MP2672A Charging Current 30% Low

[igal.brodetsky]

I’m using the MP2672A in the host control mode with RISET at 6.04K. When charging, the charging current I’m seeing is about 30% below what I expect.

I’m measuring the current right at the battery. I used a few ICC settings. Here is what I’m getting:

ICC	Current (A)	Expected (A)	%Drop
1111	1.35	2	32.5%
0011	0.535	0.8	33.1%
1100	1.2	1.7	29.4%

Here is what I’m reading at the I2C bus when ICC is 0011:

At other ICC values, the numbers are the same, except for REG[1], which reads the ICC.

I tried this on two different boards with exactly the same results. The battery voltage when this occurs is about 7.5V. This is the battery voltage, not the charging voltage.

My schematic is like this:

Any ideas why this is?

[Ryan.FAE]

Hello @igal.brodetsky ,

Thank you for bringing this matter to our attention. To help us clarify your issue, are you seeing this drop off only when the battery reaches 7.5V? Does the charging current ever reach the expected Icc? Furthermore, does the battery voltage continue to increase to your desired Vbatt?

From your register settings in the example screenshot, register 1 show that the IC is reading an output current of 0.8A. These register readings can be found on page 29 of the datasheet for your reference.