1. Channel 1-12 are used identically.
2. Channel 13 is used but its sibling pair Channel 14 is left open always
3. Channel 15 and 16 is also left open always
the use of both highside and lowside switch in one circuit makes it difficult.
(i wonder what the idea behind that is...)
But then open load detection can not work in combination with the low side switches, because they create the "open load" condition even if the solenoid is OK.
For open load connection, the hig side switch should be "open"while the low side switch should be "closed"
--> You can´t detect which single channel is "open load", the status signal is always a combination of two channels.
--> if only one channel is used, then you should connect a dummy load instead of the unconnected solenoid, to get a "good" status signal. Try 750R, 2W
--> according truth table the "overcurrent" state should be recognized
Maybe the designer does not know ... but there must be a person who connects the solenoids to the PCB. He knows where to connect a solenoid, and if there should be no solenoid he should connect a 750R instead.Pain at designer side is no one knows which channel will left open, we needed to detect it in software.
As we have tested with open load (Solenoid is disconnected, Lower FET is ON, Higher BTS Channel is given Input) in BTS716G ignoring the state of error signal, BTS716G getting high temperature, so if you would explain overcurrent detection it would be a pain release. Thanks in advance.
Maybe the designer does not know ... but there must be a person who connects the solenoids to the PCB. He knows where to connect a solenoid, and if there should be no solenoid he should connect a 750R instead.
Is this a possible solution?
(connect a 10kOhms pullup on each BTS716G output. This is urgent for open load test.)
To test for high temperature:
* place both channel inputs "H"
* if status shows "low", then an overtemperature occured.
Yes. This is to pull the output weakly to 24V. When no load connected, then there will be voltage above 4.0V (highest threshold level of BTS716), with load it will be below 1.7V (lowes threshold level).Are you suggesting at pin 13, 14, 17 and 18 here:
First of all sorry that I have forgot to mention, for error detection I can not manipulate the Inputs / PWM signal to the pin no 3,5,7 and 9. They are calculated from a specific routine, so I can
1. only wait for both signal to go for "H" and at that moment I can measure status signal for over temperature,
2. if over temperature is not the condition, I will wait for open load conditions one by one as you suggested.
Check datasheet on the delay times from "input to status feedback". Your software needs to wait, before reading valod status information.only wait for both signal to go for "H" and at that moment I can measure status signal
My procedure of post#4 should give always valid status information.But the problem with this is when only one of the channel is in use, the other channel (should be) kept open via lower FETs and input for the respective channel will always be Low.
So what will be value of status signal when the channel which is actove will go for temperature / open load? Will you please help me with that?
Only in "no overtemperature condition" you can check on "no load". (during "overtemperature" both channels show wrong "no load")
For independently detecting "no load" you have to switch one channel ON while the other is OFF. Look at my post #4.
Therfore your truth table is wrong in this. It always shows both channel inputs "1"
If the knowledge about "over temperauture" and "open load" is important, then you need to talk to your software engineer to include the function.
Yes, max. 2.4mA. Without current i can't imagine how to detect a load...For Pulling Up 10k at Higher side FETs, Doesn't it provide few miliamps to solenoids when Input PWM is 0%?
Because datasheet says that at least one channel input has to be high to test on overtemperature.I am not getting your point here, in my examination, even if when one of the channel is short circuited and other is open circuited, it gives the status "Active (Low)". Is it like to get Over Temperature error channel must be ON first? Is it why I am getting this?
Please work through the datasheet carefully.I am not getting this point, sorry for my slow learning, will you please elaborate this? Also consider newer truth table while helping me out. Thanks for that.
Then the check on overtemperture in my procedure is redundant. Just do the two checks on "open load"1. No only the indication of fault condition for particular channel is required. No need to differentiate Open load or over temperature. But as you said for over temperature, we can not differentiate which channel is faulty
It's not that easy. A simple combinatorial logic won't work. You need additional delay logic to capture the status signal and timed logic to validate your results.2. My requirement is to design a logic (Software) which takes PWM Input1 , PWM Input 2 and Error Status signal as Input and provide Two Fault 1 and Fault 2 output. I hope I am not confusing here.
//Here ReadingValue is a copy of last reading
//of pin no 3,5 and 4
//0th bit is INPWM 1
//1st bit is INPWM 2
//2nd bit is Status1/2
(0x00 : Status1/2 = 0, INPWM2 = 0, INPWM1 = 0)
(0x04 : Status1/2 = 1, INPWM2 = 0, INPWM1 = 0)
(0x05 : Status1/2 = 1, INPWM2 = 0, INPWM1 = 1)
(0x07 : Status1/2 = 1, INPWM2 = 1, INPWM1 = 1)
//Possible error state means
//0 - No Error
//1 - Open Load Channel 1
//2 - Open Load Channel 2
//3 - Open Load Channel 2, Open Load Channel 1
//4 - Open Load Channel 2
//6 - Over Temprature Channel 1,Open Load Channel 2
//8 - Over Temprature Channel 2
//9 - Over Temprature Channel 2, Open Load Channel 1
//12 - Over Temprature Channel 2, Over Temprature Channel 1
Reading Value = 0 -->>Possible Error State = {1,2,3,6,9}
Reading Value = 1 -->>Possible Error State = {2,3,4,6,12}
Reading Value = 2 -->>Possible Error State = {1,3,8,9,12}
Reading Value = 3 -->>Possible Error State = {4,6,8,9,12}
Reading Value = 4 -->>Possible Error State = {0,4,8,12}
Reading Value = 5 -->>Possible Error State = {0,1,8,9}
Reading Value = 6 -->>Possible Error State = {0,2,4,6}
Reading Value = 7 -->>Possible Error State = {0,1,2,3}
Reading Value = 4 --> Possible state of error : {0,4,8,12}
Reading Value = 5 --> Common state of error : {0,8}
Reading Value = 0 --> Common state of error : {8}
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