Custom CMOS process:
• Semefab was one of the first companies to produce a Photo- ASIC for optical smoke detector applications
• The SF107 is a high performance, low cost, low noise and low power ASIC
• The chip integrates a low capacitance photodiode with amplifiers which are synchronous with the IR pulse to minimise noise and cancel offset

SF 106:
The ASIC is a low current IC providing all the features needed for an infra red optical smoke alarm. This device is designed to be incorporated into an infrared photoelectric chamber so that the scattered light from the smoke particles falls directly on to the integral photodiode. The design facilitates fast calibration and testing of the finished alarm and the low current consumption allows for a ten year battery lifetime. There is also an integrated horn driver on the ASIC. The ASIC is designed to comply with Underwriters Laboratories Inc. specification UL217 and British Standard BS 5446 - 1:2000.

SF 107:
The Semefab SF107 is a high performance,low cost,low noise and low power interface between an optical smoke detector chamber and a microprocessor. The ASIC has been specifically developed for the optical smoke detector market. The device integrates on the same chip a low capacitance photodiode,with amplifiers which are synchronous with the IR pulse to minimise noise and cancel offset. The gain of the last stage of the amplifier can be adjusted by the end user by the use of an external resistor and capacitor.