EP2462489A2

EP2462489A2 - Electronic circuit for timer applications having minimal power consumption and methods for calibrating and operating the same

Info

Publication number: EP2462489A2
Application number: EP10731475A
Authority: EP
Inventors: Bertram KÖLBLI
Original assignee: Junghans Microtec GmbH
Current assignee: Junghans Microtec GmbH
Priority date: 2009-08-07
Filing date: 2010-07-07
Publication date: 2012-06-13
Also published as: SG177622A1; WO2011015266A3; WO2011015266A2; DE102009042647B4; DE102009042647A1

Abstract

The invention relates to a method for calibrating and to a method for operating an externally programmable electronic circuit, and to an externally programmable electronic circuit equipped to execute said methods. The externally programmable electronic circuit comprises a first oscillator (RCO) and at least one second oscillator (NFO), wherein the second frequency (1/T) of the second oscillator (NFO) is lower than the frequency (1/To) of the first oscillator (RCO). After a programmable time (t_P) has expired, the circuit brings about the execution of a predetermined action by outputting a corresponding output signal, wherein the programming is done by modulation of a carrier frequency (f_T). For calibration, the current period duration (T_O) of the first oscillator (RCO) and a ratio corresponding to the ratio between the period duration (T_O) of the first oscillator (RCO) and the period duration (T) of the second oscillator (NFO) are determined based on the known carrier frequency (f_T). During the operation of the circuit, the time (t_P) is programmed after or during calibration by way of modulation of the carrier frequency, wherein, after completion of the calibration and a start signal, the progression of the transmitted time (t_P) is such that a corresponding fourth periodicity (M-1) of the second oscillator (NFO) and a corresponding third periodicity (q) of the at most intermittently parallel operating first oscillator (RCO) are counted.

Description

Electronic circuit for timer applications smallest

Power consumption and method for calibration and operation thereof

The present invention relates to an externally programmable electronic circuit which, upon expiration of a programmable time, causes execution of a predetermined action by outputting a corresponding output signal, the programming being effected by modulation of a carrier frequency. The invention further relates to a method for calibration and a method for the

Operate such a circuit.

The above-mentioned electronic circuit, which is also referred to as electronic timer circuit and today usually has a microprocessor, is usually digitally programmed via an interface by means of an amplitude-modulated carrier frequency method. The high-precision carrier frequency used by an external programming device is quartz-stabilized. After programming such an electronic timer circuit, i. after, for example, inductive transmission and storage of the data for the passage of time in the microprocessor, a processor-internal or external start signal is given after a short pause, which represents the beginning of the expiration of the programmed time. After this time, a digital output signal is generated, which causes a further action. Such an electronic timer circuit is used, for example, in an ignition process.

There is now a need that the expiration of the programmed time should be very precise, although the microprocessor for other limiting reasons than

Timer for timing only one or more relatively inaccurate RC oscillators (Oscillator with RC element) are available. For example, with the passage of time only relative time errors of 100 ppm are allowed, whereas the frequency accuracy of today's RC oscillators is about 1 to 20%. From document DE 195 25 202 C1 a method for programming an electronic detonator is known, which achieves a high time accuracy. In the known method, a microprocessor-internal oscillator is used for calibration to the supplied by the external programmer quartz accurate carrier frequency, which is in the clock frequency by more than a power of ten over the external carrier frequency. Such a high clock frequency is common for the operation of a microprocessor, since this is also used to clock the command processing. In addition, the high clock rate is necessary to resolve the calibration interval, which forms the basis for the later time, with sufficient time. In the known method for calibration, the high-precision carrier frequency of the

Programmer in the electronic circuit up to a predetermined count and at the same time the relatively inaccurate oscillator frequency of the circuit counted. Upon reaching the predetermined count in relation to the high-precision carrier frequency reached with the inaccurate oscillator frequency count is stored as an internal time standard in the electronic circuit and the

Processing the programmed time used.

However, an on-going high processor clock, which is required in the above-described known methods, but generates a high power consumption of the processor. This is disadvantageous in the execution of the programmed time because the microprocessor is to be supplied during the programmed time not from a battery, but from capacitors or similar Energiespeichem low volume, which were charged during programming. It is therefore desirable that the power consumption of the microprocessor while maintaining the required maximum duration and the required

Drastically reduce accuracy.

