The work presents the design and implementation of a novel differential band-pass filter topology integrated into an instrumentation amplifier for Electrocardiography (ECG) applications. This topology utilizes an RLC model between the buffer and differential stages, optimizing signal filtering while maintaining accuracy in biological signal acquisition. A key innovation is the incorporation of a generalized Antoniou impedance converter (GIC), to precisely control inductive impedances, allowing for more stable filter performance and enabling high inductance values without the need for bulky components. This approach effectively prevents degradation of the Common Mode Rejection Ratio (CMRR), which is crucial for maintaining signal integrity in noisy environments. The circuit provides significant improvements in signal selectivity and noise rejection by attenuating out-of-band signals, thereby ensuring the clean amplification of differential-mode signals. Extensive simulations and practical implementation validate the circuit’s performance, demonstrating its effectiveness in enhancing ECG data interpretation. This work could have potential applications in biomedical instrumentation, where precise signal processing is essential for accurate diagnosis and monitoring.