TUSB8041: Low power Mode question

Vincent Li00

Intellectual 2035 points

Part Number: TUSB8041

Hi Guys

Our customer found that the our TUSB8041A power loss is too high. Just to verify if their application is correct. Their system board input is 42V, which is not our device input. Their operating system is Android8.1, 42V power supply, TUSB8041A is connected to the system's usb3.0 host, and the four ports of TUSB8041A are not connected to any usb device.

         (1) When the system is running:
         If the sys node power/control of usb3.0 corresponding to TUSB8041A is set to auto (allowing the hub to automatically sleep), the input current of the system is about 80mA;
         If the sys node power/control of usb3.0 corresponding to TUSB8041A is set to on (hub is not allowed to sleep automatically), the input current of the system is about 100mA.
         From the above results, if set to auto, the hub should be automatically dormant.
         (2) When the system is standby:
         When the TUSB8041A is powered by V3.3 and V1.1, the input current of the system is approximately 30mA(System input is 42V);
         When the TUSB8041A is powered off V3.3 and V1.1, the input current of the system is approximately 27mA(System input is 42V);

so if we calculate it by 42V, the power loss gap is around 126mW. so our device is about 120mW power loss at standby mode? could you help us check the schematic whether our system is something wrong? I will send you the schematic by email.

Thanks

-Pengfei

over 6 years ago

0 Vincent Li00 over 6 years ago

TI__Intellectual 2035 points

Or, could you explain how to make sure we have got into low power mode? stsOutputEn is just a status show, not a enable switch. So we need to switch to low power mode, how to get in this mode.

Thanks

-Pengfei

0 Gerasimos Madalvanos over 6 years ago in reply to Vincent Li00

TI__Mastermind 32991 points

Hello Pengfei,

Could you provide a system block diagram? My suspicion is that the hub is not entering standby mode as it still is connected to the host upstream. If it sees the termination and connects to the upstream host, the current consumption will be different than if there is no host present and the TUSB8041A is completely disconnected.

Best,
Gerasimos

0 Vincent Li00 over 6 years ago in reply to Gerasimos Madalvanos

TI__Intellectual 2035 points

I can send you the schematic by email.

We did connect the Hub to the host upstream. When we tested it, the difference is only 3.3Vdd and 1.1Vdd power on and power off. The Hub had been connected to the host upstream. But we found the situation has 3mA gap between 3.3 and 1.1 power on and power off. and the input of system is 42V. So the power loss is about 126mW. this is our question, has it entered the standby mode when 3.3V and 1.1V power on? if yes, why is there so much gap when we powered off 3.3V and 1.1V?

So how to control the device fully enter standby mode?

Thanks

-Pengfei

0 Vincent Li00 over 6 years ago in reply to Gerasimos Madalvanos

TI__Intellectual 2035 points

Hi Gera

Could you tell me your email address? Or you can also tell me how to search your name at inforlink?
Thanks

-pengfei

0 Gerasimos Madalvanos over 6 years ago in reply to Vincent Li00

TI__Mastermind 32991 points

Pengfei,

I understand you were connected to the host. Unless the host is in hibernate or the host is disconnected, TUSB8041A will not enter any of it's low power modes. You can not have the host connected to the TUSB8041A and have it be in any of the low power modes specified in the datasheet. If you would still like to send me the schematic, please accept my friendship request on E2E and send it through a direct message there.

Best,
Gerasimos

0 Vincent Li00 over 6 years ago in reply to Gerasimos Madalvanos

TI__Intellectual 2035 points

Hi Gera

thanks for your review on my schematic. As you mentioned, the power loss should be ~42mW. So there should be some issue here. Please see below the plug 2.0 and 3.0 device log file. Whether it is correct way? Or what issue to my device?

