As a new generation of physical interface standards, TYPE-C is rapidly becoming a common element in the design of electronic engineers. Many engineers will have a misunderstanding at the beginning, that is, TYPE-C interface, be sure to use the CC logic chip, otherwise unable to communicate. This is actually a misunderstanding. USB - if the committee formulated type-C standard of intent, is to save social resources, but not a waste of social resources, imagine, if even a simple adapter, a U disk, a mouse, a ukey to type-C chip, will there be many people doubt is more than this in one fell swoop it? In order to allow engineers to have a simple criterion for this problem. The author uses three principles to help us to make this judgment:
First principle: if you want to provide more than 5V of the TYPE-C USB interface voltage, or more than 3A of the current, then it is necessary to achieve the TYPE-C interface chip PD USB protocol.
Second principle: if your device uses 5V voltage, and does not exceed 3A of the current. It depends on the power supply characteristics and data transmission characteristics of the device itself. If the device itself is only for external power supply, or only accept the other side of the power supply, and the role of the power supply and data transmission role as the default match (that is, the power supply side is HOST, the power side is Slave or device). So you don't need a TYPE-C chip.
Third principles: these two principles are used to determine whether the device requires TYPE-C chip, the other point is very concerned about whether the C-C transmission line needs to use the E-MARKER chip. This criterion is that the use of the process, the current will be more than 3A? If not more than, you can not need. A to C, B to C line, see whether there is a need for battery charging protocol implementation, if you want to achieve, is can use LDR6013, benefits, can realize charging, and can transmit data, avoid some don't conform to the battery charging protocol adapter to charge device.
Although the above three principles can help you save the chip, then how to save it? Also want to pay attention to the method:
First, with the power side and Device this end. The CC1 and CC2 are connected to the base of the C port, respectively, with two 5.1K pull down resistors. If you need to determine the direction of insertion, then use a comparator to compare the voltage on the two resistors (if there is a processor system, you can use ADC to determine), the comparison results that direction.
Second, power supply side or HOST this end (supply voltage is 5V). The and CC1 of the C port are respectively carried on the 10K and the CC2 by the up pull resistance of the two two. If you need to determine the direction of insertion, the use of a comparator, the two resistors on the voltage comparison (if there is a processor system, you can use ADC to determine), the comparison results that direction.
The above principles can help engineers and owners save a lot of money, ^_^, however, there must be someone to clap brick. Slaver side or SNK end people dare not say what? However, SRC or HOST, this end, there will be a lot of people jumping out, saying that this does not meet the TYPE-C standard, can not be easily released on the VBUS bus voltage. I want to say is, do not casually put out, such as a 9V, 10V, voltage of 15V, burn the other devices, but has been said above, is the premise, your working voltage is 5V, put a 5V voltage to the bus and may lead to problems, two 5V phase conflict. What happens after the 5V conflict? The actual power to do the people understand, high voltage, low voltage can be sealed. If you are unfortunate, the other side of the 5V output is PULL PUSH form, then, it is possible to trigger the situation of irrigation, but this situation, the design of the power supply itself should be dealt with the problem.
Therefore, if you want to have USB-IF certification, then, in addition to the kind of direct extension out of the adapter can not be pulled out of the USB common head output line, the other DFP applications are coupled with the TYPE-C USB chip. If you don't have to be certified, look at it. There is a sentence, called bad money drives out good money, the same can be used, the market will decide everything.
At present, I can see must type-C chip applications, including: notebook computers, mobile phones, tablet and mobile power to support high pressure fast charging adapter, you can refer to our joy, the Swiss LDR6013 series chip.
The above is only for reference, especially the statements of a school, the 5V bus on the part of the conflict. I dare not recommend the chip, it is because it is used, it is difficult to avoid conflict, especially the two TRY.SRC, two DRP devices are connected, and there is interference in the periphery of the case. In the Type-C era, all of the design, it is necessary to respond to the bus on the VBUS voltage conflict situation. Since all have to prevent conflict, then it can not be a natural.