PROBLEM TO BE SOLVED: To provide an integrated circuit, a photon detection device, and a radiation analyzer capable of adjusting the gain of an output current in a wide bandwidth while preventing a power consumption.SOLUTION: The integrated circuit has a diverting section and a gain adjustment section. The diverting section diverts an input current into plural current route. The gain adjustment section adjusts the gain of the current input from the diverting section by synthesizing the currents, which are diverted into plural current routes by the diverting section, in a combination according to a first gain adjustment signal from the outside, or by changing the diverting ratio on which the diverting section diverts the current into plural current routes according to the first gain adjustment signal.SELECTED DRAWING: Figure 1【課題】消費電力を抑えつつ、広帯域で出力電流の利得を調整することができる集積回路、光子検出装置、及び放射線分析装置を提供する。【解決手段】実施形態の集積回路は、分流部と、利得調整部とを有する。分流部は、入力された電流を複数の電流経路に分流する。利得調整部は、分流部が複数の電流経路に分流した電流を外部からの第１利得調整信号に応じた組合せで合成すること、又は分流部が複数の電流経路に電流を分流する分流比を第１利得調整信号に応じて変更することにより、分流部に入力された電流の利得を調整する。【選択図】図１
