NMOS linear image sensors are self-scanning photodiode arrays designed specifically as detectors for multichannel spectroscopy. The scanning circuit is made up of N-channel MOS transistors, has low power consumption and is easy to handle. Each photodiode has a large active area, high UV sensitivity yet very low noise, delivering a high S/N even at low light levels. Current output type NMOS linear image sensors also offer excellent output linearity and wide dynamic range. S3901-256FX image sensor is variants of S3901-F series NMOS image sensors. Having a phosphor-coated fiber optic plate (FOP) as the light input window, the S3901-256FX was developed for detection of X-rays and electrons. The S3901-256FX offers particularly high sensitivity to X-rays from 10 k to 100 keV. The phosphor material used is gadolinium ox sulfide (Gd2O2S:Tb) whose composition is carefully selected to provide optimum sensitivity and resolution with a peak emission at 550 nm wavelength. The S3901-256FX active area consists of a photodiode array with pixels formed at 50 μm pitches and a height of 2.5 mm. Hamamatsu S3904 series NMOS linear image sensors are also available with FOP windows coated with the same phosphor material as S3901-256FX. Using photodiodes with no phosphor and FOP window also allows direct detection of X-rays at energy levels below 10 keV.
Features
- Wide active area
- Low dark current and high saturation charge allow a long integration time and a wide dynamic range at room temperature
- Excellent output linearity and sensitivity spatial uniformity
- Lower power consumption: 1 mW max.
- Start pulse and clock pulses are CMOS logic compatible