An
amplifier circuit for a
radiation detector comprises an input node (401) for receiving a charge
signal from said
radiation detector and an
amplifier (402). The input of the
amplifier (402) is coupled to said input node (401) . An output node (403) is coupled to the output of the amplifier (402). A
capacitive coupling (404, 504, 604, 804, 904, 1304, 1404) is coupled between the input and output of the amplifier (402). A reset switch (405) is coupled across said
capacitive coupling (404, 504, 604, 804, 904, 1304, 1404). The
capacitive coupling (404, 504, 604, 804, 904, 1304, 1404) comprises at least two capacitors (406, 407, 501, 502, 801, 802, 803, 1301, 1302, 1306, 1307, 1401) coupled in series and a shunt switch (408, 503, 601, 805, 806, 901, 1303, 1305). The shunt switch (408, 503, 601, 805, 806, 901, 1303, 1305) is coupled across a respective one of said at least two capacitors (406, 407, 501, 502, 801, 802, 803, 1301, 1302, 1306, 1307, 1401).