JP4888802B2 - Semiconductor component design method - Google Patents

Description

  The present invention relates to a semiconductor component design method and a semiconductor component in which a semiconductor integrated circuit and a nonvolatile memory in which a setting value for determining an output voltage of the semiconductor integrated circuit is stored are formed monolithically. The present invention relates to a semiconductor component design method and a semiconductor component capable of coping with a change immediately and at low cost.

Recent electronic devices that require multiple functions are equipped with various circuits having different operating voltages, and require a plurality of power supply circuits corresponding to the respective operating voltages. In addition, for reasons such as cost reduction, the circuit to be mounted is often changed during development or after shipment, and it is necessary to change the supply voltage to the circuit accordingly. The output voltage of the power supply circuit can be changed by adjusting the value of the variable resistor of the regulator circuit, as shown in Patent Document 1, for example.
JP 2002-170391 A

  In general, specifications related to power supply circuits are often determined or changed later in product development, and it may be necessary to change setting values that determine power supply voltage after manufacturing a mask that builds resistors into a semiconductor wafer. Many. In order to cope with the change in the set value after the mask fabrication, it is necessary to change the mask, and a new mask must be recreated, which takes time and costs for mask fabrication along with recent miniaturization of semiconductor processes. However, the cost is high because of the high price. In recent years, various electronic devices are required to have multiple functions, but the development period is shortened and the cost is low, and it is desirable to deal with a sudden specification change immediately and at a low cost. .

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a semiconductor component design method and a semiconductor component that can be dealt with immediately and at a low cost even when a sudden specification change is required. There is.

Method for designing a semiconductor component of the present invention includes a semiconductor integrated circuit, a nonvolatile memory the set value is stored which determines the output voltage of the semiconductor integrated circuit is a method for designing a semiconductor component formed in a monolithic, the A first procedure for making a prototype of the semiconductor component in which a set value is adjusted to a provisional value, adjustment of the set value stored in a prototype of the semiconductor component, and evaluation of the output voltage are performed on the output voltage. It has the 2nd procedure performed in the state where the semiconductor part was connected to the load circuit which should be supplied, and the 3rd procedure which determines the set value based on the result of the evaluation .

The semiconductor component of the present invention is a semiconductor component in which a semiconductor integrated circuit and a nonvolatile memory in which a setting value for determining an output voltage of the semiconductor integrated circuit is stored are formed monolithically, and the supply of the output voltage The set value is determined based on the result of adjustment and evaluation performed in a state in which the semiconductor component is connected to a load circuit to be subjected to power .

Specifically, a manufacturer manufactures a semiconductor component with a semiconductor manufacturing apparatus. The user receives supply of semiconductor parts from the manufacturer, and uses the semiconductor parts as one part of the electronic device or as a single item. Then, the manufacturer supplies a prototype of the semiconductor component to the user. Here, in the prototype, the set value stored in the non-volatile memory and the output voltage determined by the set value are adjusted to a temporary value, and the value is not necessarily determined to be shipped as a product.

  The output voltage of the semiconductor component can be changed or fine-tuned by rewriting the set value stored in the non-volatile memory. Therefore, the user requests the manufacturer to recreate the output voltage even if the output voltage needs to be changed. Without this, the user can adjust the set value and change the output voltage to evaluate it. That is, the user does not need to request the manufacturer to change the specification or wait for supply of the prototype whose specification has been changed, and the user can freely change the specification. Therefore, the user can immediately perform the adjustment of the set value, and the user can also immediately evaluate the output voltage based on the adjustment, thereby shortening the development period. Furthermore, since the adjustment is realized by rewriting the set value in the nonvolatile memory, it is not necessary to redo the semiconductor manufacturing process by changing the mask as in the prior art, and the cost can be reduced.

  In parallel with the adjustment and evaluation by the user, the manufacturer also adjusts the set value to evaluate the output voltage, and determines the set value based on the evaluation result by the user and the evaluation result by the manufacturer. In this way, the manufacturer can make fine adjustments for accuracy so that the output voltage is within the allowable error range with respect to the user's desired set value, and the product quality can be improved.

  In addition, if the evaluation is performed with the semiconductor component connected to the load circuit that is to receive the output voltage supplied from the semiconductor integrated circuit, the user can cope with the variation in the required output voltage value due to the characteristics of the load circuit. Fine adjustments can be made to improve product quality.

  According to the method for designing a semiconductor component of the present invention, even if the necessity for a specification change occurs during development, it is not necessary for the manufacturer to recreate the semiconductor component in the semiconductor manufacturing process using the semiconductor manufacturing apparatus. Thus, the user can easily cope with the problem by changing the set value written in the nonvolatile memory, and the development period and cost of the semiconductor component can be shortened. In addition, the fact that the user can easily and quickly change the specifications of the semiconductor parts can easily and quickly change the specifications of the semiconductor parts already supplied by the manufacturer. That is, since the inventory can be utilized as a product with a new specification, useless inventory can be eliminated, and the cost can be greatly reduced.

