• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Subscribers 62 subscribers
  • Views 256 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

UCC27524A1-Q1: How do we dealt with the maximum and recommended output current capability: 5A

Yoshiki Ochi
Expert 8245 points
Part Number: UCC27524A1-Q1

Hi team,

Its "Absolute Maximum Ratings" says that "Output pulsed source/sink current (0.5 µs)" is 5A. Does it mean its output pulse (0.5us) current should be lower than 5A?

In addition, "Electrical Characteristics" says that "ISNK/SRC Sink/source peak current(1)" @ "CLOAD = 0.22 µF, FSW = 1 kHz" is 5A. 
Does they mean that the recommended output current @ "CLOAD = 0.22 µF, FSW = 1 kHz, and 0.5 µs high pulse output" is 5A?

Also, how about the output current capability in the case of variated switching frequency or high pulse duration?

Regards,
Ochi

  • 0
    TI__Genius 13445 points

    Ochi-san,

    • "Does it mean its output pulse (0.5us) current should be lower than 5A?"

    No this means that driver IC can only (is designed to be able to) source/sink 5-A for <=0.5us which will also be influenced by external factors such as gate resistor selection, board layout, parasitic, VDD range, etc...

    • "Does they mean that the recommended output current @ "CLOAD = 0.22 µF, FSW = 1 kHz, and 0.5 µs high pulse output" is 5A?"

    No, this simply means specifies the test conditions during which the electrical characteristics data was collected. The driver will source/sink 5-A irrespective of switching frequency but the current capability will be influenced by the factors I listed above.

    • "Also, how about the output current capability in the case of variated switching frequency or high pulse duration?"

    For higher pulse, the driver will source/sink the current during the rise/fall sequences of the OUT pulse. Switching frequency again does not influence current capability of the IC.

    Regards,

    -Mamadou

  • 0 in reply to Mamadou Diallo
    TI__Expert 8245 points

    Hi Mamadou, 

    Could you give me your comment about the red highlighted comment you sent to me in more detail?

    "No, this simply means specifies the test conditions during which the electrical characteristics data was collected. The driver will source/sink 5-A irrespective of switching frequency but the current capability will be influenced by the factors I listed above."

    Do you mean "CLOAD = 0.22 µF, FSW = 1 kHz" is just its test condition and "±5" is electrical characteristics?

    How did you limit sink/source max current within "±5"? Datasheet says "ISNK/SRC Sink/source peak current(1), (1) Ensured by design". Did you use external resistors to control max sink/source current?

    Regards,
    Ochi

  • 0 in reply to Yoshiki Ochi
    TI__Genius 13445 points

    Ochi-san,

    "Do you mean "CLOAD = 0.22 µF, FSW = 1 kHz" is just its test condition and "±5" is electrical characteristics?" Yes, this parameter is ensured by design.

    "How did you limit sink/source max current within "±5"? Datasheet says "ISNK/SRC Sink/source peak current(1), (1) Ensured by design". Did you use external resistors to control max sink/source current?"

    Test conditions does not list a gate resistor therefore there is none. At 12V, that is the typical peak source/sink current you can expect from the IC. If you add a gate resistor, the peak current will be limited to Isrc/snk = VDD / Rgate.

    -Mamadou

  • 0 in reply to Mamadou Diallo
    TI__Expert 8245 points

    Hi Mamadou, 

    I am not clear for abs max and typ sink/source current relationship and how we prevent UCC27524A1-Q1 from exceeding its ass max sink/source current spec.

    • The typical output current is 5A at 12V supply voltage, however, its abs max is 5A for 0.5us.
      Does it mean that typical output current 5A flows the duration <0.5us so it is no problem for this IC?
    • Why does output current is 5Atyp at 12V in spite of no gate resistor? Does UCC277524A1-Q1 has internal current limit circuit for <5A?
      We must use UCC27524A1-Q1 within its abs max rating, but I cannot understand why it is OK for output current (5Atyp) at 12V supply voltage without gate resistor.
    • How does output current change in the case we use VDD=10V without gate resistor? 
      How we calculate max output current without gate resistor? 
      In the case of Isrc/snk = VDD / Rgate > 5A, is output max current is 5A? In the case of  Isrc/snk = VDD / Rgate <= 5A, this calculation is dominant for the output max current? 

    Regards,
    Ochi

  • 0 in reply to Yoshiki Ochi
    TI__Genius 13445 points

    Ochi-san,

    Kindly review the following document.

    www.ti.com/.../slla387a.pdf

    If you have additional questions, I will reach out via email to take it offline.

    Regards,

    -Mamadou