Card reading circuit and card reader

Abstract

The invention provides a card reading circuit and a card reader, wherein the circuit comprises a data card interface chip and a switch module; the switch module comprises a card seat connector, first to third resistors, a first MOS tube and a second MOS tube; the card seat connector and the data card chip both comprise I / O ends; the first to third resistors all comprise first ends and second ends; the first and second MOS tubes both comprise grid electrodes, drain electrodes and source electrodes; and the data card interface chip can normally send data to external processor end through connection of the card seat connector, the resistor and the MOS tube so as to realize reading and writing of I2C card.

Description

technical field

[0001] The invention relates to the field of a card reading circuit, in particular to a card reading circuit and a card reader. Background technique

[0002] With the development of science and technology, there are various data cards in the market, which are widely used in places such as hotels, hotels, and buses, such as CPU cards or I2C cards. The IC card interface chip for communication and master-slave switching transmission cannot effectively read the I2C card. Although the existing IC card interface chip for SPI / I2C / parallel port transmission can read the I2C card, the unit price is relatively high and practical. low performance; the existing IC card interface chip, its I / O end adopts the mode of rising edge switching master-slave trigger, there is a phenomenon that I2C card cannot be read, so a kind of IC card interface based on existing The chip, the circuit that reads the I2C card, makes it compatible to read the data card. Contents of the invent...

Examples

Embodiment Construction

[0015] In order to describe the technical content, structural features, achieved goals and effects of the present invention in detail, the following will be described in detail in conjunction with the embodiments and accompanying drawings.

[0016] see figure 1 and figure 2 , the present invention provides a card reading circuit, including a data card interface chip and a switch module, the switch module includes a card socket connector, a first resistor to a third resistor, a first MOS tube, a second MOS tube, the Both the card socket connector and the data card interface chip include I / O terminals; one end of the first resistor is connected to the I / O terminal of the card socket connector, and the other end of the first resistor is connected to the I / O terminal of the card socket connector. The drain of the first MOS transistor is connected; the source of the first MOS transistor is connected to the source of the second MOS transistor, and the common point of connection is...

technical field

[0001] The invention relates to the field of a card reading circuit, in particular to a card reading circuit and a card reader. Background technique

[0002] With the development of science and technology, there are various data cards in the market, which are widely used in places such as hotels, hotels, and buses, such as CPU cards or I2C cards. The IC card interface chip for communication and master-slave switching transmission cannot effectively read the I2C card. Although the existing IC card interface chip for SPI / I2C / parallel port transmission can read the I2C card, the unit price is relatively high and practical. low performance; the existing IC card interface chip, its I / O end adopts the mode of rising edge switching master-slave trigger, there is a phenomenon that I2C card cannot be read, so a kind of IC card interface based on existing The chip, the circuit that reads the I2C card, makes it compatible to read the data card. Contents of the invent...

Examples

Embodiment Construction

[0015] In order to describe the technical content, structural features, achieved goals and effects of the present invention in detail, the following will be described in detail in conjunction with the embodiments and accompanying drawings.

[0016] see figure 1 and figure 2 , the present invention provides a card reading circuit, including a data card interface chip and a switch module, the switch module includes a card socket connector, a first resistor to a third resistor, a first MOS tube, a second MOS tube, the Both the card socket connector and the data card interface chip include I / O terminals; one end of the first resistor is connected to the I / O terminal of the card socket connector, and the other end of the first resistor is connected to the I / O terminal of the card socket connector. The drain of the first MOS transistor is connected; the source of the first MOS transistor is connected to the source of the second MOS transistor, and the common point of connection is...

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