The object of the present invention is therefore to provide an accurate electronic timer circuit whose current consumption is drastically reduced during the execution of the programmed time. Analog exists the

The object of the invention is to provide a method for calibrating an electronic circuit or a method for operating a programmable electronic circuit, which enable an exact sequence of a programmed time and at the same time bring about a reduction of the current consumption. The above object is achieved by an electronic circuit, which in addition to the first oscillator additionally comprises a second oscillator as a clock, wherein the frequency of the second oscillator is smaller than the frequency of the first oscillator. The electronic circuit furthermore has means for carrying out the calibration method explained below and for carrying out the method explained below for operating the circuit.

The above object is also achieved by a method for calibration, in which based on the known carrier frequency, the current period (T) of the first oscillator and a ratio corresponding to the ratio of the period of the first oscillator and the period of the second oscillator is determined ,

The electronic circuit according to the invention also realizes a method according to the invention for operating in which, after or during the calibration of the circuit, the time (t _P ) is determined by means of modulation of the circuit

Carrier frequency is programmed, wherein after completion of the calibration and a start signal, the expiration of the transmitted time takes place in that a corresponding fourth period number of the second oscillator and a corresponding third period number of at most temporarily working in parallel first oscillator are counted.

The present electronic circuit according to the invention and the methods according to the invention make use of the knowledge that the main cause of the high power consumption is the clock oscillator (first oscillator) and the associated speed of the clocking of the internal processor components. Because of the frequent need for reloading parasitic capacitances of the power consumption of the microprocessor increases largely linear with increasing clock frequency. This means that the clock frequency must be reduced in order to reduce the current consumption. This is achieved in the present invention through the use of the additional second processor-external low-frequency oscillator as the clock during the expiration of the programmed time. In a preferred embodiment, the clock frequency of the second oscillator is more than one order of magnitude lower than the external carrier frequency of the programmer to drive the power consumption of the circuit into the microampere range.

Although the use of the second oscillator with a low track frequency of the requirement for a precise timing or a high temporal - -

Contrasting resolution of the calibration interval, the required accuracy of the timer circuit is achieved at the end of the programmed time by the inventive combination of at most temporarily parallel oscillators operating at different frequencies and the inventive calibration.

According to the invention, it is assumed that the quartz-precise external carrier frequency is present for a short period of time before, during and after the digital time programming. This carrier frequency may, in a preferred embodiment, also be a carrier of energy to cover the entire circuit during and after the intermediate storage of the transmitted energy, e.g. in capacitors even after completion of programming to supply. In the short period of time during programming and the calibration of the timer circuit according to the invention by the inductive coupling with the programmer enough energy for the clocking of the processor with high

Clock frequency available. Thereafter, the circuit for the longest-lasting phase of the time-out occurs during the counting of the fourth period number of the second oscillator with the stored energy and is very frugal in the average power consumption.

In particular, an external RC oscillator or LC oscillator is provided according to the invention for the much longer phase of the expiration of the programmed time as a second oscillator, which operates at a very low clock frequency, preferably between about 1 kHz and about 10 kHz, for example 6 kHz, and during the majority of the time of the programmed time the clocking of the

Processor takes over. This oscillator (hereinafter referred to as NFO) has a very low current consumption, starts at the beginning of the initialization phase and remains switched on during all operating phases of the circuit according to the invention.

In contrast, the faster internal processor oscillator (hereinafter referred to as RCO) is turned on only during the calibration and the transmission of the programmed time and until the start of the timing and a short time beyond and at the end of the expiration of the programmed time. Here, the RCO serves as a reference and clock oscillator for the microprocessor and has a

Frequency of preferably about 1 MHz to about 5 MHz. During the majority of the time the programmed time has elapsed, the internal processor oscillator RCO is switched off. In a preferred method according to the invention for calibration first a first period number of the first oscillator RCO is counted up to a predetermined by the carrier frequency count corresponding to a predetermined time, and from this determines the ratio and thus the current period of the first oscillator, then with a Beginning edge of the second oscillator

NFO starting the periods of the first oscillator RCO counted in parallel further working second oscillator NFO until a first time, the first period number is reached, and then detects a next, occurring after the first time end edge of the second oscillator NFO whose direction in Compared to the initial edge can be determined, wherein in the

Period from the first time and until reaching the end edge, a second period number of the first oscillator RCO is counted, resulting in the ratio of the first period number and the second period number and the counted between the beginning and the end edge periods of the second oscillator.

