:
Type_LP1 Oscillator-Inverter
PW [µW]
(@ 25°C, R1typ)
RQmax [Ω]
Safety Factor SF
13
4
20
60
80
270
8200
> 40
12
0
8,2
8,2
13
4
30
70
90
230
> 10000
> 40
10
0
10
12
14
3
30
80
100
121
> 10000
> 40
8
0
15
22
15
3
35
80
100
140
> 10000
> 40
6
0
15
22
14
3
35
80
140
170
> 10000
> 40
5
0
15
22
18
3
35
80
140
120
> 10000
> 40
4
0
15
22
16
4
20
80
150
80
> 10000
> 40
36 of 45
R1max (TK) [Ω]
4,7
R1max [Ω]
4,7
R1typ [Ω]
CX2 [pF] (Output)
0
C0typ [pF]
CX1 [pF] (Input)
16
CL [pF]
RX2 [Ω]
Quartz Crystal Data
Frequency [MHz]
External Circuits
AP242005 07.99
Crystal Oscillators of the
C500 / C166 Microcontroller Family
12.4 C166 Family: Type_LP2 Oscillator-Inverter
The table below contains the recommendations for the external circuitry using a Type_LP2
oscillator-inverter in fundamental mode. The quartz crystal data are included which are necessary
for the calculation of the drive level (PW) and Safety Factor (SF). The quartz crystal data are related
to the quartz crystals of appendix Quartz Crystals. The measured values of RQmax and the
calculated values of PW and SF are based on these quartz crystals and the formulas presented in
this ApNote.
Table 18
C166 Family Derivatives including a Type_LP2 Oscillator-Inverter
Device
Step
Oscillator Frequency
SAx-C161CI
AA, AB, BA, BB
4 - 16 MHz
SAx-C161RI
BA, BB
4 - 16 MHz
SAx-C161JI
AC, BA, CA
4 - 16 MHz
SAx-C161OR
FA
4 - 16 MHz
SAx-C164CI
BA, BC, CA
4 - 16 MHz
AB, AC, AD, AE, BA, BB
4 - 16 MHz
SAx-C167CS-32FM
Table 19
Recommendations for external circuitry used with a Type_LP2 Oscillator-Inverter in
Fundamental Mode
Fundamental Mode:
Type_LP2 Oscillator-Inverter
PW [µW]
(@ 25°C, R1typ)
RQmax [Ω]
Safety Factor SF
13
4
20
60
80
150
1200
8,77
12
0
3,3
4,7
13
4
30
70
90
110
2200
14,29
10
0
4,7
8,2
14
3
30
80
100
120
2200
14,92
8
0
5,6
12
15
3
35
80
100
100
3300
22,92
6
0
8,2
15
14
3
35
80
140
130
4700
22,77
37 of 45
R1max (TK) [Ω]
2,7
R1max [Ω]
2,7
R1typ [Ω]
CX2 [pF] (Output)
0
C0typ [pF]
CX1 [pF] (Input)
16
CL [pF]
RX2 [Ω]
Quartz Crystal Data
Frequency [MHz]
External Circuits
AP242005 07.99
Crystal Oscillators of the
C500 / C166 Microcontroller Family
Table 19
Recommendations for external circuitry used with a Type_LP2 Oscillator-Inverter in
Fundamental Mode
Fundamental Mode:
Type_LP2 Oscillator-Inverter
Safety Factor SF
35
80
140
80
5600
29,39
4
0
12
22
16
4
20
80
150
60
6800
29,01
38 of 45
R1max (TK) [Ω]
3
R1max [Ω]
18
R1typ [Ω]
18
C0typ [pF]
10
CL [pF]
0
CX1 [pF] (Input)
5
RX2 [Ω]
RQmax [Ω]
Quartz Crystal Data
PW [µW]
(@ 25°C, R1typ)
CX2 [pF] (Output)
Frequency [MHz]
External Circuits
AP242005 07.99
Crystal Oscillators of the
C500 / C166 Microcontroller Family
12.5 C166 Family: Type_RTC1 Oscillator-Inverter
The table below contains the recommendations for the external circuitry using a Type_RTC1
oscillator-inverter in fundamental mode. The quartz crystal data are included which are necessary
for the calculation of the Safety Factor (SF). The quartz crystal data are related to the quartz crystals
of appendix Quartz Crystals. The measured value of RQmax and the calculated value of SF are
based on these quartz crystals and the formulas presented in this ApNote.
Table 20
C166 Family Derivatives including a Type_RTC1 Oscillator-Inverter
Device
SAx-C161CI
Step
Oscillator Frequency
XTAL3
XTAL4
AA, AB
32 kHz ± 50%
Input (CX1)
Output (CX2)
Table 21
Recommendations for external circuitry used with a RTC1 Oscillator-Inverter in
Fundamental Mode
Type_RTC1 Oscillator-Inverter
1)
Safety Factor SF
1
RQmax [Ω]
12,5
R1max (TK) [Ω]
33
R1max [Ω]
33
CX2 [pF] (Output)
CX1 [pF] (Input)
Rf [MΩ]
no1)
C0typ [pF]
0
Quartz Crystal Data
CL [pF]
32,768
RX2 [Ω]
Frequency [kHz]
External Circuits
R1typ [Ω]
Fundamental Mode:
12000
35000
35000
330000
8,08
The Type_RTC1 oscillator-inverter requires no external feedback resistor.
