I am using this "SC18IS606" I2C-bus to SPI bridge chip in the circuit.

The datasheet is available under the link below.
https://www.nxp.com/docs/en/data-sheet/SC18IS606.pdf

I understand the address pins A0, A1, A2. I can have eight chips on one I2C bus with eight unique address set by address pins A0, A1, A2. I will connect these pins to VDD or GND accordingly.

I am not sure about how do I connect the following pins in the circuit.
SS0/GPIO0
SS1/GPIO1
SS2/GPIO2

I am not using these pins as GPIO.

Last question is what is the current consumption of this chip ? I am wondering about the power supply current.

 

I am not sure about how do I connect the following pins in the circuit.
SS0/GPIO0
SS1/GPIO1
SS2/GPIO2

I am not using these pins as GPIO.

Last question is what is the current consumption of this chip ? I am wondering about the power supply current.

But are you using them as slave select?

Where did you manage to find a microcontroller that has I2C but not SPI?

 

But are you using them as slave select?

I am having eight of these chips on I2C buss with different address selected through A0, A1, A2. I am not sure if I also need slave select. Kindly explain a bit what is the purpose of three slave select pins.

I know usually there is one chip select Cs pin or enable pin that are used to enable the device and to select the chip. But I don't understand why do we have three slave select pins and not one ? Kindly explain this a bit.

 

Where did you manage to find a microcontroller that has I2C but not SPI?

Sadly in our specific application, we can not have SPI interface to host for some reason. One of them is we have many chips on the board that are communicating to the host through I2C. There are also few chips having SPI. That is just one reason we need to use this bridge chip. But I agree that almost all the Microcontrollers having I2C also have SPI.

 

I am having eight of these chips on I2C buss with different address selected through A0, A1, A2. I am not sure if I also need slave select. Kindly explain a bit what is the purpose of three slave select pins.

I know usually there is one chip select Cs pin or enable pin that are used to enable the device and to select the chip. But I don't understand why do we have three slave select pins and not one ? Kindly explain this a bit.

The slave select pins are outputs that go to the CS pin on each SPI device, so that the SPI master can determine which peripheral IC it is talking to.

 

I think I get it.

The slave select pins ( SS0, SS1, SS2) are three output pins that need to be connected to the CS pin on each SPI device. Does it means that we can connect three slave SPI chips with one "SC18IS606" ?

The SPI master will determine or select which peripheral IC to talk with.

 

I think I get it.

The slave select pins ( SS0, SS1, SS2) are three output pins that need to be connected to the CS pin on each SPI device. Does it means that we can connect three slave SPI chips with one "SC18IS606" ?

The SPI master will determine or select which peripheral IC to talk with.

Correct.

 

I get the static current from Table 13.

But how can I add or get the current from Table 12 ?

I have highlighted the three rows in Table 12 in attachment.

I am not using GPIO0, GPIO1, and GPIO2.

Only one SPI slave is connected to SC18IS606.

The SS0 pin of the SC18IS606 is connected to CS of the slave SPI.
The MISO pin of the SC18IS606 is connected to SDO of the slave SPI.
The MOSI pin of the SC18IS606 is connected to SDI of the slave SPI.
The SPICLK pin of the SC18IS606 is connected to SCLK of the slave SPI.

The address pins A0, A1, A2 of the the SC18IS606 are connected either to VDD and or to GND.
The SDA and SCL pins pins of the the SC18IS606 are connected to host MCU.

How do I calculate the power supply current ?

 

I get the static current from Table 13.

But how can I add or get the current from Table 12 ?

I have highlighted the three rows in Table 12 in attachment.
.

How do I calculate the power supply current ?

Not from the maximum output capabilities!
How about “ operating supply current” in section 10?
maximum = 4mA

 

Not from the maximum output capabilities!
How about “ operating supply current” in section 10?
maximum = 4mA

Oh yes. The Table 12 presents the maximum limits.

 

If I use 5 mA current for one SC18IS606. Would that be ok to count 5 mA as power supply current. ?
And if I have eight chips connected on the same I2C then the total current which I am counting is 5 mA x 8 = 40 mA.

But then I am thinking, only one chip will be active or working at a time, and not all.

Let's say all of them are working.

How about if I take 40 mA as power supply current for eight SC18IS606 ?

 

If I use 5 mA current for one SC18IS606. Would that be ok to count 5 mA as power supply current. ?
And if I have eight chips connected on the same I2C then the total current which I am counting is 5 mA x 8 = 40 mA.

But then I am thinking, only one chip will be active or working at a time, and not all.

Let's say all of them are working.

How about if I take 40 mA as power supply current for eight SC18IS606 ?

Seems like a reasonably safe assumption.
You could assume that some are “idle” but that only reduces the current to 3.4mA, and the difference is less that the limits of error, so you might as well forget about it.
If any of them are powered down (you’ll have to look how you make them power down) then it’s only 75uA, so if your current budget is small, the powering them down would be helpful.