VTT9812FH / VTT9814FH IR-blocking Silicon Phototransistors

450-700 nm; Peak Spectral Response 585 nm; Active Area 0.192 mm2; Dark Current ≤50 nA; Short Circuit Current 60-120 µA; Sensitivity 7 A/W Typ.

Excelitas’ VTT9812FH and VTT9814FH are silicon phototransistors in an infrared-blocking, flat T 1¾ end-looking package. These phototransistors provide an excellent response in the visible spectral range.

Phototransistors are photodiode-amplifier combinations integrated within a single silicon chip. The phototransistor can be viewed as a photodiode whose output current is fed into the base of a conventional transistor. These photodiode-amplifier combinations are put together to overcome the major limitation of photodiodes: unity gain. The typical gain of a phototransistor can range from 100 to over 1,500.

Many applications demand a greater output than can be generated by a photodiode alone. Even though the signal of a photodiode can be amplified through external circuitry, this is not always cost effective. In such cases, phototransistors provide a lower cost alternative.

The VTT9812FH and VTT9814FH include the time-proven VTT silicon phototransistor chip family that customers have come to rely upon over the years, with the additional IR-blocking feature incorporated in the plastic epoxy package. As such they give an excellent response in the visible spectral range (450 to 700 nm), giving a RoHS-compliant alternative to Cadmium Sulphide photocells.

The VTT9812FH is designed for dusk/dawn switching at low light levels around 0.2 to 1 fc (2 to 10 lux).

With a narrow light current tolerance, the VTT9814FH is especially suited for ambient light control applications around 50 to 100 fc (500 to 1,000 lux).

Key Features:

• Visible Light Response With IR Blocking Feature Incorporated in the Casting Epoxy
• Low Dark Current: Max. 50 nA at 5 V VCE
• RoHS-compliant Alternative to Photocells
• Active Area = 0.192 mm2
• Short Circuit Current = Min. 60 µA (VTT9812FH), 80 µA (VTT9814FH), Max. 120 µA at 100 fc, 2,850 K
• Spectral Range = 450 nm to 700 nm
• Peak Spectral Response = 585 nm
• Sensitivity at Peak Wavelength = 7 A/W Typ.
• Angular Response = ±50° at 50% Response
• Soldering Temperature = Max. +260 °C

Applications: Street Light Switching; Interior and Exterior Light Control (Dusk/Dawn Switch); Automotive Headlight Dimmer; Display Contrast Control; Energy Conservation