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re: Battery(charge current Max.580mA) use for TWL6032A2B4YFF

Kevin Huang67
Intellectual 410 points
Other Parts Discussed in Thread: TWL6032

We use the battery(charge current Max. 580mA) for the TWL6032A2B4YFF.
Can we change the R2 value from 20m ohm to ? m ohm, then we can limit the charge current(TWL6032 is 1.5A) to protect the battery ?
If it's OK. to has no side effect ? Thanks !

  • 0
    TI__Genius 17380 points

    Hi Kevin,

    Setting R2 to [1.5/0.58] * .02 ohm = 52 mohm sounds reasonable. The register map shows that using 15 mohm will set the current limit up by [20/15], so I would expect setting to 52 ohm should set the current limit down by [20/52].

    Alternatively, the VICHRG bits can be modified, but that would be after boot. 

  • 0 in reply to Kevin LaRosa
    Intellectual 410 points
    We use TI 6032 default hardware controlled charger with power path and has the below other questions.

    1. how to make PMIC detect USB charger port use TI6032 default Hardware based charger, by CHRG_DET_N=1?

    2 if we set PMIC Charger related register value like VICHRG,VOREG,VTERM, can PMIC hold the register value as long as the battery is plugged in?

    3. if AP is off, can TI6032 PMIC hardware controlled charger charge the battery with 100mA,since our battery can only support ~500mA max charge current?
  • 0 in reply to Kevin Huang67
    TI__Genius 17380 points
    Hi Kevin,

    1. The TWL6032 detects whether a charger is present by measuring VBUS voltage. Once plugged in, application processor should identify the type of charger and set CHRG_DET_N accordingly. See figure 4-22 in the datasheet (SWCS057H).
    2. Charger related values are stored as long as charger is plugged in and will be reset each time charger is unplugged to ensure that the wrong charger values are not used for subsequent charger plug ins. You can see which registers are in the Charger Domain in the register map (SWCU095B).
    3. The VBUS input current from USB is limited to 100 mA until CHRG_DET_N is set, so battery charge current would not be expected to exceed 500 mA. This is also in figure 4-22, the "USB Charging Port detected" is the CHRG_DET_N level.
  • 0 in reply to Kevin LaRosa
    Prodigy 30 points
    1. Can we use VBUS_DET interrupt of TWL6032 to change CHRG_DET_N from application processor or we must change it earlier than this interrupt?
  • 0 in reply to Francis Huang
    TI__Genius 17380 points
    Hi Francis,

    I expect VBUS_DET interrupt should give sufficient time.
  • 0 in reply to Kevin LaRosa
    Prodigy 30 points
    According to SWCS057H P75, "USB Charging Port Detected" decided CIN_LIMIT or E_CIN_LIMIT as VBUS input current limit by CHRG_DET_N.
    If I changed CHRG_DET_N after "USB Charging Port Detected", does PMIC change VBUS input current limit to CIN_LIMIT or E_CIN_LIMIT?
  • 0 in reply to Francis Huang
    TI__Genius 17380 points

    Hi Francis,

    My understanding is that E_CIN_LIMIT will be used until rising edge of CHRG_DET_N (for A2B4 OTP with DET_N_POL = '1'). After rising edge, CINLIMIT will be used until VBUS is removed.

  • 0 in reply to Kevin LaRosa
    Prodigy 220 points

    if we modified the CIN_LIMIT from 100mA to 600mA ,and change CHRG_DET_N from 0 to 1  after system has been booted,   when will the new  600mA input current limit  be applied?   do we need toggle CHRG_DET_N multiple time to trigger the rising edge to update the VBUS current limitation? are the limitation register only update under some condition?

  • 0 in reply to charlie zhou
    TI__Genius 17380 points
    Hi Charlie,

    Default CIN_LIMIT for this OTP is 1500 mA. If you change it to 100 mA or 600 mA, it will only be used after rising edge of CHRG_DET_N after charger is plugged in. Prior to CHRG_DET_N, the 100 mA E_CIN_LIMIT will be used. Unplugging and re-plugging charger will reset CHRG_DET_N latch and all registers in charger domain.
  • 0 in reply to Kevin LaRosa
    Prodigy 220 points
    CHRG_DET_N usage is vague for us, if we keep CHRG_DET_N=1, then I modify VICHRG,VOREG charger parameters, will the new value be used instantly or we need toogle the CHRG_DET_N in order to make the new value into effect?
  • 0 in reply to charlie zhou
    Prodigy 220 points

    another question about the CHRG_DET_N is :

        in the  TWL6032 datasheet it says it is Analog, and Nominal voltage is LDOUSB(3.3V), when I connect it to  GPIO(1.8V), what will happen? will the PMIC work correctly? or I need add a levelshifter from 1.8 to 3.3 in order form PMIC work properly

  • 0 in reply to charlie zhou
    TI__Genius 17380 points

    Hi Charlie,

    Toggling CHRG_DET_N has no effect after the first rising edge (For A2B4 OTP). Rising edge sets a latch to use CIN_LIMIT instead of E_CIN_LIMIT that can only be reset by removing charger.

    VIH for most of the digital signals appears to be expected voltage * 0.7 or 0.65, so I think level shifter is likely needed to ensure detection. You may want to test on the EVM () to confirm though.

  • 0 in reply to Kevin LaRosa
    Prodigy 220 points
    after CHRG_DET_N rising edge set a latch to use CIN_LIMIT, if we update CIN_LIMIT register value afterwards , will the new value take effect instantly ?
  • 0 in reply to charlie zhou
    TI__Genius 17380 points

    Hi Charlie,

    My understanding is that the new value will take effect immediately based on the documentation.

  • 0 in reply to Kevin LaRosa
    Prodigy 220 points

    after detail checking, we have found that E_CIN_LIMIT never took into effect even CHRG_DET_N is tie to 0, TLW6032 always use CIN_LIMIT, what is the reason for this?

    it is very dangerous for this case because default A2B4 CIN_LIMIT is 1500mA, this will crash the PC USB port instantly, we need boot the SOC then we can change the PMIC value. please advise how to make E_CIN_LMIT limit the VBUS current in the beginning.

  • 0 in reply to charlie zhou
    Prodigy 220 points
    we found ID pin voltage is 2.1V, after tie to gnd or 3.3V, E_CIN_LMIT will take effect
  • 0 in reply to charlie zhou
    TI__Genius 17380 points
    Hi Charlie,

    Thank you for the update. You are correct, with ID pin voltage of 2.1V it will indicate the presence of an accessory charger adapter (ACA). If using 16 uA current source for ACA detection, 2.1V corresponds to a 131 kohm RID value which is close to the RID_A value for an A type dedicated charger. Note that this explains why CHRG_DET_N was ignored (see page 103 Note section regarding ACA detection increasing VBUS input current limit).