This calibration method is a particularly simple method, which ensures that the expiration of the programmed time is comparatively accurate and, moreover, that the second oscillator NFO can be used as a clock during a large portion of the time during the execution of the programmed time.

A simple calculation of the period ratio described in the exemplary embodiments is made possible if, in a preferred embodiment, the starting edge and the trailing edge of the second oscillator NFO have the same direction and thus the ratio directly from between the

Beginning and trailing edge counted periods of the second oscillator NFO and the sum of the first and the second period number of the first oscillator RCO is determined. In a particularly preferred embodiment of the calibration method, the third period number of the first oscillator RCO and the fourth period number of the second oscillator NFO is calculated on the basis of the calculation method explained in more detail below. In a preferred embodiment of the method for operating an externally programmable electronic circuit, the third period number and the fourth period number are selected such that during the substantially largest time portion of the programmed time, the fourth period number of the periods of the - Second oscillator NFO is counted, wherein during the time portion of the first oscillator (RCO) is substantially turned off.

In a further preferred embodiment, the fourth period number is determined from the number of whole periods of the second oscillator, which are included in the transmitted or programmed time, less 1.

A particularly easy-to-implement sequence of the transmitted time is achieved in that after the start signal, first, when the first oscillator RCO and the second oscillator NFO are operating in parallel, a first sequence number of expired ones has elapsed

Periods of the first oscillator is counted, which is after the start signal until an edge of the second oscillator is reached, then the first oscillator RCO is turned off and the fourth period number of the periods of the second oscillator NFO until reaching the corresponding edge of the second oscillator NFO is counted down, after reaching the last-mentioned flank of the second oscillator NFO the first oscillator RCO is turned on again and finally the difference number of periods of the first oscillator RCO between the third period number determined in the calibration and the first sequence number is counted.

Further advantages, features and applications of the present invention will become apparent from the following description of an embodiment and the figures. All described and / or illustrated features alone or in any combination form the subject matter of the present invention, also independent of their

Summary in the claims or their back references.

1 shows an electronic circuit according to the present invention,

2 shows a representation of the temporally successive steps during calibration, programming and the course of the programmed time, FIG. 3 shows a first step in the calibration according to the invention of the electronic circuit according to FIG. 1, FIG.

4 shows a second step in the inventive calibration of the electronic circuit according to FIG. 1 and FIG Fig. 5 is an illustration of the inventive method for operating the electronic circuit according to. Figure 1 during the expiration of the programmed time.

Figure 1 shows the electronic circuit according to the invention with a microprocessor 1, which has the inputs A, B, C and D and the output F.

Further, an input Ub is provided on the microprocessor 1, which serves for voltage supply. The microprocessor 1 has an internal clock

(RC oscillator, short RCO), which provides a processor-internal high clock frequency of 2.4 MHz, for example. The microprocessor 1 also includes a timer 2 which is connected through a switch 3 to either the RCO or the input D (and thus to the NFO).

Component of the electronic circuit according to the invention is also a second oscillator (short NFO) with a lower compared to the RCO clock frequency, which is for example at 6 kHz. The NFO is not only connected to the external clock input D of the processor 1 but also in parallel with the port B of the microprocessor 1, so that via this input also a

Program counter control for a calibration can also be done on this clock. The connection to the inputs B and D of the microprocessor 1 is done only because in many processors the clock input D internally can not be used as a port or interrupt input.

In a further embodiment, a microprocessor can be used in which the clock input D can also be used as a port or interrupt input. In this case the parallel connection of the NFO with a separate port entrance is not necessary.

At the input A of the microprocessor 1 is in the programming of the circuit according to the invention to the quartz-accurate external carrier frequency. In a preferred embodiment, the carrier frequency may also be an energy source to power the entire circuit during and after programming. This case is shown in FIG. 1 by the dashed lines

Components shown. At the input C of the microprocessor 1, the signal for starting the lapse of the programmed time is input. - -

At the output F of the microprocessor 1, a predetermined signal is output after the programmed time that causes a further action, such as an ignition. FIG. 2 shows in the middle line the individual steps during initialization,

Calibration, programming, expiration of the programmed time and ends with the output of the defined signal to the output F of the microprocessor. In the upper line it can be seen which of the oscillators (RCO or NFO) is used as clock ('dock') for the microprocessor 1. Here, in the areas indicated by the reference numeral 11, the RCO

While in area 12 the oscillator is NFO clock. The lower line 13 in FIG. 2 symbolizes by its extent when the external carrier frequency is applied to the input A of the microprocessor 1 in the overlying steps.

