MAX77962
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The MAX77962 is a high-performance wide-input 3.2A buck-boost charger with a Smart Power Selectorâ„¢ and operates as a reverse buck without an additional...
MAX77962 on Analog.com
Hi,
I have problem with my MAX77962 to set current and voltage values on different registers, such as 0x18, 0x1A and 0x1E registers. I followed the same circuit as the in datasheet to control settings over I2C. So, I pulled-up the VSET, ISET, INLIM and ITO pins to PVL with a 1K resistor. The entire circuit works fine. That means it charges my 2Cell battery when input current, VBUS, is set at 500mA (which is the default). I am trying to increase this current together with charging current using both I2C commands and pulling-down with a resistor. But none of them will change the current. As for I2C, it seems I have to set the FSHIP_MODE = 0 (which is already 0) and COMM_MODE = 1. For the later one, when I read the register value it's 0x05. But I wrote 0x85 to enable I2C mode. The value is still 0x05.
I would like to know if I have missed anything in my code and settings that none of my writing to I2C works. By the way, I only see writing to DISBIS bit effective as it disable/enable the charge cycle.
Thanks Amir
Hi Amir, your question actually helped me find the solution! By default, most registers on the MAX77962 are locked from writing. This is due to the CHG_CNFG_06 register that contains the field CHGPROT in bits 2 and 3 that locks "Protected registers from writes". Writing 0x0C (0b1100) to the CHG_CNFG_06 register (0x1C) will unlock those registers for writing!
Thanks,
Mason
