dear friends ,
currently am working on lighting control module in that i have used above high side switch in that there is pin called (CSNS) on that pin we can read ADC values of load i.e how much load(voltage) currently on that pin (HS0,HS1,HS2,HS3), by using this we can know whether load is ON or OFF or other data, now my query is,
1) if we generate PWM on this above pins using internal clock of this high side switch or by using microcontroller how we will get stable ADC values on CSNS as load will be on and off continiously because of PWM, am having this problem and stuck over here, i have done all the connection(interfacing) using application diagram from the datasheet
currently am using MC9S12G48 freescale microcontroller for this purpose
2) my second query is i have set the bus frequeny of 25MHZ for my microcontroller(MC9S12G48) and for SPI communication with MC10XS3425 this device i have set baud rate of 6MHZ which is higher ,can i use 12 MHZ baud rate for communication purpose because in microcontroller datasheet they have mentioned that for higher baud rates refer electrical characterstics is there is any problem in using higher baud rates as i am new in this communication protocall..
Hi,
1) As described in the datasheet, the CSNS output delivers current only during the ON time of the output switch, so there is no way to get a current proportional to the selected output current throughout the entire PWM cycle, including the OFF phase, unfortunately.
2) SPI max is defined up to 8MHz in the MC10XS3425 data sheet. All possible SPI bit rates for 25MHz BUSCLK are available in the table Table 21-6. Example SPI Baud Rate Selection (25 MHz Bus Clock). Max possible bit rate compatible with MC10XS3425, I found, is 6.25MHz.
Best regards,
Ladislav