  According to the semiconductor component of the present invention, even if the adjustment of the set value is repeated in determining the output voltage, the development period and the cost are not increased so much, and it is easy to perform trial and error in the design stage, and as a result, the product quality is improved. Can be achieved.

  FIG. 3 shows a circuit diagram of the semiconductor component 1 according to the embodiment of the present invention. The semiconductor component 1 includes a semiconductor integrated circuit 2 and a nonvolatile memory 7, which are monolithically formed on one semiconductor chip.

  The semiconductor integrated circuit 2 is a voltage regulator circuit, for example, and supplies a constant voltage to the load circuit 15a or the load circuit 15b. The semiconductor integrated circuit 2 includes a reference voltage generation source 3, a differential amplifier 4, a MOS (Metal Oxide Semiconductor) transistor 5, and a variable resistor 9.

  The reference voltage generation source 3 is connected to the inverting input terminal of the differential amplifier 4, and the reference voltage Vref from the reference voltage generation source 3 is input to the inverting input terminal of the differential amplifier 4. The output terminal of the differential amplifier 4 is connected to the gate of the MOS transistor 5.

  The source of the MOS transistor 5 is connected to the power supply 6, and a variable resistor 9 is connected between the drain and the ground. The drain of the MOS transistor 5 is connected to the output terminal 10 of the semiconductor component 1.

  The variable resistor 9 includes a plurality of (two in the illustrated example) resistors R 1 and R 2, and the dividing point is connected to the non-inverting input terminal of the differential amplifier 4. The reference voltage Vref is amplified by the differential amplifier 4, and the gate voltage of the MOS transistor 5 is controlled by the output. The resistance value of the variable resistor 9 determines the amplification factor in the differential amplifier 4.

  The nonvolatile memory 7 is a semiconductor memory that retains stored contents even when the power is turned off. For example, a mask ROM (Read Only Memory), a PROM (Programmable ROM), an EPROM (Erasable PROM), an EEPROM (Electrically EPROM), a flash Memory, NVRAM (Nonvolatile Random Access Memory), MRAM (Magnetic RAM), MONOS (Metal Oxide Nitride Oxide Semiconductor), etc. can be used.

  In the nonvolatile memory 7, the resistance value of the variable resistor 9, which is a setting value that determines the output voltage Vout of the semiconductor integrated circuit 2, is written and stored via the setting value input terminal 8 using an external device such as a writer. . The output voltage Vout is determined by the load circuit 15a or the load circuit 15b to be supplied with this voltage.

  Based on the set value stored in the nonvolatile memory 7, the resistance value of the variable resistor 9 is set. Specifically, based on the setting value stored in the non-volatile memory 7, which resistance division point of the variable resistor 9 is connected to the non-inverting input terminal of the differential amplifier 4 by, for example, a MOS switch (not shown) A selection is made.

  The set value is stored in the non-volatile memory 7 that remains stored even when the power is turned off, so that it is not necessary to newly write the set value every time the power is turned on. In addition, it is not necessary to mount a control unit that writes a set value every time the power is turned on in an electronic device on which the semiconductor component 1 is mounted, so that the cost can be reduced. Further, when diverting the CPU or the like originally mounted on the electronic device together with the semiconductor component 1 as the control unit, it is necessary to rewrite the farm. You can suppress the up.

  Next, a method for designing the semiconductor component 1 will be described with reference to the flowchart of FIG.

(Step S1)
First, the manufacturer of the semiconductor component 1 and the user of the semiconductor component 1 examine the specifications of the semiconductor component 1 (how much output voltage is required, how much accuracy is required, etc.).

  Here, the manufacturer has a manufacturing facility for the semiconductor component 1 and manufactures the semiconductor component 1 using the facility. The user needs the semiconductor component 1 as a component of an electronic device such as a mobile phone, an audio device, and a video device. For example, the semiconductor component 1 is used as another component mounted on an electronic device or a power supply component for a circuit. When the user receives the supply of the semiconductor component 1 from the manufacturer, the user mounts the electronic component on the electronic device and ships the electronic device as a product.

(Steps S2a, S3)
For example, when the specification is determined so that the output voltage Vout is 1.5 V ± 1% in the examination in step S1, the manufacturer adjusts the set value to be stored in the nonvolatile memory 7 so as to satisfy the specification. The semiconductor component 1 is prototyped. The set value adjusted in step S2a is stored in the prototype nonvolatile memory 7.

