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TPS2543/46 Max. charging current with new iPAD(2.4A)...

Other Parts Discussed in Thread: TPS2543, TPS2546EVM-064, TPS2546, TPS2511, TPS25200, TPS2514A, TPS2561A, TPD2E001

Dears,

As I know, TPS2543/46 cannot support new iPAD 2.4A charging mode.

However, what is the Max. charging current at this situation?

Is it able to up to 2A for new iPAD charging even it is not in new divider mode?

Any comments is welcome.

  • Peter,

    TPS2543/6 support iPad 2.1A charging mode, it can do up to 2A charging. The DC voltage has big impact on charging current, usually needs to set around 5.15V. Also whether iPad's display is on or not also has quick impact.

     2.1A ID and 2.4A ID are compatible with iPads:

    Older iPad can do 2A with 2.4A ID.

    New iPads like iPad4/Air can do 2A with 2.1A ID, 2.35A with 2.4A ID.

     

  • Hello Vincent,
    One of our customer wants to charge to iPad Air with 2.1A charging mode too. Now they are trying to charge iPad Air using TPS2546EVM-064 but the charge mode is standard mode (0.5A). The charge mode can not be changed to DCP mode (Divider Mode 2 - 2.1A). CTL1/2/3/ILIM_SEL setting are 0/1/1/1. They are using iPad Air genuine charging cable and the DC power supply current capability is more than 3A.
    Could you please give me your advice which point the customer should check or change to change TPS2546 charging mode to 2.1A mode?
  • Nakai-San,

    Under DCP, it's equal to adapter, charge only, no data communication required.

    Under SDP, to support iPad fast charging, it requires a processor from Apple, called iPad. It can program charging current of iPad 2.1A. Without it, under SDP, it can't charge iPad directly.

  • Sorry for typo, the Apple processor is called "iAP"
  • Hello Vincent,

    Thank you for your reply.

    According to your reply to Peter, TPS2543/6 support iPad 2.1A charging mode, it can do up to 2A charging.
    Do you mean that some communications are needed between iPad Air and controller via TPS2546 D+/D- port?
    Can we not change iPad Air charging mode from SDP mode to DCP mode without some communications
    between controller and iPad Air?

    Do you know any TI USB device which can charge iPad Air with DCP mode without any controller?

    Our customer needs such device strongly.

    Thank you and best regards,
    Kazuya Nakai.
  • Nakai-San,

    Under DCP, no communication needed, customer can use tps2546 DCP mode or device like tps2511/4.
    Under SDP, to support fast charge to iPad, data communication is required and it should be done by Apple processor.
  • Hi Vincent,

    Thank you for your reply.

    Could you tell me which USB charger device would be recommend which can support DCP mode to charge iPad Air with the lower price?

    Best regards,
  • Nakai-San,

    Tps2514A supports 2.4A charging. It has no power switch, if customer needs to add one, they can choose tps25200 together with tps2514A.

    If customer needs dual Chanel, they can use tos2513A+tps2561A

  • Vincent,

    Our customer needs a power switch for single port.
    Also the customer needs USB charging device which can support DCP mode to charge iPad Air with 2.1A (Divider 2 mode) charge current.
    In the case, is TPS2543 the best device for low cost?

    Best regards,
  • Nakai-san,

    In this case, best choice is TPS2511.

  • Vincent,

    Thank you for your reply.

    If our customer uses TPS2511, does the customer not need to send any command to iPad Air to enter 2.1A charging mode(Divider 2
    mode)?

    best regards,
    Kazuya Nakai.
  • Nakai-san, No need, TPS2511 can handle the charging to iPad.
  • Vincent,

    I understood.

    Thank you very much for your help.

    Best regards,
    Kazuya Nakai.
  • Vincent,

    Thank you for your reply. I see. I will recommend TPS2511 when
    the customer request us to discount TPS2546 price strongly.
    At this moment, TPS2546EVM is working well to charge iPad Air (Model A1567) with 2.1A charge current mode. The cause was a miss some jumpper setting of CTL1/2/3/ILIM_SEL pin on EVM.
    They thought level "1" means shorting between CTL1/2/3/ILIM_SEL and GND and "0" means
    opening between CTL1/2/3/ILIM_SEL and GND.