After switching on the carrier frequency f _τ , which is for example 200 kHz and is not yet modulated initially, the supply of the circuit begins and in the first phase 21, the subsystems of the microprocessor 1 are initialized. The direction of the time progress is indicated by the arrow 10 in FIG.

In the subsequent phase 22, in which initially the programmer continues to transmit a non-modulated carrier frequency _f.sub.τ , a first calibration step, which is shown in more detail in FIG. 3, is carried out.

In this step 22, the processor 1 counts in a first count except for a predetermined known number of oscillations i of the quartz-precise carrier frequency f _τ at its input A, which correspond to a time of t _k = k ms (see row K in FIG. 3). In one embodiment, t _k = 8 ms. Simultaneously with the start of the first count, a second count is initiated by the integrated timer 2 of the microprocessor 1 (compare arrow 31 in FIG. 3). In the second count, the clocks of the RCO are counted until the predefined number of i carrier vibrations after the time t _{k is} reached (arrow 32). The counted during the time t _k RCO clocks with a period To over the time t _k are shown in Figure 3 in line L. The counter reading X of the timer 2 reached at the end of the second count is stored in a non-illustrated memory of the microprocessor 1 for further use. The count X corresponds to the time t _k) measured in RCO clocks, and the current period To of the first oscillator RCO can be determined from the ratio t _k / X. After this first calibration step 22, in a step 23, the programming of the transit time t _P as a digital word by modulation of the voltage applied to the input A of the microprocessor 1 carrier frequency f _τ . Here, the information for the time t _P is transmitted as a digital value and also in the not shown

Memory of the microprocessor 1 is stored.

In a further embodiment, the programming step 23 may also be performed before the first calibration step 22.

The programming step 23 is followed, according to the invention, by a second calibration step 24, which is shown in greater detail in FIG. Due to the execution of the previous first calibration step 22, the external carrier frequency is no longer needed for this step. It is therefore switched off in the course of step 24 (cf the end of line 13 in FIG.

In the second calibration step 24, the microprocessor 1, which is still clocked with the RCO frequency, first waits for a first count edge of the NFO clock, which is shown in line M in FIG. If this occurs (see arrow 33), two counts (third and fourth count) begin again. A program loop counts in a third count the NFO clocks fed to port B, while timer 2 counts the RCO clocks generated internally by the processor. Here, the NFO clocks are shown in Figure 4 in line M and the RCO clocks in Figure 4 in line N. Now reaches the timer 2 again the count X after the time t _k , a flag is set in the program (symbolized in Figure 4 by the arrows 34 and 35), which causes the occurring after the flag next count edge of the NFO clock after n NFO clocks serve as stopping or overriding criteria for the continued counting of the RCO clocks (see arrow 36). After step 24 there is thus an integer count n for the number of NFO clocks and the count X + Y, to which the timer 2 has counted the RCO clocks during the n NFO clocks. From this, the ratio V = n / (X + Y) can be determined.

From the existing counter readings and values, parameters M and q for the course of the programmed-in time t _P , which is shown in FIG. 5, can now be calculated in step 25 by the microprocessor 1, which is also clocked with the RCO frequency. The programmed time t _P , which is to take place before the output of the predefined signal at the output F of the microprocessor 1 and is for example integer in milliseconds, is first expressed by the calibration interval t _k : t _P = at _k + bt _k / k with a = t _p DIV k and b = t _P MOD k. (1 )

Here, t _P and k are assumed to be integers, which is why a and b become integers and b / k is always less than one. Now, in equation (1), if the calibration interval t _k is pressed by the NFO

Clock period T out, it follows that t _k = n (X / (X + Y)) T t _P = (a + b / k) n (X / (X + Y)) T = MT + FT (2), where M = INT ((at X + bn X / k) / (X + Y))) = INT (n X / (X + Y) (a + b / k))

= INT (V t _k / To (a + b / k)) and F = FRAC ((at X + bn X / k) / (X + Y)) = FRAC (V t _k / To (a + b / k)). Since F represents the fractional portion of an NFO clock period T, to obtain a higher propagation accuracy T for the second summand in (2) by means of the relationship To = n T / (X + Y), the NFO period T is calculated in integer values RCO clock period To: t _P = MT + FT = (M-1) T + (F + 1) T = (M-1) T + q To where q = (F + 1) (X + Y) / n (3) and q = (F + 1) / V.

