Q:
Now I have use Th3122 to develop light module with K-BUS.
I have a question.
Do I can use LIN tranceiver (as TH8080) to replace K-BUS tranceiver(TH3122)?
LIN-BUS and K-BUS physical layer is or not compatible?
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A:
In principle is the physical Layer of K-Bus and LIN comparable from the voltage leveles as well as from the timing. The base for the LIN definition was the K-Bus.
The only difference you have to take into acount is the termination: With K-Bus you have always external pull ups in summary over the whole network of max 500Ohm and no reverse diode. With LIN you have always the slave termination integrated 30k/diode and at the LIN master a 1k with diode termination must be added external on this module.
Back to your question: If you want to change from K-Bus to LIN you can use the TH8082 as pure physical layer transceiver or you can also use our TH8062 which is a physical layer LIN transceiver plus a voltage regulator 5V/70mA similat to the TH3122.
To switch from K-Bus to LIN you have to secure that all external termination resistors from old K-Bus will be deleted and only at the LIN master module the 1k termination must be added.
The LIN protokoll is a complete other story, means this is complete differnt to K-Bus. You need on the protocoll side a new software driver for your MCU.
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Q:
I am thank your reply very much. I went to use TH8080 replace TH3122 as the K-BUS tranceiver. It is or not doable?
Physical layer Diffenrence between K bus and LIN bus, is or not infect message communication at K BUS.
I devolop light module with K BUS, and I use TH8080 as K bus tranceiver. In the future TH8080 and TH3122 is or not connect K bus as node at the same time, communication's reliability between them is acceptable?
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yes, you can use the TH8080 as physical layer. The TH3122 has additional integrated a voltage regulator. In case you use the TH8080 you must add this voltage regulator if you need it on you module as separate part or you use our new TH8062 which has already a 70mA voltage regulator and a LIN physical layer integrated.
The pure physical layer of K-Bus and LIN is comparable. The protocol is different!
The termination network for K-bus is always external and for LIN you have it for all slaves already integrated.
I don't understand you last paragraf! Therefore I have forward you email to our technical rep located in Hong Kong. Perhaps it is better to discuss with him directly. He will contact you asap.
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I am thank your reply very much. Excuse me, My english is not good.
Above my last paragraph is next note.
Now we are develop a body control module with K bus.
I want to use TH8080 or TH8062 for k bus tranceiver of my body control module. I want to know that TH8080 or TH8062 can is or not use for k bus tranceiver?
If my BCM with k bus use TH8080 and other ECU with k BUS use TH3122, then communication can is or not normally run between them which is connect a k bus?
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want to use TH8080 or TH8062 for k bus
tranceiver of my body control module.
I want to know that TH8080 or TH8062
can is or not use for k bus tranceiver?
This is possible. We have one customer which has such a solution is series production!
If my BCM with k bus use TH8080 and other
ECU with k BUS use TH3122, then communication
can is or not normally run between them which
is connect a k bus?
If you use the K-Bus protocoll for communication then it should be possible. Up to now we don't have such a case, but from the principle this should work.
All of our LIN transceiver are also compatible to K-Bus.
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I am trying to get the exact implementation of LIN protocol.
1. How to decide the initial NAD(node address) for a node?
2. What does Serial number indicate?
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1) The initial NAD is defined by the message catalog of the vehicle manufacturer or of the system supplier who defines the complete LIN network. The initial NAD must be known from the master to configure the slave.
2) The serial number is an unambiguous number of the slave. It is sometimes used for tracking purpose.
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Q:
LIN specification 2.0 speaks about wildcards, and it says that wildcards are useful in Node Configuration requests, if at all there is some unspecified information.
Is there any practical significance of this? Please try to explain it giving some suitable example.
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If we develop software for our ICs we always do this for a dedicated application. In this case we always have a clear definition of the used IDs. We haven't used the wildcard feature up to now.
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Q:
Has somebody the Eagle Library for the TH3122?
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A:
If you are using PCAD as PCB Tool.
The TH3122 has a standard SO16 wide body (300mil) package. You can easy create the TH3122 as library element with Eagle by using the SO16wb from the eagle standard package library.
look at http://www.cadsoft.de/ there you can find the Software. With this Software you can do Layouts for platinous.
