JPS58210588A - Electronic timepiece capable of trimming - Google Patents

Abstract

PURPOSE:To drive an electronic timepiece with minimum necessary electric power by selecting a current limiting element and trimming the limit value of a current to a desired value. CONSTITUTION:N type MOS transistor (TR) 26a-26c forming current limiting elements applied with a bias voltage through a constnat voltage circuit 27 have mutually different saturation currents. When TRs 26a-26c are turned on selectuvely through switches 32a-32c, the current limit value of the oscillator 22 and frequency divider 23 of a timer circuit is trimmed to a desired value. Therefore, the electronic timepiece is driven with minimum necessary electric power according to variance of characterisitcs among constitutent elements.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a trimmable electronic timepiece, and more specifically, the present invention relates to a trimmable electronic timepiece, and more specifically, the present invention relates to an electronic timepiece that can be trimmed so that the power supplied to the main circuit section of the electronic hour hand consumes the minimum required stitches. Regarding watches.

In electronic watches, it is required to minimize the power consumed by the crystal oscillator circuit and the frequency divider circuit that divides the frequency of the oscillator output. In order to meet this demand, an electronic timepiece having the configuration shown in FIG. 1 has recently been proposed. The electronic watch 1 shown in FIG.
, and its output 4 connects the current limiting element 5,
The intersection 8 of the power supplies of the oscillation circuit 6 and the frequency division circuit 7 is connected to the curved end of the current limiting element 5, and the oscillation circuit 6 and the frequency division circuit 70 are connected to each other.
The power terminal is connected to the bent end 9 of the battery 2. The current limiting element 5 is made of MO8FET, and the 1 oscillation circuit 6.
is a P-channel MaS transistor and an N-channel M
Complementary type M formed by connecting OS transistors in series
Consists of OEI inverter.

Next, a tentative construction of the circuit shown in FIG. 1 will be explained. As shown in FIG. 2, the threshold voltage v'rp of the P-channel MOS transistor (not shown) constituting the inverter and the N-channel Mo8 transistor (
A heavy pressure V D is added to the threshold voltage VTN of the P-channel MOS transistor (not shown) and the heavy pressure Vo that turns on both the P-channel MOS transistor and the N-channel MO transistor (8).
2 or between it and the power supply line 8 shown in FIG. 1 is required at the start of oscillation.

η at the time of starting oscillation is expressed as pressure VT+2 by equation (1).

VD2 ≧ IV, TT'l - VT'
+Vo --tl) Once oscillation has started, the 11th equation of equation (1) becomes the relationship of equation (2). If the pressure to maintain lift is V'DI, then VD, ≧VDl≧ l Vrp I + VTN −
-------(21) Figure 3 shows the relationship between the source-drain voltage VD of the MOSFET and the drain level and current level when the current limiting element 5 in Figure 1 is configured with an MO8-FET. The voltage of the output 4 from the reference voltage circuit 5 in the figure is V
If it is a, then 8f! FIG. 5 shows the relationship between the source-drain voltage VDB and the drain current ID at that time. The heavy pressure applied to both ends 9 and 10 of the battery and battery 2 in Figure 1 is V
If DD, 'R (the electric current applied between one end 9 of the pond and the intersection 8, EF:, the voltage difference between V D and the city 1m voltage VDD is greater than or equal to the saturated source-drain voltage v8 of M O8 F ET In this case, a current of I flows at a constant level rather than a current through i4, and when it is lower than that, a current of ID27z flows which decreases as the source-drain voltage VIg decreases.

If VDD - VD > Vs, then = IDl constant value VDD - VD (from Va # # = I
D.

Variable Value Considering the point at which oscillation starts in Figure 1, the frequency divider circuit is not operating τ, so the current consumption of the frequency divider circuit at that time is I'D.
When it comes to IV, the value is extremely small.

Therefore, most of the maximum value IDI of the current flowing through the current limiting element can be used by the oscillation circuit. If the current of the oscillation circuit at the time of starting oscillation is l'osc, then IDI"
: I'oec holds true. If the voltage required to start excavation is a large difference between the power supply voltage VDD shown in Figure 3 and the saturated source-drain voltage VS of the MO-current limiting element, the power supply voltage shown in Figure 1 must be The voltage VD applied to one end 9 and the intersection 8 automatically decreases to a voltage vn2 required to start one oscillation.

