TPS25840-Q1: Schematic review

Jayden Qiu

Part Number: TPS25840-Q1
Other Parts Discussed in Thread: TPS25830A-Q1,

Tool/software:

Hi Team,

This is FAE Jayden, ZTE is using TPS25830&TPS25840 in their auto project. Could you help support schematic review? Many Thanks.

ZTE applications are:
① TYPE-C interface, using TPS25830 for charging (5V/3.5A), USB BOOT, and data transmission.
② TYPE-A interface, using TPS25840 for charging (5V/3.5A) and data transmission.
③ TYPE-C interface, using TPS25830 for charging (5V/3.5A) and data transmission.
The output inductor L1 of TPS25830 and TPS25840 will be replaced with SRP5030TA-2R2M (2.2uH, 5.5A) in the future.

zxic_usb_tps25840_s0.pdf zxic_usb_tps25830_s0.pdf

Brs

Jayden

over 1 year ago

0 Ke Wang over 1 year ago

TI__Expert 6861 points

Hi Jayden,

Here are some suggestions:

1. The recommended voltage across R6, the current sense resistor, under current limit should be approximately 50 mV as a compromise between accuracy and power dissipation. So you can change R6 from 10 mOhm to 14 or 15 mOhm. Please select the SMT device with proper power rating. 1/8 W is not sufficient in this case.

2. Note when Vin > 19 V, fsw will be set to 420 kHz regardless of the resistors value. When Vin>19V, a 2.2 uH inductor might be too small, and the current ripple could be large. A 10 uH inductor is suggested in this case.

3. Please verify with the customer whether R10+R21, as Rimon, is selected for around 0.33 V/A cable voltage drop compensation.

4. R11+R18=7.4 kOhm, is selected based on 10 mOhm R6. When R6 value is modified, please change R11+R18 to 5.45 kOhm accordingly for around 3.8 A max current limit, according to section 10.3.10.1. RLIMIT=5.91 kOhm for 3.5 A.

Best Regards,

Ke Wang

0 Rubin Chen over 1 year ago in reply to Ke Wang

Intellectual 420 points

Hi Ke，

For the third point,could you please explain about "Rimon is selected for around 0.33 V/A cable voltage drop compensation" in detail？

There is a formula for the value of RIMON in the datasheet. How to determine RWIRE?

0 Ke Wang over 1 year ago in reply to Rubin Chen

TI__Expert 6861 points

Hi Rubin,

Based on the value of R10 + R21, the cable voltage drop compensation should be around 1 V. Considering a maximum 3 A output, the compensation target should be around 0.33 V/A in your current schematic. Please check the cable impedance you will utilize, and whether it matches the compensation target / or the compensation target is suitable for the selected cable. Rwire will be a measured value, or from the cable manufacturer.

BR,

Ke Wang

0 Rubin Chen over 1 year ago in reply to Ke Wang

Intellectual 420 points

Hi Ke,

We select TPS25830&TPS25840 for Type-C and Type-A at present.However，the I/O level of our SOC is 1.2V,level conversion is required.Could you please recommend USB-PD chips of 1.2V I/O level？Whether the chip will be developed later？

Thanks

0 Ke Wang over 1 year ago in reply to Rubin Chen

TI__Expert 6861 points

Hi Rubin,

Currently we do not have products with 1.2V I/O, most of the auto products are based on 1.8V/3.3V . And seems we do not have plan for 1.2 V I/O chip for now.

BR,

Ke Wang

0 Rubin Chen over 1 year ago in reply to Ke Wang

Intellectual 420 points

Hi Ke,

If CTRL1=1,CTRL2=1,is the maximum current=3.5A？

If CTRL1=1，CTRL2=0，what's the maximum current?

Thanks

0 Ke Wang over 1 year ago in reply to Rubin Chen

TI__Expert 6861 points

Hi Rubin,

Please check Table 10-6 and section 10.3.10.1 in tps25840-q1 datasheet.

BR,

Ke Wang

0 Rubin Chen over 1 year ago in reply to Ke Wang

Intellectual 420 points

Hi Ke,

Can TPS25830&TPS25840 implement the OTG function for USB2.0&USB3.1?

Thanks

0 Jayden Qiu over 1 year ago in reply to Rubin Chen

TI__Intellectual 1405 points

Hi Ke,

Good day! Could you help answer this question due to the urgency? Thanks.

Brs

Jayden

0 Ke Wang over 1 year ago in reply to Rubin Chen

TI__Expert 6861 points

Hi Robin,

No, they do not support OTG, some other chip with a bidirectional power path might be needed for this function.