39 of 45
AP242005 07.99
Crystal Oscillators of the
C500 / C166 Microcontroller Family
12.6 C166 Family: Type_RTC2 Oscillator-Inverter
The table below contains the recommendations for the external circuitry using a Type_RTC2
oscillator-inverter in fundamental mode. The quartz crystal data are included which are necessary
for the calculation of the Safety Factor (SF). The quartz crystal data are related to the quartz crystals
of appendix Quartz Crystals. The measured value of RQmax and the calculated value of SF are
based on these quartz crystals and the formulas presented in this ApNote.
Table 22
C166 Family Derivatives including a Type_RTC2 Oscillator-Inverter
Device
Step
Oscillator Frequency
XTAL3
XTAL4
SAx-C161CI
BA, BB
32 kHz ± 50%
Input (CX1)
Output (CX2)
SAx-C161JI
AC, BA, CA
32 kHz ± 50%
Input (CX1)
Output (CX2)
Table 23
Recommendations for external circuitry used with a RTC2 Oscillator-Inverter in
Fundamental Mode
Type_RTC2 Oscillator-Inverter
1)
Safety Factor SF
1
RQmax [Ω]
12,5
R1max (TK) [Ω]
2,7
R1max [Ω]
2,7
CX2 [pF] (Output)
CX1 [pF] (Input)
Rf [MΩ] 1)
6,8
C0typ [pF]
0
Quartz Crystal Data
CL [pF]
32,768
RX2 [Ω]
Frequency [kHz]
External Circuits
R1typ [Ω]
Fundamental Mode:
12000
35000
35000
180000
3,8
The Type_RTC2 oscillator-inverter requires an external feedback resistor Rf connected between
XTAL3 and XTAL4.
40 of 45
AP242005 07.99
Crystal Oscillators of the
C500 / C166 Microcontroller Family
13
Quartz Crystals for the C500 and C166 Family
13.1 Fundamental Mode Quartz Crystal for Standard Temperature Range
Table 24
Quartz Crystals for all Oscillator-Inverter used in Fundamental Mode
Standard Temperature Range from - 20°C to 70°C
Quartz Crystal Specification for Fundamental Mode:
HC49
HC52
Frequency
[MHz]
Can hight
6.6mm
low profile SH66
Can hight 13.5mm
SMD-Mounting
with Clip CS20
Can hight
8.8mm
StandardEnclosure
Can hight 8.8mm
SMD-Mounting
with Clip CS10
40
C167CR40
C167CR40S
C167CR40A
C167CR40AS
32
C167CR32
C167CR32S
C167CR32A
C167CR32AS
24
C167CR24
C167CR24S
C167CR24A
C167CR24AS
20
C167CR20
C167CR20S
C167CR20A
C167CR20AS
18
C167CR18
C167CR18S
C167CR18A
C167CR18AS
16
C167CR16
C167CR16S
C167CR16A
C167CR16AS
12
C167CR12
C167CR12S
C167CR12A
C167CR12AS
10
C167CR10
C167CR10S
C167CR10A
C167CR10AS
8
C167CR08
C167CR08S
C167CR08A
C167CR08AS
6
C167CR06
C167CR06S
C167CR06A
C167CR06AS
5
C167CR05
C167CR05S
C167CR05A
C167CR05AS
4
---
C167CR04S
---
---
The specifications C167CRxxxx are for the use in standard temperature range from
- 20°C to 70°C.
For further information please contact your local Tele Quarz Group sales office.
41 of 45
AP242005 07.99
Crystal Oscillators of the
C500 / C166 Microcontroller Family
13.2 Fundamental Mode Quartz Crystal for Advanced Temperature Range
Table 25
Quartz Crystals for all Oscillator-Inverter used in Fundamental Mode
Advanced Temperature Range from - 40°C to 125°C for Automotive Applications
Quartz Crystal Specification for Fundamental Mode:
HC49
HC52
Frequency
[MHz]
Can hight
6.6mm
low profile SH66
Can hight 13.5mm
SMD-Mounting
with Clip CS20
Can hight
8.8mm
StandardEnclosure
Can hight 8.8mm
SMD-Mounting
with Clip CS10
20
KFZ0010
KFZ0010S
KFZ0010A
KFZ0010AS
18
KFZ0011
KFZ0011S
KFZ0011A
KFZ0011AS
16
KFZ0012
KFZ0012S
KFZ0012A
KFZ0012AS
12
KFZ0013
KFZ0013S
KFZ0013A
KFZ0013AS
10
KFZ0014
KFZ0014S
KFZ0014A
KFZ0014AS
8
KFZ0015
KFZ0015S
KFZ0015A
KFZ0015AS
6
KFZ0016
KFZ0016S
KFZ0016A
KFZ0016AS
5
KFZ0017
KFZ0017S
KFZ0017A
KFZ0017AS
4
---
KFZ0018S
---
---
The specifications KFZ00xxxx are for the use in advanced temperature range from
- 40°C to 125°C for automotive applications.