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Q:
Question about the operation of the INH pin on this device: When the device powers up and is not connected to a CAN bus (i.e. sitting alone on a bench), what does the INH pin do? Does it intelligently allow a connected regulator to power up or does it remain inactive? The data sheet is a little unclear on this and I need to know how much extra design work is necessary to guarantee that the regulator connected to the INH pin is turned on when power is applied, whether or not the box is connected to a CAN bus.
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Section 3.7 and 3.8 of the datsheet explains the INH behavior. If you set one of the active MODES (M0 or M1 high), the regulator will be enabled. Otherwise, it will go to sleep.
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It was unclear to me what the state of the INH pin is when the device is powered up. If the device is powered up and the default state of the M0 and M1 pins at powerup are both low, what is the state of the INH pin? The state diagraom in section 3.8 of the data sheet defines an intermediate state called VBAT Standby, where the state of the INH pin is listed as "Vs", but the data sheet does not appear to define what Vs is. I'm assuming that it is some sort of high state, because the only other mention of Vs is in the High level output voltage spec in section 2.3. Could you clarify what "Vs" is?
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INH is high immediately after Power On for at least 100mS, no matter what the state of the Mode pins. After this time, the chip will either enter Sleep Mode (INH is floating) or one of the active modes.
Vs is the voltage at the VBAT pin.
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Q:
I use TH8056KDCA8(8PIN) in my device now,i want to exchange it to TH8056KDCA(14PIN) ,there's two question: 1\is it possible to exchange current part to TH8056KDCA ?
2\if it is available,how to deal with Pin9(INH)?connect to VBAT or isolate it?thanks
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From the functional point of view it is possible to exchange both versions without problems. The INH is a high side output for switching on/off an external voltage regulator. It switches between floating and VBAT level. Just keep this pin unconnected in your schematic.
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I am inquiring if there are any reasons I cannot use an TH8061 as a LIN master node, provided I apply the correct termination. Please advise.
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A:
The TH8061 LIN transceiver can be used for master and slave nodes. If you are using it for a LIN slave node you don't need any additional external termination, because of the integrated 30kOhm slave termination.
If you want to use it for a LIN master node a additional master termination to Vbat consisting of a diode and a serial resistor of 1kOhm is necessary.
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Q:
i am experimenting with a couple of LIN transceivers, TH8080 and TH8061. The TH8061 works all as expected but with the TH8080 i have trouble with the RX pin, it doesn't respond at all.
i have Tx and the LIN bus up and running but no sign of live from the Rx pin.
it is neither GND, 5V or 12V but seems to be floating.
I have tried to exchange the with another TH8080 (i have a few) but it is still the same result.
i have double checked my wiring and it all seems correct to me.
any ideas on what the problem could be?
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the TH8080 RxD pin is an open drain output. You have to connect an pull-up resistor of 2.7k to VCC (5V). This should solve your problem.
In the datasheet on page 16 you will find an application schematic, which explain it in detail.
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Q:
the reason i missed the pull-up is that i only looked at the TH8061 datasheet, and oddly enough they had forgotten the pull-up in that application circuit.
i'm gonna test the circuit with the pull-up later today but as you say, the pull-up should solve my problem, so i am optimistic =)
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There is a difference between TH8061 and TH8080. The the TH8061 has a push pull output and the TH8080 has an open drain output.
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i have tested my circuit with the pull up and it all works perfectly now, so thanx again.
the application circuit in the TH8061 datasheet (page 26) shows a slave-node with TH8061 and a master-node with a TH8080. anyway there is no pull-up in the TH8080 circuit. maybe someone should point that out to the author of the datasheet.
i have a general question about LIN. It seems like most LIN developers prefer the 9600 baudrate dispite the loss in response time. what is the main reason for that?
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A:
thanks for the input for the datasheet . It will be corrected in the next version.
The question about the 9600Baud transmission rate can't be answered in general. Some customers have concerns reagarding EMC if they go to 19600. They think that they will get EMC problems (because of single wire connection). We have tested this also for our products and there is no significant increasing of the Emission values. It keeps nearly the same level. Most German carmakers are already at 19600 e.g. BMW, DC and VW/Audi.
The used baudrate if it is not a closed system will be demanded from the vehicle manufacturer and then the developer has no choice
I think this is more a philosophical problem!
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A:
To switch off the internal pull up resistor you must enter the sleep mode (high->low transition on the EN pin). But in this mode LIN bus communication is not possible.
