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LM2901-N: Transient reverse Vcc of LM2901

Satoshi
Guru 19495 points
Part Number: LM2901-N

Please let me know about the case of Vcc<GND transient condition below.

①When transient time is very short(ex, 10ns), is this possibility to damage?

②If no damage, is there tolerance spec of "GND-Vcc" and transient time?

【Background】

・Customer is using Vcc:+15V and GND:-15V

・When -15V power supply is damage by customer accident, they worry about Vcc move Vcc<GND for the moment.

Best regards,

Satoshi

  • 0
    TI__Mastermind 49966 points

    Hello Satoshi,

    Damage can be occur in picoseconds. There is not a defined "time" limit for damage. It's all about the energy dissipated.

    For this device family, the worst thing to do is to bring ANY pin below the GND pin, since thisd device does NOT have internal ESD clamping diodes. Internal ESD diodes provide a defined path for reverse voltages. Since this device does NOT have ESD diodes, the internal die junctions and body diodes absorb the currents - which is not good..

    In the actual applications, a fast pulse (<10ns) would usually be softened by the bypass capacitor - assuming it is ceramic and near the supply pin.

    If they expect this error condition to occur, then an external Schottky clamp diode should be placed on each supply to GND to clamp any reverse supply transients to less than -300mV. The diodes also keep the supply from "floating" or being pulled opposite by the other supply through circuit paths.

    Regards,