For further information please contact your local Tele Quarz Group sales office.
42 of 45
AP242005 07.99
Crystal Oscillators of the
C500 / C166 Microcontroller Family
13.3 3rd Overtone Mode Quartz Crystal for Standard Temperature Range
Table 26
Quartz Crystals for all Oscillator-Inverter used in 3rd Overtone Mode
Standard Temperature Range from - 20°C to 70°C
Quartz Crystal Specification for 3rd Overtone Mode:
HC49
HC52
Frequency
[MHz]
Can hight
6.6mm
low profile SH66
Can hight 13.5mm
SMD-Mounting
with Clip CS20
Can hight
8.8mm
StandardEnclosure
Can hight 8.8mm
SMD-Mounting
with Clip CS10
40
---
C167CR403S
C167CR403A
C167CR403AS
The specifications C167CR403xx are for the use in standard temperature range from
- 20°C to 70°C.
For further information please contact your local Tele Quarz Group sales office.
13.4 3rd Overtone Mode Quartz Crystal for Advanced Temperature Range
Table 27
Quartz Crystals for all Oscillator-Inverter used in 3rd Overtone Mode
Advanced Temperature Range from - 40°C to 125°C for Automotive Applications
Quartz Crystal Specification for 3rd Overtone Mode:
HC49
HC52
Frequency
[MHz]
Can hight
6.6mm
low profile SH66
Can hight 13.5mm
SMD-Mounting
with Clip CS20
Can hight
8.8mm
StandardEnclosure
Can hight 8.8mm
SMD-Mounting
with Clip CS10
40
---
KFZ0009S
KFZ0009A
KFZ0009AS
The specifications KFZ0009xx are for the use in advanced temperature range from
- 40°C to 125°C for automotive applications.
For further information please contact your local Tele Quarz Group sales office.
43 of 45
AP242005 07.99
Crystal Oscillators of the
C500 / C166 Microcontroller Family
13.5 Real Time Clock Quartz Crystal
Table 28
Quartz Crystals for RTC Oscillator-Inverter used in Fundamental Mode
Standard Temperature Range from - 20°C to 70°C
Quartz Crystal Specification for Fundamental Mode:
Frequency [kHz]
Ordering Code
32.768
TC38 12,5
For further information please contact your local Tele Quarz Group sales office.
Table 29
Quartz Crystals for RTC Oscillator-Inverter used in Fundamental Mode
Advanced Temperature Range from - 40°C to 85°C
Quartz Crystal Specification for Fundamental Mode:
Frequency [kHz]
Ordering Code
32.768
TQEC45
32.768
TQEC46
32.768
TPSM32A
32.768
TPSM32B
For further information please contact your local Tele Quarz Group sales office.
44 of 45
AP242005 07.99
Crystal Oscillators of the
C500 / C166 Microcontroller Family
14
TELE QUARZ GROUP Sales Offices
For more information on TELE QUARZ GROUP
please call your local TELE QUARZ GROUP sales office.
Germany:
Germany:
TELE QUARZ GmbH
Landstrasse
D-74924 Neckarbischofsheim
Tel.: 49/7268/801-0
Fax : 49/7268/801-281
e-mail : [email protected]
TELE QUARZ GROUP
Vertriebsbüro Nürnberg
Landgrabenstrasse 32
D-90443 Nürnberg
Tel.: 49/911/42341-0
Fax : 49/911/421050
France:
United States:
Laboratoires de Piézo-Electricité (LPE) S.A.
Rue de Rome, Bat. Jean Monnet
F - 93110 Rosny Sous Bois
Tel.: 33/148 12 25 30
Fax : 33/148 12 25 39
Oak Frequency Control Group
100 Watts Street
Mt. Holly Springs, PA 17065
Tel.: (717) 486 3411
Fax : (717) 486 5920
Taiwan:
Japan:
TELE QUARZ Taiwan Corp.
2F No.82, Sec. 1 Hsin Hai Road
Taipei ROC
Tel.: +2-363 8688
Fax : +2-363 8887
Teletec Corporation
Yoshizawa Building 202
873-11 Kamiochiai, Yono City
Saitama Pref. 338
Tel.: +48-853 1270
Fax : +48-853-1393
United Kingdom:
Tele Quarz
9 Dean Street
Marlow, Bucks SL7 3AA
Tel.: +44 (1628) 474710
Fax : +44 (1628) 474810
45 of 45
AP242005 07.99
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