CN201199349Y

CN201199349Y - Serial port level changer

Info

Publication number: CN201199349Y
Application number: CNU2008201019147U
Authority: CN
Inventors: 勾广辉
Original assignee: Fujian Centerm Information Co Ltd
Current assignee: Fujian Centerm Information Co Ltd
Priority date: 2008-04-11
Filing date: 2008-04-11
Publication date: 2009-02-25
Anticipated expiration: 2018-04-11

Abstract

The utility model provides a serial-port level translator, comprising a female connector for the D type 9-pin data interface, a male connector for the D type 9-pin data interface and a level conversion chip connected between the female and the male connectors for D type 9-pin data interface. The female connector for the D type 9-pin data interface is connected with a TTL serial port of an end host, and the male connector for the D type 9-pin data interface is connected with a peripheral device of a RS232 serial port. The TTL level input by the host ports is converted into RS232 level by a circuit designed with SP232 A chip as a main body. The serial-port level translator has the advantages that: the serial port for the TTL level signals is converted into the serial port of the RS232 level, and the TTL serial port of the end equipment is converted into the RS232 serial port for use, thus providing the peripheral device expansibility of the serial port for users in the industry of multi-serial ports application, and meeting the needs of industrial customers.

Description

The serial ports level translator

[technical field]

The utility model is about a kind of computer equipment, is meant a kind of serial ports level translator especially.

[background technology]

So-called Transistor-Transistor Logic level (transistor-transistor logic level), it exports high level〉2.4V, output low level＜0.4V.At room temperature, generally exporting high level is 3.5V, and output low level is 0.2V.Minimum input high level and low level: input high level 〉=2.0V, input low level＜=0.8V, noise margin is 0.4V.

The RS232 serial ports is present the most frequently used a kind of serial communication interface, full name is " serial binary data exchange interface technical standard between data terminal equipment (DTE) and the data communications equipment (DCE) ", and the voltage of the electrical specification of this interface any signal line in RS232 is the negative logic relation.That is: logical one ,-5--15V; Logical zero+5-+15V.Noise margin is 2V.Promptly require receiver to discern to be low to moderate+signal of 3V is as logical zero, and high signal to-3V is as logical one.

Owing to there is the serial ports of Transistor-Transistor Logic level than multiterminal end equipment, especially for a large amount of systems that use of many serial equipments such as postal service, bank, hold the serial ports quantity of Transistor-Transistor Logic level of last equipment more equally, yet existing more serial ports peripheral hardware all is the RS232 electric level interface, can cause holding the problem of the RS232 serial ports deficiency of last equipment like this, so, need a kind of TTL RS 232 serial ports level translator of design, to satisfy industry customer's demand at the problem of RS232 serial ports deficiency.

[summary of the invention]

Technical problem to be solved in the utility model is to provide a kind of serial ports level translator, and the TTL serial ports of the last equipment of end is converted into the RS232 serial ports by TTL RS 232 serial ports level translator, uses with the many serial ports that satisfy the industry customer.

The utility model solves the problems of the technologies described above by the following technical programs: a kind of serial ports level translator, comprise the D type data interface connector female of 9 pins, the D type data interface connector male of 9 pins, and be connected level transferring chip between the D type data interface connector male of the D type data interface connector female of 9 pins and 9 pins, the D type data interface connector female of described 9 pins is connected in the TTL serial ports of the last main frame of end, and the D type data interface connector male of 9 pins is connected in RS232 serial ports peripheral hardware.

This utility model can further be specially:

Described level transferring chip is SP232A.

2 pin of described level transferring chip SP232A are connected respectively to the D type data interface connector female of 9 pins by a

capacitor C

3 and 1 pin, 6 pin of male are connected respectively to the D type data interface connector female of 9 pins and 5 pin of male by a capacitor C 4 respectively, 2 pin of the D type data interface connector female of 9 pins and 12 pin and 11 pin that 3 pin are connected respectively to level transferring chip SP232A, 2 pin of the D type data interface connector male of 9 pins and 13 pin and 14 pin that 3 pin are connected respectively to level transferring chip SP232A.

