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MAX17332 PushButton Wakeup issues

Category: Hardware
Product Number: MAX17332


We are dealing with strange behaviour of MAX17332, hope You will explain:

On a picture R93 and R97 replaced with low Vf diode, R158 replaced.

BT_ALRT goes to MCU.


PB_EN is set up (also in nvmemory).

We managed to send device in deepship/ship modes.

Button press does not wake up device. We waited 30s after it goes ship, pressed button up to 30s does not work. Played different scenario, never wakes up. But I see on voltmeter drop from 1v8 to 0 on ALRT/PIO pin.

But when we connect JTAG to mcu (1V8), so I2C lines also go up, and then I press button, MAX17332 wakes up and provides power to system. 

We want to use ship modes in this scenario: user charges device and put it in closet for (month), so when charged, device go to ship mode and wakes up with button press.

What do you mean in datasheet when you say "I2C collapse" does it mean 0v on both lines for (1000) ms? Does it mean, that there is voltage on I2C it wakes up? Or it wakes up on any communication on I2C? Or only on request specific to MAX17332?

I see it may come from a part of datasheet where it checks different wakeup inputs, and does not simply wake up by low level on PIO. 

  • Hi!

    There are a few things I'd like to check that may be contributing here. First, could you please do a register dump of both RAM (0x0XX) and NVM (0x1XX) registers just prior to sending the IC into Ship/Deepship? Confirming these settings would be very helpful for debugging purposes. Also, please ensure that you're waiting the full time required for the IC to enter ship mode following the FETs turning off. This setting can be checked in nDelayCfg.UVPTimer. It would also be helpful to have an oscilloscope screenshot of the CHG and ALRT pins when you're pressing the button.

    As for your questions on I2C wake-up, any edge on either of the I2C lines will wake the IC. This can be high-to-low or low-to-high, depending on the level that was present when the IC went into one of the low-power modes.

    Thank you and please let me know if you need any clarification.

  • Hi!

    Thanks for clarification on I2C wakeup!

    Our programmer is now on holiday, I will try to get dump, but maybe it is better to wait for him.

    nDelayCfg.UVPTimer we played, without it we would not be able to send IC in deepship in 10-20s.

    My main question, is there any other specific requirement to wakeup from the button, but to setup PBEN?

    Because it looks strange, when device wakes up from I2C, but not from pushbutton.

    Also we ordered eval board, so we can test it in pure conditions, maybe this issue comes from poor bga soldering.


  • Hi Stas, 

    If you're setting the PBEn bit in the nConfig register and seeing the ALRT pin drop from 1.8V down to GND when you push the button, then I would imagine that you're going through the procedure correctly. I'll wait for your programmer to return for the I2C dump, but in the meantime could you please send me a step-by-step procedure of how you're going through your test? Most importantly, I'm interested in any I2C interactions that you do and the amount of time that you wait before trying the wakeup process.