At this time, the current flowing through the current limiting element 5 decreases as VD increases.

When using a complementary Mo8 inverter, the first condition for starting digging is η1, which satisfies the condition of applied %17 pressure. The second selling point is that the current required to start one oscillation satisfies the conditions, so the oscillation circuit 6
and the frequency dividing circuit 7 and the heavy pressure VD1, which satisfies the above two conditions, until the point of the force M +31 equation.

The mpressure VD increases and the current of the current limiting element decreases. K: Assuming the power product required to start oscillation, VD・ID
≧K The bias is automatically changed until (3) is satisfied.

If the voltage required to start excavation is less than the difference between the power supply voltage VDD and the source-drain voltage VS of the current limiting element, the saturation current of the current limiting element starts to oscillate.
', R, I' oθC and frequency divider circuit! fff, 工/n,
It is divided by v, and equation (4) is established.

IDI = I'o day a + 1'bl v ・= −
--When oscillation starts normally from f41 or above, the power and current V required for frequency division increase, the oscillation circuit current l6sc decreases, and the oscillation circuit current Iosc for excavation and maintenance stops. Since the sum of the frequency dividing circuit qv [yz and zo] at the time of firing does not change, +51. (The relationship of formulas 61 and +71 holds true.

IDI v >I'DI v ・・・・・・・・・
・・・・・・・・・・・・・・・(5) 工OSC）I'
osc ・・・・・・・・・・・・・・・・・・(6)I
Since DI = Iosc +, l v = I'osc +
I'DI v... (71) These operations are configured so that the current supplied by the current limiting element 5 is distributed by both the frequency divider circuit 7 and the oscillation circuit 6. We actively utilize the fact that the ratio of current required at the time of launch is different between the oscillation circuit and the frequency dividing circuit.Also,
Since this is not a method that controls voltage, the voltage applied to the oscillation circuit and frequency divider circuit is automatically varied and can be driven at the optimal voltage, so it is judged whether or not excavation has started, like in the voltage control method. There is no longer a need for a circuit to do this, and the operation is performed in open sea mode 1. Therefore, once stable operating conditions are set, stable operation can be maintained.

By the way, what are the constant voltage source 3 and the current limiting element 5?

For example, the circuit configuration shown in Fig. 4 is used, but when converting this circuit into a circuit, variations occur and the current/voltage characteristics shown in Fig. 5 deviate from the desired state, resulting in a divine malfunction. It has an intermediate point called arising. In particular, if there is variation in the magnitude of the current value Dl and the value of IDI exceeds the expected current range, the frequency divider circuit 7 may malfunction. l
If the IDI falls below the predetermined value of 1, the operation of the circuit will stop.

In addition, even if there is a person whose size ll)l is within the operable range of the circuit, it may not necessarily be possible to actually see the necessary minimum ηi force supply state with the arm V in steady motion,
In some cases, the purpose of adding such a power control circuit has been lost.

Therefore, the object of the present invention is to provide 'Ft(
To provide a trimmable electronic timepiece in which a current limit value can be kept within a desired range for trimming and a circuit can be operated with the minimum necessary power.

Hereinafter, the present invention will be explained in detail by means of illustrated embodiments.

FIG. 5 shows a block diagram of the 'rJi slave clock according to the present invention. Electronic clock 21 &, i, crystal excavation circuit 2
A 2° frequency dividing circuit 23 and an arithmetic display circuit 24 are provided, and one power supply terminal of each of these circuits is connected to a ten-pole terminal of a battery 25. In operation, the power terminals on all four sides of the display circuit 24 are grounded, while the power terminals of each region of the crystal excavation circuit 22 and frequency dividing circuit 25 are connected in common, and the N-channel MOS transistors 26a to 26c for current limiting are connected to each other. Connected to each drain. The sources of the MOS) run rasters 26a to 26c are commonly grounded, and the gates of the MOS run rasters 26a to 26c are commonly connected to the output line 28 of the constant voltage generating circuit 27.

The constant voltage generation circuit 27 consists of a detour type N-channel MOS transistor 29 and an enhancement type N-channel MO8) transistor 30, and the source of the MOS transistor 29 whose drain is connected to the ten-pole terminal of the transistor 25. and the gate are short-circuited, and connected to the MOS) run raster 300 gate and drain.M
The source of os transistor 6U is grounded) 11 MO
8) Constant Q generated at material connection point 61 of transistor 29.30
f juice will be generated in the output line 28 at the bias voltage EhVB and 1~.