    The customer will use TPS2546 for their product if the following their questions are cleared.

    So could you please give me your answers?

    Questions:
    1. When TPS2546 OUT(pin# 12) is connected to iPad Air, the output voltage becomes almost 0V a moment after about 1~2 second passed from the iPad Air connection.
    Os this behaiver correct?
    2. When TPS2546 detemine the charging mode(DCP/CDP/SDP etc) after connection to iPad Air?
    3. The determined charging mode is not change as long as iPad is connected?
    4. When Iphone5 or 6 is connected to USB port which has 2.3Amp capavility directly not via TPS2546 EVM, then the customer observed the charging current was about 900mA. Is TPS2546 not need for 900mA charging mode for iPhone?
    5. The customer observed that the charging current is 2.1A when TPS2546 EVM is connected to iPad Air genuine adapter(5.1V,2.1A).
    Also they observed that the charging current is 1.9A when TPS2546 EVM is connected to 5.0V 3A power supply. And they 1.7A is observed when TPS2546 EVM is connected to 4.8V 3.0A power supply.
    Is charging current changed depend on TPS2546 IN (pin# 1) voltage?
    Is there any relation graph between IN voltage and DCP mode charge current?
    6. Could youplease what is difference points between CTL1/2/3/ILIM_SEL
    setting "0111" (Jumper setting: short-open-open-open) and "0110"
    (short-open-open-short)? The both are DCP auto mode.
    7. When the customer connected TPS2546 EVM to the iPad (A1567) many times, most of the result were DCP mode (about 1.8A) but other is 900mA mode. What do you think what the cause is.
    If you have any idea, could you please tell me to solve the customer
    problem

    Thank you and best regards,
    Kazuya Nakai.
  • Nakai-san,

    Here are the answers.

    1. When TPS2546 OUT(pin# 12) is connected to iPad Air, the output voltage becomes almost 0V a moment after about 1~2 second passed from the iPad Air connection.
    Os this behaiver correct?

    [Vincent]: yes, it's correct. TPS2546 is doing mode changes from divider 1 into divider 2, in between a Vbus discharge will happen with timer 2 seconds.


    2. When TPS2546 detemine the charging mode(DCP/CDP/SDP etc) after connection to iPad Air?

    [Vincent]: No, it's system decision, TPS2546's mode is set by GPIO of  CTL1/2/3, ILIM_SEL.


    3. The determined charging mode is not change as long as iPad is connected?

    [Vincent]: In this case, customer is using DCP/Auto, it default divier 1 mode, when iPad connected, TPS2546 decides to switch into divider 2.


    4. When Iphone5 or 6 is connected to USB port which has 2.3Amp capavility directly not via TPS2546 EVM, then the customer observed the charging current was about 900mA. Is TPS2546 not need for 900mA charging mode for iPhone?

    [Vincent]: Without TPS2546, what's the type of USB port on customer's system? Is it DCP/BC1.2 shorted (DP/DM shorted together with 200ohm resistor)? If so, iPhone can support it and charge 900mA.

    BTW, iPhone 6 plus can charge up to 1.8A with TPS2546. 900mA is not max for iPhone.


    5. The customer observed that the charging current is 2.1A when TPS2546 EVM is connected to iPad Air genuine adapter(5.1V,2.1A).
    Also they observed that the charging current is 1.9A when TPS2546 EVM is connected to 5.0V 3A power supply. And they 1.7A is observed when TPS2546 EVM is connected to 4.8V 3.0A power supply.
    Is charging current changed depend on TPS2546 IN (pin# 1) voltage?

    [Vincent]: Yes, correct. The Vbus voltage and Vdroop on Vbus will impact charging current to iPad. Lower voltage, lower charging current.
    Is there any relation graph between IN voltage and DCP mode charge current?

    [Vincent]: It's iPad behavior. It has minimum voltage it can accept on iPad input. For iPad Air, it's about 4.4xV. Once it reaches this lowest voltage, it will keep the charging current and won't be able to pull more. The relationsip can be roughly caculated as the following formula:

    Vbus (USB Connector) - 160mohm (lighting cable resistance)*charging current = 4.4xV (lowest voltage iPad Air can accept at connector side).


    6. Could youplease what is difference points between CTL1/2/3/ILIM_SEL
    setting "0111" (Jumper setting: short-open-open-open) and "0110"
    (short-open-open-short)? The both are DCP auto mode.