The advantage of the utility model serial ports level translator is: the design of TTL RS 232 serial ports level translator is converted into the serial ports of Transistor-Transistor Logic level signal the serial ports of RS232 level, the TTL serial ports of the last equipment of end is converted into the RS232 serial ports to be used, the industry user who uses for many serial ports provides the extendability of serial ports peripheral hardware, has satisfied industry customer's demand.

[description of drawings]

The utility model will be further described in conjunction with the embodiments with reference to the accompanying drawings.

Fig. 1 is the annexation figure of the utility model serial ports level translator.

Fig. 2 is the internal circuit diagram of the utility model serial ports level translator.

[embodiment]

Please consult Fig. 1 simultaneously, the utility model serial ports level translator comprises DB9 (the D type data interface connectors of 9 pins) female 10, DB9 male 20, and is connected the level transferring chip 30 between DB9 female 10 and the DB9 male 20.

Described DB9 female 10 is connected in the TTL serial ports of the last main frame of end, and DB9 male 20 is connected in RS232 serial ports peripheral hardware.

Please consult Fig. 2 simultaneously, described level transferring chip 30 is SP232A, this serial ports level translator is that the circuit of body design is formed by level transferring chip SP232A promptly, 2 pin (V+) of this level transferring chip SP232A are connected respectively to 1 pin (VCC) of DB9 female 10 and DB9 male 20 by a

capacitor C

3,6 pin (V-) are connected respectively to 5 pin (GND) of DB9 female 10 and DB9 male 20 by a

capacitor C

4,2 pin (RXD of DB9 female 10, receive data) and 3 pin (TXD, send data) be connected respectively to the 12 pin (R1OUT of level transferring chip SP232A, receive 1 output) and 11 pin (T1IN, send 1 input), 2 pin of DB9 male 20 (RXD receives data) and 3 pin (TXD sends data) are connected respectively to the 13 pin (R1IN of level transferring chip SP232A, receive 1 input) and 14 pin (T1OUT sends 1 output).

During use, DB9 female 10 is connected in the serial ports of the last main frame of end, DB9 male 20 is connected in the serial ports peripheral hardware, then the power supply of this serial ports level translator internal circuit device by 1 pin of serial ports (DCD, carrier wave detects) provide+5V guarantees this circuit module operate as normal.This TTL RS 232 serial ports level translator only carries out level conversion to 2 pin (RXD receives data) and 3 pin (TXD sends data) of serial ports by internal circuit.

The Transistor-Transistor Logic level of input is by being that the circuit of body design realizes that Transistor-Transistor Logic level converts the RS232 level to SP232A, because the circuit of using the SP232 design is defined as the output of RS232 level: " 1 " be-5～-15V, " 0 " be+5～+ 15V, so through being output as the RS232 level of standard after the conversion of TTL RS 232 serial ports level translator.

Claims

1. serial ports level translator, it is characterized in that: comprise the D type data interface connector female of 9 pins, the D type data interface connector male of 9 pins, and be connected level transferring chip between the D type data interface connector male of the D type data interface connector female of 9 pins and 9 pins, the D type data interface connector female of described 9 pins is connected in the TTL serial ports of the last main frame of end, and the D type data interface connector male of 9 pins is connected in RS232 serial ports peripheral hardware.

2. serial ports level translator as claimed in claim 1 is characterized in that: described level transferring chip is SP232A.

3. serial ports level translator as claimed in claim 2, it is characterized in that: 2 pin of described level transferring chip SP232A are connected respectively to the D type data interface connector female of 9 pins and 1 pin of male by a capacitor C 3,6 pin are connected respectively to the D type data interface connector female of 9 pins and 5 pin of male by a capacitor C 4 respectively, 2 pin of the D type data interface connector female of 9 pins and 12 pin and 11 pin that 3 pin are connected respectively to level transferring chip SP232A, 2 pin of the D type data interface connector male of 9 pins and 13 pin and 14 pin that 3 pin are connected respectively to level transferring chip SP232A.