900 nA supply — the part that doesn't drain the battery
Its headline draw is 900 nA typical supply current, which puts it firmly in the nanopower class — think battery-monitor front-ends, wearable sensor amplifiers, or always-on threshold detectors that run for years on a coin cell. Input bias current is 100 pA typical, so high-impedance sources like photodiodes or pH probes won't see a significant loading error.
5.5 kHz gain-bandwidth — what you trade for the low power
The 5.5 kHz gain-bandwidth product and 0.0025 V/µs slew rate are the speed you give up to get that 900 nA quiescent current. This part will not drive a speaker or close a fast servo loop. What it will do is condition a 10 Hz temperature sensor output or buffer a slow electrochemical cell signal with negligible power cost. If your design needs to filter a 1 kHz signal, the TLV2401IDR won't have the loop gain — you'd step up to the TLV9351IDCKR (3.5 MHz GBW, 600 µA supply) and pay the power penalty.