The TH8082 is designed according to the LIN specification Rev 1.3 and 2.0. In this specification the maximum of bus nodes is limited to 16. All pull up resistors and bus capacitors are designed for this maximum configuration.
Do you want to use our transceiver for a standard LIN network? If not, maybe it's better to use another transceiver from Melexis.
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it's a little bit difficult to use special bus tansceivers for more then one field bus system. In my opinion it will be better to use two different transceivers maybe the TH3122 for K-Bus and the TH8082 for LIN bus. So if you place the pattern of both transceivers to your PCB and select the monitor type at the assembly of your module you will get 100% compatible monitor modules for both field bus systems.
If you can't do this the TH3122 is closer to your specification than the TH8082. But keep in mind that the TH3122 is a K-Bus transceiver and not 100% compatible to the LIN bus. For instance it's possible that you get problems if you want to sent LIN messages with the TH3122. For a 'monitor only' application it should work.
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Q:
I want to use the TH8082 LIN-Bus Transceiver for a customer project.
I'm not sure if I can meet the customer requirements, because of the following problem:
From the datasheet I know that there is an internal 30kOhm pullup resistor on the Bus line.
In my application I need to switch this pullup on and off.
Can I do that using the Enable pin?
If yes, what means a switched off 30k pullup? Does it mean the Bus pin is grounded?
Another question:
What do I need the external 1k pullup in a master node for?
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As I already wrote, a key feature of my application is to switch the pullup on the bus on and off, but it must be possible to receive and transmit data even with the pullup switched off. That's possible if another node on the bus has its pullup switched on.
But if I use the Enable pin to switch the pullup off, I can't receive data any more, right? Which means this plan is not working...
How is it working anyway if you have for example 100 nodes with the TH8082 in a car and every node has a 30k pullup. You then need quite a big current to produce a dominant level on the bus...
And why does this external 1k master pullup change anything if every node has an internal one?
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thanks for the information.
Actually I want to use it as a K-Bus transceiver to build a K-Bus monitor. But probably later the application should also be usable as LIN-Bus monitor.
Do you have a chip which can handle both?
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Q:
I'm using the TH8100,but i can't find the documentation: "MLX LIN API specification".Can you tell me where can i get it?
By the way,it seems that the TH8100 can't be used as the LIN master.Can you recommend me the other similar controllers that can be used as the LIN master.Thanks!
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The API specification you will find since on our restricted access Softdist documentation system. To access this system contact a Melexis Sales Office. This is a system that requires client registration for accessing controlled documentation, one must be a qualified Melexis customer to be granted access.
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Q:
Question about the TH8100's PWM1,when i use the DCOM instruction to set the PWM1 to 100% duty cycle,i get a voltage of near 0v on the pin sw4.1/pwm1,but when set the other duty cycle,it works all right!why?
The following is my code:
#DEFINE PWMLSSMODE1 00h ;low side switch output(mode 1)
#DEFINE PWM1CrtlReg 05h
#DEFINE BaseAdr03 03h
;Initialization of PWM1
Mov a,#PWMLSSMODE1 ;low side siwtch mode
Mov b,#PWM1CrtlReg ;Control register address PWM1
Mov io:BaseAdr03,a ;Write data
dcom PWMDC100,01h ;set pwm1 to 100% duty cycle
who can tell me why? it's so boring a problem!!
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A:
sorry to say, but this is a small bug
in the datasheet of the TH810x.
The dcom PWMDC100 command is not availabe
for the TH810x. So please use the
sample code bellow to set 100% PWM.
to set PWM100%:
Mov a, #PWM1CrtlReg
Mov b, io:BaseAdr03[a]
Or b, #0100b
Mov io:BaseAdr03[a], b
to set any other duty cycle:
Mov a, #PWM1CrtlReg
Mov b, io:BaseAdr03[a]
And b, #1011b
Mov io:BaseAdr03[a], b
Dcom PWM1DC, 00h
Dmar #00h, Duty_Cycle
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Q:
Hi, recently, I have found several TH3092 IC in our university IC storage. I found out that the producer was probably Thesys gmbh, which was splitted to several companies. One of them was acquired by Melexix, I think. Do zou anybody have some idea, where to find some info/datasheet about this chip?
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A:
This part was not taken up by Melexis. I am sorry to inform you that we have no available information on it. Many Thesys ICs were acquired by Melexis but many were obsoleted or out of production prior to the merge. This seems to be one such case.
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