(Step S2b)
The manufacturer also provides the user with a writer for writing or erasing the set value in the nonvolatile memory 7. The writer may be supplied together when a prototype of the semiconductor component 1 is supplied to the user in step S3 described later. In addition, if the writer can use a general-purpose writer instead of a special one, and the user already has it or can easily prepare it by the user, it is not necessary to provide the writer from the manufacturer side. There is no.

(Step S4b)
The user receives supply of the prototype from the manufacturer. Then, the user evaluates the output voltage Vout of the prototype semiconductor component 1. That is, the output voltage Vout is evaluated by adjusting the set value that the user writes in the nonvolatile memory 7.

  Conventionally, when the output voltage Vout needs to be changed during the development before mass production of the semiconductor component 1, the request from the user who uses the semiconductor component 1 is communicated to the manufacturer to manufacture the semiconductor component 1. In response, the person has remade the semiconductor component 1 so that the output voltage Vout meets the requirement. This is accompanied by a change in resistance built into the semiconductor wafer, and a change in the mask for that purpose, which is time consuming, time consuming and costly.

  On the other hand, in the present embodiment, it is possible to cope with the change of the output voltage Vout only by rewriting the set value written in the nonvolatile memory 7. There is no need for the manufacturer to perform a semiconductor manufacturing process. Therefore, the user can easily change the specification (change the output voltage) and evaluate it without waiting for a prototype remade with a new specification from the manufacturer as in the past. As a result, the development period can be greatly shortened and the cost can be greatly reduced. It can respond quickly to sudden specification changes, and can easily respond to repeated specification changes.

  Also, the manufacturer does not have to remake the semiconductor parts to meet the user's requirements by changing the mask each time there is a specification change.

  Even if the output voltage Vout becomes a desired value, the output voltage Vout may need to be slightly changed depending on variations in the characteristics of the load circuit 15a or the load circuit 15b that receives the voltage supply. That is, it may not be known whether the output voltage Vout is appropriate unless the semiconductor component 1 is actually connected to the load circuit 15a or the load circuit 15b. In the present embodiment, the semiconductor component 1 and the load circuit 15a or the load circuit are not known. Since the user who is an electronic equipment manufacturer that performs the process of incorporating 15b into the electronic equipment adjusts the above set values and evaluates the output voltage Vout, the fine set values in accordance with the actual use of the semiconductor component 1 are set. Adjustment and output voltage Vout can be evaluated quickly and easily.

  In addition, in the prototype, for example, the semiconductor component 1 made as a power supply component for the load circuit 15a is changed to another load circuit 15b whose operating voltage is different from the load circuit 15a. The user can adjust the set value suitable for the load circuit 15b and evaluate the output voltage Vout quickly and easily without any interaction with the manufacturer.

(Step S4a)
In parallel with the above-described set value adjustment and output voltage evaluation on the user side, the manufacturer side may perform the set value adjustment and output voltage evaluation on the prototype. The user performs adjustments and evaluations mainly for output voltage changes accompanying load circuit changes, while the manufacturer performs the output voltage deviates from the desired value due to variations in the manufacturing process. In some cases, fine adjustment is made to keep the deviation within a certain range. For example, the adjustment performed by the user is an adjustment of which resistance dividing point in the variable resistor 9 is connected to the non-inverting input terminal of the differential amplifier 4, and the fine adjustment performed by the manufacturer constitutes the variable resistor 9. This is the adjustment of the volume of each resistor R1, R2.

(Steps S5a and S5b)
On the user side and the manufacturer side, the evaluation result of the output voltage Vout determined by the adjusted setting value is determined. If the evaluation result is not satisfactory, the manufacturer returns to step S2a, and the user returns to step S4b, and repeats the steps described above.

(Step S6)
If the evaluation results in the above steps S5a and S5b are satisfactory, the user connects the semiconductor component 1 to an actual load circuit that receives supply of power supply voltage from the semiconductor component 1 and connects the load circuit. Let's make it work and make a final evaluation.

  If the evaluation in step S6 is not satisfactory, the user returns to step S4b, or the manufacturer returns to step S2a, and repeats the steps described above.

(Step S7)
If the final judgment in step S6 is passed, the manufacturer mass-produces the semiconductor component 1 with the passed final specification. The final specification is obtained as a writer data file in which the final set value is written in the nonvolatile memory 7. Alternatively, the set value set as the final specification may be read from the nonvolatile memory 7.

(Step S8)
The user receives the supply of the semiconductor component 1 mass-produced from the manufacturer, assembles the semiconductor component 1 together with other components including the load circuit 15a or 15b, and ships the electronic device.

  Next, a flow for changing the set value when the necessity of changing the specification occurs after the electronic device is shipped will be described with reference to FIG.