    0111 is DCP/Auto with load detection. /Status pin is active, detection threshold is set by ILIM_LO resistor setting.

    0110 is DCP/auto without load detection, /status pin is disabled.


    7. When the customer connected TPS2546 EVM to the iPad (A1567) many times, most of the result were DCP mode (about 1.8A) but other is 900mA mode. What do you think what the cause is.
    If you have any idea, could you please tell me to solve the customer

    [Vincent]: TPS2546's DCP/Auto will switch mode accordingly, the mode changes and reset to initial mode takes time, the deglitch timer is needed to avoid noise. If fast flug iPad many times very quickly, TPS2546 may not be able to cycle back.

  • Vincent,

    Thank you for your prompt reply.

    About #2 question.
    Do you know when iPad finish to determine the charging mode after connection to TPS2546?

    About #3 question.
    Do you know iPad charging mode is not changed during the charging from the determined charging mode?

    About #4 question.
    I will check whether the customer USB port DP/DM have 200ohm resistor or not.

    About #7 question.
    Do you know how long interval time between iPad dis-connecting and next connecting is needed?

    Best regard,
    Kazuya Nakai.
  • Nakai-san,

    About #2 question.
    Do you know when iPad finish to determine the charging mode after connection to TPS2546?

    <> Default divider 1, if charging current exceed 750mA (max up to 1A), maintain 2s, TPS2546 has one time 2s discharge, then switch to divider 2, then start charging with around 2.1A. But if the ipad's battery fully charged, plug in TPS2546, charging current lower then 750mA, will stay at divider 1.

    About #3 question.
    Do you know iPad charging mode is not changed during the charging from the determined charging mode?

    <> As explanation above, if switch to iPad, when fully charged and charging current lower than 650mA, TPS2546 will switch to default divider 1 and stay.

    About #4 question.
    I will check whether the customer USB port DP/DM have 200ohm resistor or not.

    About #7 question.
    Do you know how long interval time between iPad dis-connecting and next connecting is needed?

    <> The last gen TPS2543, diver 1 to divider 2 discharge time is around 310ms, but customer found several iPhones in Taiwan can't charge, so in TPS2546 we chagne the timer from 310ms to 2s, so far no customer feedback fail charging for TPS2546 with apple device.

  • Vincent,
    Our customer will use TPS2543 if the following questions are cleared.
    Could you please answer?

    1. The customer is charging iPad Air using TPS2546 EVM. But the customer wants to use TPS2543
    because the device is cheaper than TPS2546 a little. TPS2543 doesn't support 1.2V/1.2V mode in DCP_Auto mode. TPS2546 supports 1.2V/1.2V mode. If 1.2V/1.2V mode is not supported,
    is it no problem to charge iPad Air with 2.1A high speed charging?
    Can TPS2543 charge iPad with 2.1A high speed charging when TPS2543?

    2. According to TPS2546 EVM schematic, 150uF tantalnium capacitor is needed to attached between
    OUT and GND of TPS2543. Can we use 150uF ceramic capacitor instead of tantalnium one?

    3. According to TPS2546 EVM schematic, ESD protection part and common mode choke coil are
    used on D+/D- signal line. Are these parts mandatory?

    Your reply would be appreciated.

    Best regards,
  • Hi Vincent,

    Could you please reply to my questions?

    Your reply would be appreciated.
  • Nakai-san,

    Sorry for late replay. Here are the answers.

    1. Yes, TPS2543 DCP can support 2.1A charging to iPad. If customer doesn't need 1.2V/1.2V in DCP/Auto, they can choose TPS2543.

    2. Yes, they can use caramic capacitor in output.TPS2543/6 has strong current limit function, its function doesn't require capacitor, but based on UL certification requirement, we usually put 150uF cap on output.  

    3. Yes, IEC ESD protection part and common choke are needed on D+/D-. Relatively D+/D- is weak point in system, TPS2543/6 has its ESD protection block for HBM, CDM, but it' s not for system level protection like IEC ESD test Contact 8KV, Air discharge 15KV. We do recommend customer to have good system ESD protection design on board. On TPS2546 EVM, with TPD2E001 and common choke, the EVM can pass system ESD test.