CN102970026A

CN102970026A - Mode selection circuit

Info

Publication number: CN102970026A
Application number: CN2012104760315A
Authority: CN
Inventors: 谢卫国
Original assignee: JIANGSU GELITE ELECTRONICS CO Ltd
Current assignee: JIANGSU GELITE ELECTRONICS CO Ltd
Priority date: 2012-11-22
Filing date: 2012-11-22
Publication date: 2013-03-13

Abstract

The invention discloses a mode selection circuit, and relates to the technical field of integrated circuits. The mode selection circuit comprises an internal model selective circuit of a chip and a pin of the chip, wherein the exterior of the pin is grounded through a resistor; and the interior of the pin is connected with an internal model selecting circuit through a switching circuit, and a connecting point of the interior of the pin and the switching circuit is connected with a power supply through a resistor and a MOS(metal oxide semiconductor) pipe which are connected in series. For the mode selection circuit provided by the invention, only one pin is used, one resistor which is connected with the exterior of the pin is added, and an AD switching circuit is used for replacing a logic control circuit; and the mode selection circuit realizes the selection of chips which integrate multiple modes among different modes through adjusting the resistance value of the resistor which is connected with the exterior of the pin, a pin resource of the chip is fully utilized, the chip cost is effectively reduced, the chip integration mode is more, and the effect is more obvious.

Description

A kind of mode selection circuit

Technical field

The present invention relates to the integrated circuit (IC) design field, be specifically related to a kind of mode selection circuit.

Background technology

In the chip of infrared remote controller, along with industry competition is more and more fierce, when requiring workinprocess cost more and more lower, chip needs the pattern of integrated a plurality of patterns available, but the mode selection circuit of prior art needs number of pins and pattern quantity to equate, take mode selection circuit shown in Figure 1 as example, and the integrated chip of 4 kinds of patterns, need 4 pins of encapsulation, select module to be connected to come implementation pattern to select by logic control circuit and internal schema; But the number of pins of chip is more, and the cost of chip is higher, and the chip normal operation time only is under a kind of pattern, and pin corresponding to other patterns is in idle state, is a kind of waste to resources of chip; Therefore must reduce the number of pin of encapsulation.

Summary of the invention

The technical problem to be solved in the present invention provides a kind of mode selection circuit, can solve multi-mode chip in the prior art and need to encapsulate the respective amount pin and cause chip cost to improve and the problem of waste resources of chip.

The present invention is achieved through the following technical solutions:

A kind of mode selection circuit, comprise the internal schema selection circuit of chip and the pin of chip, grounding through resistance is passed through in described pin outside, described pin inside selects circuit to link to each other by change-over circuit and internal schema, and described pin inside links to each other with power supply with switching tube by the resistance of connecting with the tie point of change-over circuit.

The further improvement of the present invention scheme is that change-over circuit is A/D convertor circuit, voltage signal is converted to the digital signal of model selection.

The further improvement of the present invention scheme is, switching tube is enhancement mode PMOS pipe, and the drain electrode of described enhancement mode PMOS pipe links to each other with resistance, and source electrode links to each other with power supply, and grid passes through interface CON and links to each other with outside start-up circuit.

The further improvement of the present invention scheme is, switching tube is NPN type triode, and the emitter of described NPN type triode links to each other with resistance, and collector electrode links to each other with power supply, and base stage links to each other with outside start-up circuit by interface CON.

The present invention's advantage compared with prior art is:

Only need to use 1 pin, increase the outside resistance that connects of 1 pin, replace logic control circuit with A/D convertor circuit, by adjusting the resistance of the outside contact resistance of pin, just can realize the selection of multimodal chip between different mode integrated, take full advantage of the pin resource of chip, effectively reduce chip cost, and the pattern of integrated chip is more, and effect is more obvious.

Description of drawings

Fig. 1 is the circuit structure diagram of the mode selection circuit of prior art.

Fig. 2 is the circuit structure diagram of mode selection circuit embodiment 1 of the present invention.

Fig. 3 is the circuit structure diagram of mode selection circuit embodiment 2 of the present invention.

Embodiment

Embodiment 1

A kind of mode selection circuit as shown in Figure 2, comprise the internal schema selection circuit 1 of chip and the pin two of chip, described pin two is outside by resistance 3 ground connection, described pin two is inner selects circuit 1 to link to each other by change-over circuit 6 and internal schema, and described pin two inside links to each other with power supply with switching tube 5 by the resistance 4 of connecting with the tie point of change-over circuit 6.

As shown in Figure 2, change-over circuit 6 is A/D convertor circuit, voltage signal is converted to the digital signal of model selection.

As shown in Figure 2, switching tube 5 is enhancement mode PMOS pipe, and the drain electrode of described enhancement mode PMOS pipe links to each other with resistance 4, and source electrode links to each other with power supply, and grid links to each other with outside start-up circuit by interface CON.

In the time of chip operation, the conducting after grid receives enabling signal of enhancement mode PMOS pipe 5, make the 4 place branch road conductings of resistance 3 and resistance form bleeder circuits, its partial pressure value is converted to digital signal corresponding to the pattern of integrated chip through A/D convertor circuit, exports infrared signaling signal.

Embodiment 2

As shown in Figure 3, compare with embodiment 1, the difference of embodiment 2 is: switching tube 5 is NPN type triode, and the emitter of described NPN type triode links to each other with resistance 4, and collector electrode links to each other with power supply, and base stage links to each other with outside start-up circuit by interface CON.In the time of chip operation, the conducting after base stage receives enabling signal of NPN type triode, make the 4 place branch road conductings of resistance 3 and resistance form bleeder circuits, its partial pressure value is converted to digital signal corresponding to the pattern of integrated chip through A/D convertor circuit, exports infrared signaling signal.

Claims

1. mode selection circuit, comprise the internal schema selection circuit (1) of chip and the pin (2) of chip, it is characterized in that: described pin (2) is outside by resistance (3) ground connection, described pin (2) inside links to each other by change-over circuit (6) and the inner circuit (1) of selecting, and described pin (2) is inner to link to each other with power supply with switching tube (5) by the resistance (4) of connecting with the tie point of change-over circuit (6).

2. a kind of mode selection circuit as claimed in claim 1, it is characterized in that: described change-over circuit (6) is A/D convertor circuit, voltage signal is converted to the digital signal of model selection.

3. a kind of mode selection circuit as claimed in claim 1, it is characterized in that: described switching tube (5) is enhancement mode PMOS pipe, the drain electrode of described enhancement mode PMOS pipe links to each other with resistance (4), and source electrode links to each other with power supply, and grid links to each other with outside start-up circuit by interface CON.

4. a kind of mode selection circuit as claimed in claim 1, it is characterized in that: described switching tube (5) is NPN type triode, the emitter of described NPN type triode links to each other with resistance (4), and collector electrode links to each other with power supply, and base stage links to each other with outside start-up circuit by interface CON.