(Step S101)
The user considers changing the mounted parts to meet the low cost requirements of electronic equipment. For example, it is assumed that a load circuit (for example, a semiconductor memory) 15a is mounted on an electronic device initially shipped, but there is a demand for changing to a load circuit (for example, a semiconductor memory) 15b that is cheaper than this. However, when the load circuit 15a operates at a voltage of 1.5V, for example, and the load circuit 15b operates at a voltage of 1.3V, for example, the output voltage Vout of the semiconductor component 1 must be changed. .

  Conventionally, it was possible to cope with the problem by changing the mask or the like and re-creating the semiconductor component 1, but this requires time and cost increase for the introduction of electronic devices with new specifications. Furthermore, in particular, electronic devices with a short life cycle in which new products and new models are developed one after another, such as mobile phones, have already been discontinued, and often cannot be remade.

  On the other hand, in the present embodiment, the output voltage can be changed easily and quickly by rewriting the set value of the nonvolatile memory 7 of the semiconductor component 1, so that the demand for the specification change after shipment of the electronic device can be easily met. I can do it. As a result, the load circuit can be switched to a cheaper one, and the cost of the entire electronic device can be reduced.

(Steps S102a and 102b)
The set value can be changed after shipment from the manufacturer side and the user side. The manufacturer trial manufactures the semiconductor component 1 in which a set value for determining an output voltage required for the load circuit 15b to be changed is written. The user side rewrites the set value of the semiconductor component 1 already supplied from the manufacturer side to a set value that determines the output voltage required by the load circuit 15b to be changed. Therefore, the user can utilize the semiconductor component 1 already supplied from the manufacturer with the specification before the change as a semiconductor component 1 with a new specification without wasting it.

(Step S103)
The user connects the changed load circuit 15b and the semiconductor component 1 whose output voltage has been changed for the load circuit 15b, and actually operates the load circuit 15b for evaluation.

(Step S104)
If the evaluation result in step S103 is satisfactory, the user determines the output voltage of the semiconductor component 1 and also determines the change of the load circuit mounted on the electronic apparatus together with the semiconductor component 1. And if final evaluation is performed and this is passed, it will progress to step S105a, S105b. If not satisfied, the process returns to step S101.

(Steps S105a and 105b)
In response to the final determination in step S104, the manufacturer mass-produces the semiconductor component 1 in which the changed setting value is written in the nonvolatile memory 7 and supplies it to the user. Alternatively, the user himself rewrites the set value in the nonvolatile memory 7 of the semiconductor component 1 supplied from the manufacturer.

(Step S106)
Finally, the user ships an electronic device equipped with the load circuit 15b that has been changed to a cheaper one and the semiconductor component 1 in which the output voltage has been changed in accordance with the load circuit 15b.

  As mentioned above, although embodiment of this invention was described, of course, this invention is not limited to this, A various deformation | transformation is possible based on the technical idea of this invention.

  The present invention is particularly suitable for the design of a power supply component that is mounted on a mobile phone that requires a short development period and requires low cost, and that is more likely to require a sudden specification change, but is not limited to this. The present invention can be applied to the design of power supply components mounted on electronic devices, and other semiconductor components as well as power supply components.

It is a flowchart (the 1) which shows the flow of the design method of the semiconductor component which concerns on embodiment of this invention. It is a flowchart (the 2) which shows the flow of the design method of the semiconductor component which concerns on embodiment of this invention. 1 is a circuit diagram of a semiconductor component according to an embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Semiconductor component, 2 ... Semiconductor integrated circuit, 4 ... Differential amplifier, 5 ... MOS transistor, 7 ... Nonvolatile memory, 9, R1, R2 ... Variable resistance, 15a, 15b ... Load circuit.

Claims (1)

A semiconductor integrated circuit having a plurality of variable resistors and having an output voltage set by selecting a predetermined combination of variable resistors from the plurality of variable resistors, and for setting an output voltage of the semiconductor integrated circuit A non-volatile memory in which a setting value that determines a combination of the variable resistors is stored is a monolithic semiconductor component design method,
A first procedure for prototyping the semiconductor component in which the set value is stored in the nonvolatile memory as a temporary value;
The adjustment of the setting value of the temporary value stored in the nonvolatile memory of the prototype of the semiconductor component and the evaluation of the output voltage are performed on the load circuit to be supplied with the output voltage. A second procedure to be performed in a connected state,
In parallel with the second procedure, the variable resistor of the prototype of the semiconductor component is used to suppress an error in the output voltage of the semiconductor component to be mass-produced with a final specification in the production line of the semiconductor component. A third procedure for adjusting the volume and evaluating the output voltage;
The volume of the variable resistor of the semiconductor component to be mass-produced in the final specification is determined based on the evaluation result in the third procedure, and the final is determined based on the evaluation result in the second procedure A fourth procedure for determining the set value stored as a final specification value in the nonvolatile memory of the semiconductor component to be mass-produced according to the specification.

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