1. LM348D Substitution Conclusion The LM348D is package-compatible with the original LM324ADR2G (both 14-SOIC). However, its supply voltage range (8 V to 36 V) has a significantly higher minimum than the original (3 V to 32 V). If the original design operates at low voltage (e.g., 3–8 V), the LM348D may fail to function or cause system malfunction. Additionally, the LM348D’s output current rating (25 mA) is lower than the original’s 40 mA, which could result in insufficient drive capability, especially under heavy loads. Its supply current (2.4 mA per channel) is also higher than the original (1.5 mA per channel), increasing system power consumption. Although the LM348D shows slight improvements in input bias current (30 nA vs. 40 nA) and input offset voltage (1 mV vs. 2 mV), and shares the same gain bandwidth product (1 MHz), the mismatches in key parameters limit its suitability to applications with higher supply voltages and lower output current demands. Substitution requires careful evaluation of supply and load conditions.