Charge amplifier circuit for a capacitive sensing arrangement

A charge amplifier circuit (10) for a capacitive sensing arrangement (80), the charge amplifier circuit (10) comprising:

• a first amplifier stage (20) comprising a first amplifier input (22), a second amplifier input (23) connectable to the capacitive sensing arrangement (80), and comprising a first amplifier output (24) and a second amplifier output (25),
• a second amplifier stage (30) comprising a first amplifier input (32), a second amplifier input (33), a first amplifier output (34) and a second amplifier output (35), and
• a switched capacitor arrangement (40) between the first amplifier stage (20) and the second amplifier stage (30), the switched capacitor arrangement (40) comprising a first integration capacitor (42), a second integration capacitor (43), a number of first switches (66, 67) and a number of second switches (68, 69),
• wherein the first integration capacitor (42) is selectively connectable to the first amplifier output (24) of the first amplifier stage (20) via one of the second switches (68) and is selectively connectable to the first amplifier input (32) of the second amplifier stage (30) via one of the first switches (66), and
• wherein the second integration capacitor (43) is selectively connectable to the second amplifier output (25) of the first amplifier stage (20) via another one of the second switches (69) and is selectively connectable to the second amplifier input (33) of the second amplifier stage (30) via another one of the first switches (67).