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.
This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
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.
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.
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
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.
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.
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.