BL59S12

www.DataSheet4U.com BL59A12/BL59S12 PHOTOELECTRIC SMOKE DETECTOR IC 1. Product description 1.1 Basic function: BL59A12 (BL59S12) is a CMOS LSI used for smoke detection. Ultra-low power analog and digital circuits are contained in it. Combined with an IR photoelectric chamber, this IC is used to detect smoke through receiving light scattered by tiny smoke particles going into the chamber. When smoke is detected, a burst of alarm sounds are generated by an external piezoelectric buzzer driven by the push-pull output of this IC. 1.2. Applications: Smoke detection system. 2. Features: Power supply range: 6V ～ 12V Average supply current: 8uA Operating temperature range: -10 ～ 60℃ Ideal for battery powered applications. 3. Block diagram of this IC 4.Pin assignment http://www.belling.com.cn -1- 8/28/2006 Wrote by 2006 Total 8 Pages BL59A12/BL59S12 5.Pin description Pin Symbol No. 1,2 C1, C2 Input/output External capacitor connection I Detecting input Strobe Power supply O Output signal Functions By connecting external capacitor, a voltage feedback amplifier is formed. The gain of it is determined by capacitor’s value. Connect a photodiode to supply a signal to the internal comparator. A strobe voltage output, referenced to VDD. When output = VDD -5V, it enables other internal circuits. To supply the power To output pulse drive signal for external NPN transistor which drives a IR photodiode. It can be used to connect up to 40 detectors to make auxiliary alarm, remote alarm, au...