When the hub is inserted into a usb device, the hub_suspend and hub_resume functions are called from the log, especially the usb2.0 device.
The attachments are the kernel log when inserting a usb2.0 device and inserting a usb3.0 device.

plug 2.0 device log.txt

Fullscreen Plug 3.0 device log.txt Download

[ 2318.474353] usb usb4: usb wakeup-resume
[ 2318.474404] usb usb4: usb auto-resume
[ 2318.474439] hub 4-0:1.0: hub_resume
[ 2318.474460] hub 4-0:1.0: hub_resume
[ 2318.474580] usb usb4-port1: status 0263 change 0000
[ 2318.474633] hub 4-0:1.0: state 7 ports 1 chg 0000 evt 0000
[ 2318.474721] hub 4-0:1.0: hub_suspend
[ 2318.474744] hub 4-0:1.0: hub_suspend
[ 2318.474823] usb usb4: bus auto-suspend, wakeup 1
[ 2318.474852] usb usb4: bus suspend fail, err -16
[ 2318.474903] hub 4-0:1.0: hub_resume
[ 2318.474923] hub 4-0:1.0: hub_resume
[ 2318.475003] usb usb4-port1: status 0203 change 0000
[ 2318.475048] hub 4-0:1.0: state 7 ports 1 chg 0002 evt 0000
[ 2318.485558] usb 4-1: usb wakeup-resume
[ 2318.485639] usb 4-1: finish resume
[ 2318.485892] hub 4-1:1.0: hub_resume
[ 2318.485917] hub 4-1:1.0: hub_resume
[ 2318.486081] usb 4-1-port2: status 0203 change 0001
[ 2318.588913] usb usb4-port1: resume, status 0
[ 2318.588941] usb usb4-port1: status 0203, change 0000, 5.0 Gb/s
[ 2318.588977] hub 4-1:1.0: state 7 ports 4 chg 0004 evt 0000
[ 2318.589074] usb 4-1-port2: status 0203, change 0000, 5.0 Gb/s
[ 2318.655678] usb 4-1.2: new SuperSpeed USB device number 3 using xhci-hcd
[ 2318.675064] usb 4-1.2: udev 3, busnum 4, minor = 386
[ 2318.675095] usb 4-1.2: New USB device found, idVendor=2109, idProduct=0713
[ 2318.675139] usb 4-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 2318.675168] usb 4-1.2: Product: General
[ 2318.675193] usb 4-1.2: Manufacturer: External SSD
[ 2318.675228] usb 4-1.2: SerialNumber: 0201000000001300
[ 2318.694858] scsi host0: uas
[ 2318.696216] hub 4-1:1.0: state 7 ports 4 chg 0000 evt 0004
[ 2319.326723] scsi 0:0:0:0: Direct-Access     RUIREN T ECH SSD 120G     Q112 PQ: 0 ANSI: 6
[ 2319.330224] sd 0:0:0:0: [sda] 234441648 512-byte logical blocks: (120 GB/112 GiB)
[ 2319.330390] sd 0:0:0:0: Attached scsi generic sg0 type 0
[ 2319.332382] sd 0:0:0:0: [sda] Write Protect is off
[ 2319.332438] sd 0:0:0:0: [sda] Mode Sense: 2f 00 00 00
[ 2319.332880] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 2319.333086] xhci-hcd xhci-hcd.6.auto: ERROR Transfer event for disabled endpoint or incorrect stream ring
[ 2319.333135] xhci-hcd xhci-hcd.6.auto: @00000000f704c2a0 00000000 00000000 1b000000 030b8000
[ 2319.337664] sda: sda1
[ 2319.341242] sd 0:0:0:0: [sda] Attached SCSI disk
rk3399_navigation:/ #

Thanks

-Pengfei

0 Gerasimos Madalvanos over 6 years ago in reply to Vincent Li00

TI__Mastermind 32991 points

Hello Pengfei,

Your logs confirm my assumption that the hub is not in suspend mode, or at least not staying in suspend mode. The upstream device keeps polling the hub and the hub is toggling between suspend and wake mode. This is reflected in your power consumption. If the hub is not entering suspend mode and staying in suspend mode, you will not be able to measure the power consumption in suspend mode. This looks like a software issue where one of the bits on the ports is not cleared or the upstream port is continually polling the hub and waking it up.

If the host is in S4 mode you can force the suspend mode, or if you disconnect VBUS from the hub to force a disconnect from the host you should be able to force disconnect mode and obtain your low power current measurement.

Best,
Gerasimos

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TUSB8041: Low power Mode question