LM51772: Question about using ILIMCOMP (or CDC) as current monitoring

HI Cameron,

an easy way to get the configuration for ILIM and CDC is the quickstart calculator.

First of all you need for both functions a sense Resistor connected to ISNS pins.

For current limiting you need to have a resistor and a filter cap to AGND on the ILIMCOMP pin. (using ISET function)

If the limiter should be adjusted by the internal DAC this needs to be enable via I2C first.

For CDC to output the current monitor signal you just need a resistor to AGND on CDC pin.

VTH+ (BST_OV) is used to detect over charging of the BOOT voltage which is used to drive the high side MOSFETs

Best regards,

 Stefan

For setting IMON_LIMITER_EN bit to zero in Table 7-7. CFG4 Pin (R2D-CH4) Configuration Overview does the Current Limit need to be set to DISABLE 

Hi Cameron,

sorry, i struggle to understand your question above. Can you try to give some more details.

(The settings in the R2D interface are changing the configuration set by startup - this can be later overwritten by I2C.)

Best regards,

 Stefan

True- in hindsight my question makes zero sense :)

overall goal: to read an analog voltage to know current. We do not want chip current limiting feature. We do not use I2C with this LM51772

does this approach achieve our goal or is there a better way to do it? 

1) tie ILIM to VCC2

2) use a CFG4 resistor value which sets current limit to disable

3) read analog voltage output of CDC pin 

I’m finding verbiage in datasheet to be confusing . Thanks for the help to clear it up!