TMS570LC4357: ADC microcontroller TMS570LS4357

I need  just  information  about  what input  will come to  both IC  , will sensor  can we  connect  directly  to   IC  LTC1992CMS8#PB   or  we  can any changes, from pressure sensor 

thank you sir 

Dear  sir   update  on   doubt what i asked 

what  sir  no reply 

Hi Jeev,

Can you please share your connectivity diagram for better understanding of your connectivity.

--

Thanks & regards,
Jagadish.

CIRCUIT.docx      THIS  IC  WHAT WE ARE USING SIR ,  FROM  PRESSURE SENSOR GETTING  OUTPUT  IS CONVERT  INTO VOLTAGE  AND GIVEN TO THIS IC  . 

THIS  TWO IC  FROM TEXT INSTRUMENT ONLY  SIR , ACCORDING TO MY ASSUMPTION AFTER READING  DATA SHEETS OF IC  , FIRST  IC  WILL TAKE  INPUT 5V  AND GIVEN 2.5V  AND  LATER SECOND IC TAKE 250MILLI VOLT  AND  GIVEN OUTPUT AS -/+ 2V . IS THIS CORRECT SIR

SIR   ANY UPDATE

Hi Jeev,

I will study the datasheets of LTC1922 and AMC1200, then provide comments later today.

dear  even i studied data sheet  from IC  LTC1922   we supply vs as 3.3v ,   what output it will provide  , in  data sheet  5v to 0v  , in this case  input for second IC AMC1200  is taking  250mv , how sir ,  in our circuit  we have connect  one resistor  100 ohms and  parallel  capacitor  100pf , between two IC ,  that  only  u clear sir enough for me please sir 

Hi Jeev,

TMS570LC43x has two built-in single-ended input ADC modules. The output of AMC1200 is isolated differential-output. Please add a differential to single-ended amplifier between AMC1200 and TMS570LC43x device.

dear sir

instead of adding  Differential to signal-ended  amplifier   between  AMC1200   and  controller , shall i remove IC  LTC1922  which  signal -ended  to   differential amplifier  this is fine sir

we  have  input  PCB  card   it as 96 pin connector  where  input is given 24v ,  from sensor  whatever output come we need to convert  into 24 volt and give to  connector , then only this IC connection circuit . this is assumption , it correct sir 

thank you

what  are  sir no reply

ok sir , i will take care, while coding if i have any  doubt i will ask u sir .

thank you

Hi Jeev,

The LTC1992 and AMC1200 are used to amplify the analog input signal and generate differential signals for MCU. You can configure LRC1992 to output a single-ended signal for MCU.

Dear  sir   from  pressure  value to current value output formula is  pressure  =(( I-Imin)/(Imax-Imin))(Pmax-Pmin)+Pmin.  maximum  pressure  is 10 Bar iam taking is this fine sir 

Hi Jeev,

You said the output of pressure sensor is current. The ADC measures voltage only. You need to convert current to voltage first. You can use the single ended of LTC.

analog.pdf      

Dear  sir  my analog  circuit  iam using  pressure sensor  which  provide  output as  4mA  to  20mA  ,  sensor output  is  connected  to  this  circuit  for one doubt sir  if  i supply that  how  this circuit will work  and  analog  signal (voltage ) flow  from starting of circuit to end  of this  circuit AN4 & AN5  is  directly  connected   to  microcontroller ,  for getting  confuse  , AC  is  supply from sensor through  circuit  from microcontroller  Analog channel   pin  in  microcontroller . please  response soon sir , i will wait for u r   reply.

thank you

jeeva

kindly  response  fast  because  of  that   project  is  struct   please help us  to   move  front 

what  sir no reply 

If R2=150ohms, the voltage range cross the resistor R2 is 150*4=600mV and 150*20mA=3V.  The LTC1992 can be configured to be a voltage-follower (OP amplifier with unity gain). The LTC1992 can be used for single-ended input too.

Does your pressure sensor have differential output or single-ended output?. 

Single-ended output , Its   produce  analog signal like current form  4mA to  20 mA  

what  sir  no  reply , is  they  any wrong 

Dear  sir  iam asking  if supply  4mA  to  20mA   output of  pressure sensor   to  circuit  which i  have  sent ,  along  current output  some  short of  voltage   will  flow   to   given  circuit   what  will   be  end  of  circuit  output  , what may  come  in AN4  and   AN5   Analog pin  , that  enough sir.

thank  you 

Hi Jeev,

I don't understand your question very well. The output of your pressure sensor is current rather than voltage, but the ADC only samples voltage. You have to convert current to voltage using either a shunt resistor (my diagram in my last message) or a transimpedance OP amplifier (article below). 

https://www.digikey.com/en/articles/how-to-design-stable-transimpedance-amplifiers-automotive-medical-systems

If the pressure sensor outputs a single-ended, why do you use a differential circuit to amplify this single-ended current signal? How do you convert current to voltage for MCU?