2. TL084CPT Substitution Conclusion The TL084CPT is a JFET-input operational amplifier, differing from the original general-purpose standard architecture, and substitution should be approached with caution. Its advantages include very low input bias current (20pA vs. 100nA), making it suitable for high-impedance signal sources, and significantly lower quiescent current (approximately 5.6mA total for four channels), which benefits low-power designs. However, notable drawbacks exist: the minimum operating voltage is 6V (versus 3V for the original), limiting its use in low-voltage applications; the input offset voltage is relatively high (3mV), which may affect DC accuracy. Although the slew rate (16V/µs) and output current (40mA) are higher, the JFET characteristics may lead to mismatches in common-mode voltage range, noise performance, and other aspects compared to the original design. If the system supply is ≥6V and high input impedance is required, substitution is possible, but circuit performance should be re-verified.