1. LM324KAPW Substitution Conclusion A direct substitution is feasible, but key performance differences must be noted. Compared to the original LM324WPT, both devices are fully compatible in supply voltage range, input offset voltage, and package. The primary differences are: the TI variant offers a slightly higher slew rate (0.5 V/µs) than the ST variant (0.4 V/µs), resulting in marginally faster large-signal step response. However, the TI variant’s output drive current (30 mA) is notably lower than the ST part’s (40 mA). This indicates that under low-impedance or heavy capacitive loads, the TI device may experience earlier output swing reduction or weaker dynamic performance. Additionally, the TI variant shows slight advantages in input bias current (15 nA) and quiescent current (1.4 mA). In applications where the original part’s maximum output current capability is not fully utilized, and where slight improvements in quiescent current and slew rate are desirable, the LM324KAPW is a suitable substitute. If the original design relies on higher output current margin, performance under load conditions should be re-evaluated.