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1、Document Number: MC145012 Rev 9.0, 11/2006 Freescale Semiconductor Technical Data Freescale Semiconductor, Inc., 2006. All rights reserved. Photoelectric Smoke Detector IC with I/O and Temporal Pattern Horn Driver The CMOS MC145012 is an advanced smoke detector component containing sophisticated ver
2、y-low-power analog and digital circuitry. The IC is used with an infrared photoelectric chamber. Detection is accomplished by sensing scattered light from minute smoke particles or other aerosols. When detection occurs, a pulsating alarm is sounded via on-chip push-pull drivers and an external piezo
3、electric transducer. The variable-gain photo amplifier allows direct interface to IR detectors (photodiodes). Two external capacitors, C1 and C2, C1 being the larger, determine the gain settings. Low gain is selected by the IC during most of the standby state. Medium gain is selected during a local-
4、smoke condition. High gain is used during push-button test. During standby, the special monitor circuit which periodically checks for degraded chamber sensitivity uses high gain also. The I/O pin, in combination with VSS, can be used to interconnect up to 40 units for common signaling. An on-chip cu
5、rrent sink provides noise immunity when the I/ O is an input. A local-smoke condition activates the short-circuit-protected I/O driver, thereby signaling remote smoke to the interconnected units. Additionally, the I/O pin can be used to activate escape lights, enable auxiliary or remote alarms, and/
6、or initiate auto-dialers. While in standby, the low-supply detection circuitry conducts periodic checks using a pulsed load current from the LED pin. The trip point is set using two external resistors. The supply for the MC145012 can be a 9.0 V battery. A visible LED flash accompanying a pulsating a
7、udible alarm indicates a local- smoke condition. A pulsating audible alarm with no LED flash indicates a remote- smoke condition. A beep or chirp occurring virtually simultaneously with an LED flash indicates a low-supply condition. A beep or chirp occurring halfway between LED flashes indicates deg
8、raded chamber sensitivity. A low-supply condition does not affect the smoke detection capability if VDD 6.0 V. Therefore, the low-supply condition and degraded chamber sensitivity can be further distinguished by performing a push-button (chamber) test. Features Circuit is designed to operate in smok
9、e detector systems that comply with UL217 and UL268 Specifications Operating Voltage Range: 6.0 V to 12 V, Average Supply Current: 8 A Operating Temperature Range: -10 to 60C I/O Pin Allows Units to be Interconnected for Common Signalling Power-On Reset Places IC in Standby Mode (Non-Alarm State) El
10、ectrostatic Discharge (ESD) and Latch Up Protection Circuitry on All Pins Chip Complexity: 2000 FETs, 12 NPNs, 16 Resistors, and 10 Capacitors Supports NFPA 72, ANSI S3.41, and ISO 8201 Audible Emergency Evacuation Signals Ideal for battery-powered applications Pb-Free Packaging Designated by Suffix
11、 Codes ED and EG ORDERING INFORMATION DeviceTemp. RangeCase No.Package MC145012P -55 to +125C 648-08 16 Lead Plastic Dip MC145012ED16 PDIP (Pb-Free) MC145012DW 751G-04 16 Lead SOICW MCZ145012EG/R216 SOICW (Pb-Free) MC145012 PHOTOELECTRIC SMOKE DETECTOR IC WITH I/O AND TEMPORAL PATTERN HORN DRIVER P
12、SUFFIX ED SUFFIX (PB-FREE) PLASTIC DIP CASE 648-08 16 15 14 13 12 11 10 9 1 2 3 4 5 6 7 8 C1 C2 DETECT STROBE VDD IRED I/O BRASS TEST LOW-SUPPLY TRIP VSS R1 OSC LED FEEDBACK SILVER DW SUFFIX EG SUFFIX (PB-FREE) SOIC PACKAGE CASE 751G-04 Figure 1. Pin Connections w w w .l e d -i c s .c o m 0755-82536
13、500 Sensors 2Freescale Semiconductor MC145012 Figure 2. Block Diagram Temporal Pattern Horn Modulator And Driver + - + -DETECT OSC R1 TEST STROBE LOW-SUPPLY TRIP 3 12 13 16 4 15 21 C1C2 OSC AMP COMP COMP Alarm Logic VDD - 5 V REF Timing Logic VDD - 3.5 V REF Zero Gain Low Supply Smoke Gate On/off GA
14、TE ON/OFF 8 9 10 6 11 7 Pin 5 = VDD Pin 14 = VSS LED IRED FEEDBACK SILVER BRASS I/O w w w .l e d -i c s .c o m 0755-82536500 Sensors Freescale Semiconductor3 MC145012 Table 1. Maximum Ratings All voltages are with respect to ground unless otherwise noted. Exceeding these ratings may cause a malfunct
15、ion or permanent damage to the device. (Voltages referenced to VSS) RatingSymbolValueUnit DC Supply VoltageVDD-0.5 to +12V DC Input Voltage C1, C2, Detect Osc, Low-Supply Trip I/O Feedback Test VIN -0.25 to VDD +0.25 -0.25 to VDD +0.25 -0.25 to VDD +10 -15 to +25 -1.0 to VDD +0.25 V DC Input Current
16、, per PinIIN10mA DC Output Current, per PinIOUT25mA DC Supply Current, VDD and VSS PinsIDD+25 / -150mA Power Dissipation in Still Air 5 Seconds Continuous PD 1200 (1) 350 (2) mW Storage TemperatureTSTG-55 to +125C Lead Temperature, 1 mm from Case for 10 SecondsTL260C Peak Package Reflow Temperature During Reflow (3) , (4) TPPRT Note 4 C Note: 1. Derating: -12 mW/C from 25 to 60C 2. Derating: -3.5 mW/C from 25 to 60C. This device contains protection circuitry to guard against damage due to
