Hello,
Is it safe to have a 5V voltage at the input of the device when the device is not powered? Will there be no issues or permanent damage if this happens?
Thank you!
HI Elisha,
Please refer to section 6.1 Absolute Maximum Ratings table of the OPA2317 on page 5 of the datasheet (below).
The OPA2317 input terminals are diode-clamped to the power-supply rails. If the Inputs will be exposed to voltages pf +0.3 V above the supply rail (V+), the inputs must be current-limited to 10 mA or less. Essentially, if the (V+) supply is held at 0-V, and the input pin voltage is forced to 5-V, internal ESD cell (diode clamp) will turn on and will attempt to hold the input voltage to ~0.5V. If the (V+) supply is held at 0-V and the input is forced to +5V, a large amount of current will flow through the internal diode clamp and damage the structure.
You may need to add series resistors or an external clamp so the inputs are not forced to a voltage above (V+)+0.3V or to ensure the input current is limited to less than <10mA at the inputs during the fault condition. For example, if the user configures the amplifier in the buffer configuration, and the amplifier input is exposed to 5-V while the (V+) is set to 0-V, the user will need to add a series resistor of ~2-kOhm at the non-inverting terminal of the OPA2317 to limit the current flow to less than ~4.7V / 2kOhm = 2.4mA, avoiding damage of the internal diode clamp.
For more information or examples on this subject, please refer to the Precision Labs Session below.
TI Precision Labs - Op Amps: Electrical Overstress (EOS) (Sessions 12.1-12.4)
https://training.ti.com/ti-precision-labs-op-amps-electrical-overstress-eos-1
Thank you and Regards,
Luis
