OPF794 Optek, OPF794 Datasheet - Page 24

• Manufacturer Part Number: OPF794
• Description: Photodiodes Pin Photodiode
• Manufacturer: Optek

Specifications of OPF794

• Maximum Reverse Voltage: 100 V
• Maximum Rise Time: 6 ns
• Mounting Style: SMD/SMT
• Product: Photodiode
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PhotoSensors — Diodes, Transistors, Darlingtons
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Product Definitions
ELECTING
HOTODIODES
HOTOLOGIC
HOTOTRANSISTORS AND
PECTRAL
The OPTEK line of photosensors includes four basic infrared-sensitive device types: photodiodes, phototransistors,
photodarlingtons and Photologic® sensors. Each basic type is available in a variety of case styles. For every infrared emitter
made by OPTEK, there is a mechanically and spectrally matched sensor. Case styles include several sizes of hermetic devices, and
an even wider variety of plastic encapsulated types. Plastic versions of the popular hermetic TO-18 part are also available,
offering improved optical design and drop-in replacement at substantial cost savings.
Important factors to consider when selecting the right device for an application are: operating speed required, available infrared
energy, and the desired output current. Depending on the required balance of these design factors, OPTEK offers a choice of
several appropriate types of photosensors
PN junction silicon photodiodes have the fastest operating speed of all the photosensors in the OPTEK product family. Rise and
fall times of 100 nanoseconds are typical for these devices. However, light current (IC) for these devices tends to be low;
therefore, additional amplification is almost always required. Nevertheless, where speed considerations predominate,
photodiodes are the best option.
Photologic® is a term OPTEK uses to refer to complex integrated circuitry combined with a high speed, high sensitivity
photodiode on a single silicon chip. Photologic® devices offer the speed advantage of photodiodes along with a Schmitt trigger
and amplifier to directly drive up to eight TTL loads. Medium speed data rates to 250 kbaud are possible with typical output rise
and fall times of 25 nanoseconds. These devices are excellent choices where speed, accuracy and logic interface are required.
Typical examples include high speed motion encoding, modulated (pulsed) long distance beam interrupt applications, such as
touch screens, and track ball type devices for video games or “mouse” applications for computer accessories.
Phototransistors and photodarlingtons are OPTEK’s most widely used photosensor types. For most traditional applications, NPN
silicon phototransisitors offer the best value in terms of output current, sensitivity, speed, reliability and quality. Devices with
minimum on-state collector currents ranging up to 40 mA are available, while output rise and fall times of 60-100 microseconds
(RL=5 KW) are typical. OPTEK phototransistors are 100 percent tested and specified at light levels which range upwards from
1.00mW/cm2 with collector-to-emitter voltage (VCE) set at 5.0 volts.
Photodarlingtons provide the higher sensitivity and gain needed for many applications; however, rise and fall times are slower.
When switching time is not critical, the choice of a photodarlington can offer improved sensing reliability and reduce the need for
additional signal amplification.
OPTEK scientists and engineers continue to advance the state-of-the-art in Photologic® monolithic optoelectronic IC’s, a product
originally conceived and developed by OPTEK. The next generation of Photologic® devices will include substantially increased
sensitivity, making longer beam distances possible and offering even higher reliability at lower irradiance levels. Direct TTL and
CMOS compatibility is also featured with increased sink/source capability. Supply voltage requirements are more flexible than
before due to an on-chip voltage regulator designed by OPTEK. And finally, the new Photologic® devices will offer a choice of
two hysteresis ratios [EeT(+)/EeT(-)] of 2 and 1.4. With these new advancements, OPTEK continues its leadership role in advanced
photosensor design.
OPTEK photosensors are spectrally matched to the OPTEK line of infrared emitting diodes. The output peak wavelengths for both
GaAs and GaAlAs lie very close to the silicon sensitivity peak of about 850 nanometers.
EADERSHIP IN
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Issue A.1 2005
OPTEK Technology Inc. www.optekinc.com