In the equation (3), since the time qTo is always longer than one clock period T but shorter than 2 clock periods T, division into M-1 and F + 1 clock periods T has been made. This ensures that the time can be filled from the starting signal asynchronously occurring with the period T until the beginning of an NFO clock and the end of the execution phase according to Figure 5 always integer with q = p + (q - p) fast RCO clocks. As a result, a precise sequence of the programmed time t _{P is} achieved. In the lengthy mean time period of time elapse, exactly (M-1) NFO clocks are counted to save energy.

Now, after a pause 26 and triggered by a voltage applied to the input C of the microprocessor 1 start signal (symbolized by arrow 27 in Figure 2), the sequence of the programmed run time t _P , in Figure 2 by step 28 - 1 - is shown. After expiration of the programmed time t _P , the output of a predefined signal at the output F of the microprocessor 1, which causes a predetermined action. The output of the signal is shown by the arrow 29 in FIG.

The sequence of the programmed time t _P in FIG. 5 is illustrated in detail. Start 27 is generally asynchronous to the NFO clock, so that until the occurrence of the first count edge of the NFO clock (see arrow 41 in FIG. 5), RCO clocks are first counted by the internal timer (compare line Q in FIG. 5) , The counter reading p obtained with the first counting edge of the NFO clock, which for the above reason qTo> T must be even smaller than q, is stored in the memory of the microprocessor 1 and then the RCO clock is switched off. The state of the RCO is shown in line 42 of Figure 5, where "RCO on" means that the RCO is on, and "RCO off ', that the RCO is off.

Now, by the then connected to the NFO clock internal timer 2 exactly (M-1) NFO clock periods T are counted (see line P of Figure 5) and then by a Tim interrupt (symbolized by arrow 43) again the RCO switched on. This takes over again the timer timing by appropriate

Switching of the switch 3 for the remaining (q - p) RCO clocks until the end of the programmed runtime tp. In line 44 of FIG. 5 it is once again illustrated in which periods which period or clock frequency is decisive for the microprocessor, where To is the period of the RCO and T is the period of the NFO.

Since in the majority of the time (M-I) T, in which only the low-frequency NFO is turned on, the power consumption of the circuit according to the invention is very low, the power consumption of the entire assembly can be kept very low during the entire run of the programmed time tp.

To achieve a high runtime accuracy, the frequency tolerance of the oscillators NFO and RCO is irrelevant. Only a sufficient short-term stability of the output frequency of these oscillators is necessary, so that the frequencies during calibration and runtime match. For RC oscillators it is necessary to keep the temperature and power supply constant. However, this is generally achievable with simple means. LIST OF REFERENCE NUMBERS

I microprocessor

2 counter unit (timer)

3 switches

I 1 Time span in which the RCO clock is

12 Time span in which the NFO clock is

13 Time span in which the external carrier frequency is applied

21 Initialization phase

22 first calibration step

23 programming step

24 second calibration step

25 step for parameter calculation

26 break

27 start signal

28 Expiry of the programmed time

29 Output of the output signal through the microprocessor 1 42 line

44 line

10, 31, 32, 33, 34, 35, 36, 41, 43 arrow

A, B, C, D, Ub Inputs of the microprocessor 1

F output of the microprocessor 1

K Signal curve of the unmodulated carrier frequency

L, N, Q History of the RCO signal

M, P History of the NFO signal i preset count

n number of NFO oscillations

T Period of the NFO

To Period of the RCO

t _P programmed time

X, Y Period number of RCO periods

M Period number of NFO periods (or M-1)

q, p Period number of RCO periods

V ratio

Claims

claims

1. A method for calibrating an externally programmable electronic circuit having a first oscillator (RCO) and at least one second oscillator (NFO), wherein the second frequency (1 / T) of the second oscillator (NFO) is smaller than the first frequency (1 To the first oscillator (RCO), the circuit after completion of a programmable time (t _P ) by outputting a corresponding output signal causes the execution of a predetermined action, wherein the programming is carried out by modulation of a carrier frequency (f _τ ), wherein known carrier frequency (f _τ ), the current period (To) of the first oscillator (RCO) and a ratio (V), the ratio of the period (To) of the first oscillator (RCO) and the period (T) of the second oscillator ( NFO) is determined.

