Ltc2439-1 in SPI communication data output is high first out or low first out?

Looking at the timing diagram of Figure 3a, I think there could be something wrong with your communication with the ADC. The first two bits should always be zeros. Can you provide an oscilloscope photo showing CSL, SCK, SDI and SDO? A schematic of your circuit would also be helpful.

• Read channel 0 data, single-end input, single chip sends 0XB0, right

I do not understand your question. What are the charging current and cut-off voltage you are referring to? This sounds more like a switching regulator than an ADC.

• Sorry, I misremembered! It's the BQ24650 chip.

Ltc2439-1 chip, internal shock MCU communicate with other SPI, MCU send channel command after waiting for how long to start reading?

After MCU sends the read command, how long will it take for ltc2439-1 to be converted and the MCU to read the data?

See Table4 for specification, conversion time 147ms.

At present, I send the channel command with a delay of 200ms, then send the read command with a delay of 200ms, then read the data.

Why is this chip communicating so slowly?The display speed of the touch screen is too slow to refresh.

It would be nice to have an ltc2439-1 communicator example available!

The problem now is that the ltc2439-1 data read time is too slow.

My reading order is: send channel command -> delay 200ms-> send read command -> delay 200ms-> receive data.

The data received should now be correct.That's how long it takes to read?It would be even better to have program examples!Thank you very much!

As I mentioned previously, this is a relatively old device. There are no code examples available. Newer devices are available with faster conversion times and code examples. The LTC2448 and LTC2449 are 16 channel ADCs that can sample up to 8ksps and both have code examples available.

As can be seen from the table, the conversion time of LTC2488 is 145ms, which is also very slow. My design is used by LTC2488 and LTC6811 at the same time. It would be nice if the communication speed of LTC2488 is the same as that of LTC6811, thank you!

I suggested the LTC2448 not the LTC2488. The LTC2448 can have a conversion time as fast as 1.13ms. 

I wrote it wrong, it is 2448. Could you please tell me whether the LTC2449 contains input filter, the difference between 2449 and 2448?Thank you very much!

Both the LTC2448 and LTC2449 contain a decimating FIR filter. The LTC2449 has access to the MUXOUT/ADCIN points so that an external buffer can be used.

Look at datasheet, LTC2449 is half as noisy as LTC2448, right?So I want to choose LTC2449, ok?

Thank you very much for your reply!

Look at datasheet, LTC2449 is half as noisy as LTC2448, right?So I want to choose LTC2449, ok?

Thank you very much for your reply!