Post Go back to editing

Сurrent consumption ADUM141E and ADUM1401

Hi,

The client is using ADUM1401, but he wants to change to a newer ADUM141E. But he says that AdUM141E has a higher current consumption than ADUM1401, and a lot of heat dissipation. 
Data rate 2 MHz, continuous data transfer mode. Source of 8 channels.

At their speed, the microcircuit is not able to withstand the heat dissipation requirements.

How can this problem be solved? Why is ADUM141E more heat dissipated at the same speed?

Thanks in advance!

Best regards, 

Vitaly

Parents
  • Hi Vitaly,

    The ADuM1401 and ADuM141E are different architectures. The ADuM1401 is an edge based encoding and the ADuM141E is On-Off Keying (OOK). The ADuM1401 will consume less power at data rates < 2Mbps. The ADuM141E will consume much less power at data rates >10Mbps and is a more EMC robust isolator. At 2MHz (4Mbps) the application is close to where power consumption would expected to be similar.

    If power consumption is the application's primary concern, the lowest power consumption for that socket will be the MAX22445. 

    Regards,

    Jason

  • Jason, Good afternoon!

    Thank you very much for your answer.

    The engineer carried out additional tests. EXP board is connected to a laboratory power supply unit, 5 V is set, current measurement on GW Instek GDM-78231.
    Experiment Results:

    exp 1: ADUM1401 - 8 pcs                                        - 5V - 0,2098 A = 1.049 W

    exp 2: ADUM1401 - 7 pcs +  ADUM141E1 - 1 pcs  - 5V - 0,2145 A = 1.072 W

    exp 3: ADUM1401 - 6 pcs + ADUM141E1 -  2 pcs  - 5V - 0,2193 A = 1.096 W

    resulting in + ~ 0.005A (+ ~ 0.025W) when changing from ADUM1401 to ADUM141.
    by 8 pcs - + ~ 0.2W for this device permissible increase in power.

    Is the data obtained by the engineer similar to the data from the documentation for microcircuits?

    The decoupling ADUM1301, ADUM1401, ADUM1402 had a latching problem, as a result of which it caused increased current consumption and heating of ADUMa, this was solved by limiting the supply through a 100 Ohm resistor.

    Question about ADUM141, Could the ADUM141 have such problems or were you able to solve these problems?


    As far as we understand, the snapping came from static, for example, when we check the signals with an oscilloscope, it can snap, or touch the board with a "charged" static, it can snap.

    I would be grateful if you can answer the questions above.

    Regards,

    Vitaliy

Reply
  • Jason, Good afternoon!

    Thank you very much for your answer.

    The engineer carried out additional tests. EXP board is connected to a laboratory power supply unit, 5 V is set, current measurement on GW Instek GDM-78231.
    Experiment Results:

    exp 1: ADUM1401 - 8 pcs                                        - 5V - 0,2098 A = 1.049 W

    exp 2: ADUM1401 - 7 pcs +  ADUM141E1 - 1 pcs  - 5V - 0,2145 A = 1.072 W

    exp 3: ADUM1401 - 6 pcs + ADUM141E1 -  2 pcs  - 5V - 0,2193 A = 1.096 W

    resulting in + ~ 0.005A (+ ~ 0.025W) when changing from ADUM1401 to ADUM141.
    by 8 pcs - + ~ 0.2W for this device permissible increase in power.

    Is the data obtained by the engineer similar to the data from the documentation for microcircuits?

    The decoupling ADUM1301, ADUM1401, ADUM1402 had a latching problem, as a result of which it caused increased current consumption and heating of ADUMa, this was solved by limiting the supply through a 100 Ohm resistor.

    Question about ADUM141, Could the ADUM141 have such problems or were you able to solve these problems?


    As far as we understand, the snapping came from static, for example, when we check the signals with an oscilloscope, it can snap, or touch the board with a "charged" static, it can snap.

    I would be grateful if you can answer the questions above.

    Regards,

    Vitaliy

Children
  • Hi Vitaliy, 

    It sounds like reasonable results. The exact current consumption with the ADuM141E will depend on the signal itself. Refer to Figure 22 & 23 in the ADuM141E datasheet, and note that the transmitter is active when the input is in the non-default state of the device. The isolator channel is consuming more power when the transmitter is active. 

    Some application may require a certain default state (Default state is the state an output goes to if the other side of the isolator becomes undervotlage). Other applications may be able to choose based on power consumption. For example, if the 4 signals spend on average more time high, the ADuM141E1 would have lower power consumption.  

    The ADuM1401 and ADuM141E are completely different designs. The ADuM141E is generally more robust, but I can't say if it will respond differently. But like an IC, there is the possibility of latch up. I would leave the current limiting resistor in place if there is enough power from source available to violate the thermal derating curve in case of a latch-up event. 

    Regards,

    Jason 

  • Jason, 

    Thanks a lot for your help!