By the way, is this function required for Car play?

BR,

Ke Wang

0 Rubin Chen over 1 year ago in reply to Ke Wang

Intellectual 420 points

Hi Ke,

There are two questions:

①Does the TPS25830 use the CC1&CC1 to determine whether the inserted device is a host or devcie?
②TPS25840 does not have CC1&CC2. How does it determine whether the inserted device is a host or devcie?

These two questions are urgent. I hope you can reply as soon as possible.

Thanks.

0 Ke Wang over 1 year ago in reply to Rubin Chen

TI__Expert 6861 points

Hi Rubin,

1. Yes, please refer to section 10.3.16 in the TPS25830 datasheet.

2. The Client mode is controlled by CTRL1 and CTRL2. Please check section 10.4 in the TPS25840 datasheet.

BR,

Ke Wang

0 Rubin Chen over 1 year ago in reply to Ke Wang

Intellectual 420 points

Hi Ke，

In the Client mode,the external MOSFET power switch is OFF and only the data analog switch is ON.

But I do not see how to identify whether the inserted device is a master or slave device.

Does the TPS25840 support Master-Slave Switchover?

Thanks.

0 Rubin Chen over 1 year ago in reply to Ke Wang

Intellectual 420 points

Hi Ke,

Does the TPS25830 have Client Mode?

Can I use it for factory-only software programming with the USB port?

Thanks.

0 Ke Wang over 1 year ago in reply to Rubin Chen

TI__Expert 6861 points

Hi Rubin,

For TPS25830, the CTRL1 and CTRL2 pins can only set the operating mode implementing Type-C, CDP and SDP USB port configurations. I don't think the factory-only software programming can be done.

For TPS25840, the Master-Slave switchover function is not included in the datasheet.

BR,

Ke Wang

0 Ke Wang over 1 year ago in reply to Rubin Chen

TI__Expert 6861 points

Hi Rubin,

TPS25830A has the client mode and you can do the mentioned program.

BR,

Ke Wang

0 Rubin Chen over 1 year ago in reply to Ke Wang

Intellectual 420 points

Hi Ke,

If TPS25840 does not support the function of Master-Slave switchover.Whethe it supports master or slave?How to design in hardware to distinguish master or slave？

Thanks

0 Rubin Chen over 1 year ago in reply to Ke Wang

Intellectual 420 points

Hi Ke，

When “CTRL1=1”，TPS25830 suppout both power supply and data transmission，I think this is the master.

When "CTRL1=0",there is "RESERVED, DO NOT USE", so how to implement the slave mode?How to implement Master-Slave Switchover?

Thanks.

0 Ke Wang over 1 year ago in reply to Rubin Chen

TI__Expert 6861 points

Hi Rubin,

As I answered last time, for TPS25830 (where I think you got the table you attached), the CTRL1 and CTRL2 pins can only set the operating mode implementing Type-C, CDP and SDP USB port configurations. it does not support Master-Slave switchover.

For TPS25840, check section 10.4.3 in the datasheet for its modes. In hardware, you will need to utilize proper pull-up or pull-down resistors for CTRL1 and CTRL2 pins.

I'll close this thread for now, since the question is unrelated to the schematic review. Please create a new thread if you have additional questions about the "Master-Slave switchover" topic.

BR,

Ke Wang

0 Rubin Chen over 1 year ago in reply to Ke Wang

Intellectual 420 points

Hi Ke，

Could you please tell me what is the purpose of adding 15kΩ pull-down resistors in D+ and D-?Is this necessary?

Thanks

slvube2a.pdf

0 Ke Wang over 1 year ago in reply to Rubin Chen

TI__Expert 6861 points

Hi Rubin,

The purpose of having these two resistors is pulling D+/- out down to GND when needed, please refer to 10.2 Functional Block Diagram in the datasheet. It's not mandatory.

BR,

Ke Wang

0 Rubin Chen over 1 year ago in reply to Ke Wang

Intellectual 420 points

Hi Ke，

Can you provide the reference design for the TPS25830A-Q1 &TPS25840-Q1?

I want to check my schematic diagram.

Thanks

0 Ke Wang over 1 year ago in reply to Rubin Chen

TI__Expert 6861 points

Hi Rubin:

TPS25830A-Q1: https://www.ti.com/tool/PMP30338

TPS25840-Q1: https://www.ti.com/tool/PMP40544

BR,

Ke Wang

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TPS25840-Q1: Schematic review