2. The method according to claim 1,

characterized in that

first a first period number (X) of the first oscillator (RCO) up to a predetermined by the carrier frequency (f _τ ) count (i) corresponding to a predetermined time (t _k ) counted, and from this the ratio (t _k / X ) and thus the current period duration (To) of the first oscillator (RCO) is determined, then with an initial edge of the second oscillator (NFO) starting the periods (To) of the first oscillator (RCO) in parallel further working second oscillator (NFO) so be counted until the first period number (X) is reached at a first time, and then a next, occurring after the first time end edge of the second oscillator (NFO) is detected, the direction of which is determinable compared to the initial edge, wherein in the Period starting with the first

Time and until the end edge is reached, a second period number (Y) of the first oscillator (RCO) is counted, whereby the ratio of the first period number (X) and the second period number (Y) and the periods counted between the start and end edges ( n) of the second oscillator (NFO).

3. The method according to claim 2,

characterized in that

the starting edge and the trailing edge of the second oscillator (NFO) have the same direction and thus the ratio (V) of n / (X ⁺ Y) is determined.

4. The method according to any one of the preceding claims,

characterized in that

the first frequency (1 / To) is about 1 to about 5 MHz and the second frequency (1 / T) is about 1 to about 10 kHz.

5. The method according to any one of claims 3 or 4,

characterized in that

for controlling the lapse of the programmed time (t _P ), a third period number (q) of the first oscillator (RCO) of q = {[FRAC (P)] + 1} / V and a fourth period number (M-1) of the second oscillator from M-1 = [INT (P)] -1, where P = V t _k / To (a + b / k) and a, b, k are integers.

6. A method of operating an externally programmable electronic circuit, which after a programmable time (t _P ) by outputting a corresponding output signal causes the execution of a predetermined action, wherein the programming is carried out by modulation of a high-precision carrier frequency, wherein the circuit is a first oscillator (RCO) and at least one second oscillator (NFO), wherein the second frequency (Ml) of the second oscillator (NFO) is less than the first frequency (1 / To) of the first oscillator (RCO), wherein after or during the calibration the circuit (t _P ) is programmed by means of the carrier frequency, wherein after completion of the calibration and a start signal, the expiration of the transmitted time (t _P ) is effected in that a corresponding fourth period number (M-1) of the second oscillator (NFO) and a corresponding third period number (q) of at most temporarily working in parallel first oscillator (RCO) are counted.

7. The method according to claim 6,

characterized in that

the third period number (q) and the fourth period number (M-1) are selected such that the periods (T) of the second oscillator (NFO) are counted over the substantially largest time proportion of the transmitted time (t _P ), during the course of the process the time portion of the first oscillator (RCO) is turned off.

8. The method according to any one of claims 6 to 7,

characterized in that

the fourth period number (M-1) of the number (M) of the whole periods (T) of the second oscillator (NFO) included in the programmed time (t _P ) is less

1 corresponds.

9. The method according to any one of claims 6 to 8,

characterized in that

the sequence of the transmitted time (t _P ) after the start signal takes place in such a way that first with first oscillator (RCO) and second oscillator (NFO) operating in parallel a first number of expires (p) of the elapsed periods (To) of the first oscillator (RCO) is counted is reached, which has elapsed after the start signal until an edge of the second oscillator (NFO) is reached, then the first oscillator (RCO) is turned off and the fourth period number of

Periods (T) of the second oscillator (NFO) is counted until reaching the corresponding edge of the second oscillator (NFO), after reaching the last edge of the first oscillator (RCO) is turned on again and finally the difference number (qp) of periods (To) of the first oscillator (RCO) between the third determined in the calibration

Period number (q) and the first sequence number (p) is counted.

10. Externally programmable electronic circuit having a first oscillator (RCO) and a second oscillator (NFO), wherein the second frequency (1 / T) of the second oscillator is smaller than the first frequency (1 / To) the first oscillator, the circuit being arranged to effect the execution of a predetermined action upon expiration of a programmable time (t _P ) by outputting a corresponding output signal, the programming being effected by modulation of a carrier frequency with which the circuit is activated during programming at least temporarily, wherein a counting unit, which is connectable to either the first oscillator (RCO) or the second oscillator (NFO), and means for performing any of the specified in the claims 1 to 5 method and means for performing one of the in the Claims 6 to 9 specified methods are provided.

11. Electronic circuit according to claim 10,

characterized in that

the first frequency (1 / To) is about 1 MHz to about 5 MHz and the second frequency (MT) is about 1 kHz to about 10 kHz.