LPC845M301JHI48K power consumption issue

[TeemoLi]

Project: OP 40V-3A BMS

         Part number: LPC845M301JHI48K

         Defective rate :    1/1000 PCS

         Temperature:  30 ~  40℃  

         Issue: In the power down mode, a few devices have high power consumption.

                    The abnormal current consumption exceeds 100uA.

                    Normal Power down mode, the current consumption is 15uA.

         Conditional setting：  1) Power down mode    2)When enter the power down mode, set TX_PWR_EN and  P_UART_TX   GPIO mode:  Inactive (no pull-down/pull-up resistor enabled) .    DIRP :  input

Cause : Test TP8, The ripple voltage exceeds 30~80mV. Abnormal currents exceeding 100uA will be generated.

                        Test TP8, The ripple voltage less than 30mV. Normal Power down mode, the current consumption is 15uA.

          Action:   1)Set P_UART_TX  and TX_PWR_EN enter  input mode  and Pull-down resistor enabled. Can solved this issue.

         Explanation need:  

                         TTi want to get the below response from NXP.

The input IO TX_PWR_EN, P_UART_TX in the power down mode. Inactive (no pull-down/pull-up resistor enabled) .    
1.1)30~80mV ripple voltage enter IO TX_PWR_EN and P_UART_TX Pin, why increase in power consumption?( power consumption is  more than 100uA)

        Below 30mV ripple voltage, power consumption is normal (power consumption is 15uA).

       NXP response:  

       1.2) The GPIO voltage ripple input cause in increased power dissipation, what the voltage threshold is?

              NXP response:

       1.3) Please explain in detail why a ripple input of 30~80mV increases the internal working principle of the chip.

              NXP response:

[xiangjun_rong]

Hi,

As you know that the LPC845 supports "switch matrix" feature, can you tell us the pin name for example PIO0_x for the P_UART_TX and TX_PWR_EN? does the pin multiplex with analog channel for example ADC,DAC and CMP?

BR

XiangJun Rong

[TeemoLi]

I have confirm with TTI engineer.
P_UART_TX PIO1_9 switch matrix UART_TX
TX_PWR_EN PIO0_16 input Inactive (no pull-down/pull-up resistor enabled) .

It only open the "UART" switch matrix. The ADC, DAC and CMP switch matrix is closed.
You can reproduce the power consumption problem。
Can you answer three questions from customers?
Explanation need:

TTi want to get the below response from NXP.

The input IO TX_PWR_EN, P_UART_TX in the power down mode. Inactive (no pull-down/pull-up resistor enabled) .
1.1)30~80mV ripple voltage enter IO TX_PWR_EN and P_UART_TX Pin, why increase in power consumption?( power consumption is more than 100uA)

Below 30mV ripple voltage, power consumption is normal (power consumption is 15uA).

NXP response:



1.2) The GPIO voltage ripple input cause in increased power dissipation, what the voltage threshold is?

NXP response:



1.3) Please explain in detail why a ripple input of 30~80mV increases the internal working principle of the chip.

NXP response:

[xiangjun_rong]

Hi,

I have asked AE team for the issue that 30mv~80mV input can increase the chip current, because the Chinese festival, suppose I will answer you after I come back

BR

XiangJun Rong

[TeemoLi]

Because the Defective rate is 1/1000 PCS.I couldn't make sure, wheter can reproduce the problem.
Whether there is an AE message feedback what causes the power consumption abnormality. Thanks!

[TeemoLi · Accepted solution]

Please look at the datasheet.

The customer GPIO status.

GPIO :TX_PWR_EN   EN and  P_UART_TX   GPIO mode:  Inactive (no pull-down/pull-up resistor enabled) .    DIRP :  input.    

This status is in floating status.Very small input ripple voltage 30~80mV. This results in a current consumption of 100UA.    

input ripple voltage less than 30mV， This results is a normal current and consumption is15UA.

I make sure before enter sleep mode, BMS will clear all switch matrix settings, and disable all peripherals except for RST, SWDIO, SWCLK (default state).  IOCON is also turned off after the setup is complete.

demand NXP response：

1:In float status, the input pin, exceeding the threshold of how many mV ripple amplitude will result in increased power dissipation.  

TTI wants NXP to provide a reply, LPC845 chip in the design GPIO accurate how much MV ripple input floating, will lead to increased power consumption.Please give an exact value。Very urgent waiting for a reply。 Thanks!

[TeemoLi]

Dear xiangjun.Rong,

         Any response from AE ? Thanks for your best support.

[TeemoLi]

Dear NXP, 

        Please response power consumption issue ASAP. Thanks.

[TeemoLi]

Please look at the datasheet.

The customer GPIO status.

GPIO :TX_PWR_EN   EN and  P_UART_TX   GPIO mode:  Inactive (no pull-down/pull-up resistor enabled) .    DIRP :  input.    

This status is in floating status.Very small input ripple voltage 30~80mV. This results in a current consumption of 100UA.    

input ripple voltage less than 30mV， This results is a normal current and consumption is15UA.

I make sure before enter power down mode, BMS will clear all switch matrix settings, and disable all peripherals except for RST, SWDIO, SWCLK (default state).  IOCON is also turned off after the setup is complete.

demand NXP response：

1:In float status, the input pin, exceeding the threshold of how many mV ripple amplitude will result in increased power dissipation.  

TTI wants NXP to provide a reply, LPC845 chip in the design GPIO accurate how much MV ripple input floating, will lead to increased power consumption.Please give an exact value。Very urgent waiting for a reply。 Thanks!

[TeemoLi]

Please look at the datasheet.

The customer GPIO status.

GPIO :TX_PWR_EN   EN and  P_UART_TX   GPIO mode:  Inactive (no pull-down/pull-up resistor enabled) .    DIRP :  input.    

This status is in floating status.Very small input ripple voltage 30~80mV. This results in a current consumption of 100UA.    

input ripple voltage less than 30mV， This results is a normal current and consumption is15UA.

I make sure before enter power down mode, BMS will clear all switch matrix settings, and disable all peripherals except for RST, SWDIO, SWCLK (default state).  IOCON is also turned off after the setup is complete.

demand NXP response：

1:In float status, the input pin, exceeding the threshold of how many mV ripple amplitude will result in increased power dissipation.  

TTI wants NXP to provide a reply, LPC845 chip in the design GPIO accurate how much MV ripple input floating, will lead to increased power consumption.Please give an exact value。Very urgent waiting for a reply。 Thanks!

[TeemoLi]

Please look at the datasheet.

The customer GPIO status.

GPIO :TX_PWR_EN   EN and  P_UART_TX   GPIO mode:  Inactive (no pull-down/pull-up resistor enabled) .    DIRP :  input.    

This status is in floating status.Very small input ripple voltage 30~80mV. This results in a current consumption of 100UA.    

input ripple voltage less than 30mV， This results is a normal current and consumption is15UA.

I make sure before enter power down mode, BMS will clear all switch matrix settings, and disable all peripherals except for RST, SWDIO, SWCLK (default state).  IOCON is also turned off after the setup is complete.

demand NXP response：

1:In float status, the input pin, exceeding the threshold of how many mV ripple amplitude will result in increased power dissipation.  

TTI wants NXP to provide a reply, LPC845 chip in the design GPIO accurate how much MV ripple input floating, will lead to increased power consumption.Please give an exact value。Very urgent waiting for a reply。 Thanks!