Time division interleaving band-pass filter for use in voice activity detection

A band-pass filter, comprising a coupling capacitor, a first transistor, a first filtering channel array, a first current source and a second current source, wherein the coupling capacitor is connected to a gate of the first transistor, a source of the first transistor is connected to an output of the first current source, a drain output of the first transistor is connected to both the first filtering channel array and the second current source and is grounded downstream the second current source;

• wherein the band-pass filter further comprises a second transistor and a second filtering channel array;
• the second transistor has a gate input connected to the drain output of the first transistor, a source that is grounded, and a drain connected to both the output of the first current source and the second filtering channel array;
• each of the first and second filtering channel arrays comprises a plurality of filtering channels each comprising a capacitor that is grounded and a switch connected to the capacitor, and the switch is controlled by a pulse signal of a phase φi, where i is an integer in a range of 0-N, and wherein each filtering channel in the first filtering channel array is paired with a corresponding filtering channel of a same phase (φi in the second filtering channel array to form a band-pass filtering channel.