The excavation circuit No. 2 and the frequency dividing circuit No. 2 are generated by the constant 71i pressure generating circuit 27 and the current limiting element consisting of an OS transistor.
The operation in which the force η supplied to 5 is automatically H
From Figures to Figure 4, it is exactly the same as Pierming j7/this.

If this supply gravity S circumferential operation reaches T-+ir as expected, one gate of the circuit can be closed by 4t by performing 1p1 operation with the lowest power. ■For the purpose of now,
The MOS transistors 26a to 26c during current limitation are
Each drain 1 when the drain-source open plane H- is saturated
@style IDa, ITlb, and IDc are designed to be different. Then, in order to be able to operate only any transistor among these five MOS transistors as a current limiting element, each drain circuit of the MOS transistors 26a to 26C is provided with a wiring section 52a for disconnecting the transistor. 35゛b,
56'c is provided, and by selectively disconnecting these wiring parts, only the transistor (R) can be used as a current limiting element, and the current limiting characteristics can be adjusted as desired. Therefore, circuit 22.2 can be configured using only one current limiting element.
However, even if there are variations in the characteristics of the current limiting element or voltage generating circuit 27 due to manufacturing reasons, it is possible to limit the current flowing through the wiring parts 32a, 32b, and 32c. , the combination of the current limiting element and the [TAQS used in 7] transistor'ff: change,
Minimum loss of Q without interfering with circuit operation
! , a combination of MOS transistors can be used to operate a circuit using power.

How to cut the wiring portions 52a to 52c is as follows.
This largely depends on each element in the IC manufacturing process, and is due to variations in the concentration of silicon impurities and the thickness of the acetylated film at that time. Therefore, as shown in FIG. 6, monitors 42a, 42b, 4
2c and 42d are provided in advance, and after all the steps are completed, evaluate using these monitors and separately prepare the wiring R13 in the item 1 that is necessary to set the IDI to the desired value. This cutting pattern may ultimately provide the desired tick.

”-8 Shijide sa↓, HP o S transistor 26a
, 26'b.

Each drain of 26c? We have described the method of wiring first and cutting off unnecessary parts later, but it is also possible to manufacture the drains of each MO8 transistor without wiring them in advance and make the desired connections after measuring with a monitor. Of course.

In this configuration, it is possible to trim the circuit so that the minimum amount of power is supplied to the operation of the circuit, which not only significantly improves the yield, but also allows for even if there are variations in characteristics during the manufacturing process. Power consumption and force can be easily suppressed to the minimum f10, and commercial quality circuit devices can be supplied at low cost and in a large size.

According to the present invention, as described above, even if there are variations in the characteristics of the device caused by the manufacturing process, trimming can
The power supply limit #1 value can be adjusted to a predetermined minimum level, and a high quality child clock can be obtained.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the configuration of a conventional electronic watch;
The figure is a graph showing the relationship between the input and output voltages of the crystal excavation circuit shown in Fig. 1, and Fig. 3 shows the relationship between the north-drain voltage VD8 of the current-limiting water element in Fig. 1 and the drain current. 4 is a circuit diagram showing a specific example of the current control circuit shown in FIG. 1, FIG. 5 is a block diagram showing the configuration of the electronic timepiece according to the present invention, and FIG. FIG. 2 is a plan view showing an example of a platform in which a monitor is provided on an IC wafer for a watch. 21...lr, child clock, 22...crystal excavation circuit, 25...frequency dividing circuit, 25...battery, 26
a, 26b, 26cm...N-channel MO8) transistor, 27...constant voltage generation circuit 1
．． 52a, 62b, 32c --- Wiring section, VB.
... Bias police, pressure. Applicant: Daini Seikosha Co., Ltd.

Claims (1)

[Claims] It is equipped with a plurality of MOS transistors that serve as current control elements, a circuit that supplies a constant bias voltage to these MOS transistors, and an oscillation/frequency dividing circuit, and is equipped with a plurality of MOS transistors that function as current control elements, a circuit that supplies a constant bias voltage to these MOS transistors, and an oscillation/frequency dividing circuit. Trimming 1J is characterized in that only 1' of the 1' side can be selectively connected to the power supply path of the pre-distribution shooting/frequency dividing circuit.
Functional electronic clock 0