Phototransistors

All phototransistors are based on a photodiode as the photon-to-current converter but include an emitter diffusion creating an npn transistor. The current produced by the photodiode is increased by the hFE of the transistor structure yielding light currents in the milliamp to tens of milliamps. However, the speed-of-response of the photodiode is compromised by the transistor structure with the internal base resistance and the base-collector capacitance (rb-b’ CC) time constant being the primary driver.

Phototransistors have been a primary sensor for decades and continue to be the sensor-of-choice when speed is not of primary importance, but there is need for significant output light current.

Part (1) NumberIL mA (min)at Ee (2) mW/cm2V(BR)CEO(3)V (min)ƟHP (4)deg. (typ)ID (5) nA (max)
  CLT1300.61.5304025
  CLT1311.21.5304025
  CLT1322.41.5304025
  CLT1334.01.5304025
  CLT130W0.41.5307025
  CLT131W1.01.5307025
  CLT132W2.51.53070100
  CLT1352.51.02518100
  CLT3353.01.0 (6)2518100
  CLT435 1.01.0 (7)2518100

Notes:

  1. Click on part number for datasheet.
  2. Radiation source is a 940nm IRED. VCE=5V.
  3. Measured at IC=100mA.
  4. Acceptance angle at half power points.
  5. Measured under dark conditions,  VCE=10V.
  6. A dark condition exists when further irradiation shielding does not reduce ID
  7. Radiation source is a 850nm IRED. VCE=5V.
  8. Radiation source is a 660nm LED. VCE=5V.