MC145012P Photoelectric Smoke Detector IC | NXP
N.º de pieza: MC145012P ✗ Fin de vidaMC145012P Descripción general
A photoelectric smoke detector is a safety sensor that detects airborne smoke or other aerosols through light scattering. The MC145012 integrates low-power analog and digital circuitry, an infrared sensing interface, an I/O connection for unit interconnections, and the timing and drive functions required for a pulsed horn. This places the component within the hierarchy of sensor interface IC, smoke detector circuit, alarm-system component, and integrated circuit.
The principal functional features are photoelectric chamber support, I/O capability, and temporal-pattern horn drive. The low average supply current of 8 µA is particularly important for battery-backed household alarms because it reduces standby energy consumption. The 6 V to 12 V operating range is compatible with common alarm-system supply arrangements, while the I/O pin provides a path for coordinating interconnected smoke alarms.
Internally, the device combines sophisticated very-low-power analog circuitry with digital control and timing functions. Detection occurs when scattered infrared light from smoke particles or other aerosols reaches the sensing input. The detector circuitry evaluates this signal and, upon a detected alarm condition, causes the horn output to follow a pulsating temporal pattern. The manufacturer identifies the circuit as designed for operation in compliance with UL217 and UL268.
Typical applications include residential photoelectric smoke alarms, interconnected smoke-alarm networks, commercial building alarm panels, and low-power battery-operated safety products. The same device can serve both single-unit and interconnected alarm designs because its I/O pin supports coordination between multiple detectors, while the horn-driver section provides the required temporal signaling output.
A key implementation consideration is the relationship between the chamber, analog signal path, and alarm timing. Component placement, grounding, supply bypassing, and the external chamber interface should follow the manufacturer application circuit to preserve low-noise detection and reliable alarm signaling. The plastic DIP package also requires adequate spacing from heat sources and careful observation of lead orientation during assembly.
This product summary consolidates the manufacturer identification, functional description, operating limits, package information, and design intent into an engineering-focused reference. It also distinguishes the MC145012P from generic smoke-detector transistors by documenting its complete photoelectric detection, I/O, and temporal horn-drive roles in one component.
Alternativas directas para MC145012P — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
No hay alternativas directas disponibles para este producto.
Solicitar alternativasMC145012P Especificaciones
| Product Type | Photoelectric smoke detector IC with I/O and temporal pattern horn driver |
| Manufacturer | NXP Semiconductors |
| Process Technology | CMOS |
| Operating Voltage Range | 6 V to 12 V |
| Average Supply Current | 8 µA |
| Detection Method | Infrared photoelectric light scattering |
| Input Type | Photoelectric input |
| Tipo de salida | Output for temporal-pattern horn driver |
| Interconnection Feature | I/O pin for unit interconnection |
| Encapsulado | 16-pin plastic dual in-line package |
| Package Type | 16-PDIP |
| Tipo de montaje | Through-hole |
| Number of Terminals | 16 |
| Design Compliance Target | UL217 and UL268 |
Guía de configuración de pines de MC145012P 16-pdip
Configuración de pines para MC145012P (encapsulado 16-pdip). La numeración de pines, las funciones y los diagramas de conexión se definen en la hoja de datos del fabricante. Consúltela para conocer el footprint exacto y las directrices de soldadura.
No hay datos detallados de patillaje disponibles para MC145012P.
Consulte la hoja de datos para ver la configuración completa de patillas.
Aplicaciones típicas
MC145012P es adecuado para 6 aplicacións: Residential Photoelectric Smoke Alarm, Interconnected Smoke-Alarm Network, Battery-Backup Alarm Module, Commercial Building Smoke Detector, Low-Power Aerosol Alarm, Self-Test Smoke-Detector Electronics.
Residential Photoelectric Smoke Alarm
The MC145012P fits a residential photoelectric alarm because it combines infrared chamber sensing, low-power control, alarm timing, and horn drive in one CMOS device. Its 6 V to 12 V operating range and 8 µA average supply current are well aligned with low-power alarm designs, helping limit standby energy consumption. The IC is normally connected to an external photoelectric chamber and supports detection when scattered infrared light indicates smoke particles or aerosols. The horn section then generates the temporal alarm pattern. A finished alarm still requires chamber calibration, battery-life testing, sound-level validation, and applicable safety certification.
Interconnected Smoke-Alarm Network
The MC145012P is appropriate for interconnected smoke alarms because its I/O pin provides a dedicated unit-interconnection function. Designers can combine photoelectric detection and temporal horn signaling within each alarm while coordinating multiple units across the installation. The 8 µA average supply current is valuable in battery-operated designs because standby energy influences service life. PCB implementation should follow the manufacturer reference circuit, keep the interconnection and horn-drive paths away from sensitive photoelectric inputs, and verify line behavior, alarm propagation, and fault conditions across the complete network.
Battery-Backup Alarm Module
The MC145012P can serve as the sensing and signaling controller in a battery-backup smoke-alarm module. Its stated 6 V to 12 V supply range supports common low-voltage alarm architectures, while its 8 µA average current limits baseline consumption. The actual battery budget must also include the infrared chamber, horn activation, external network components, leakage, and startup demand. Designers should evaluate the device across standby and alarm conditions, confirm the recommended supply bypass arrangement, and verify that horn transients do not disturb the low-level photoelectric measurement path.
Commercial Building Smoke Detector
The MC145012P can support photoelectric detector electronics used in commercial building alarm products. Integrating the sensing interface, I/O function, and temporal-pattern horn driver reduces the component count compared with a fully discrete implementation. Its 8 µA average supply current is favorable for low-power designs, although commercial systems may impose additional diagnostic, alarm, and interconnect requirements. Final selection should follow the NXP application schematic and include chamber behavior, environmental false-alarm testing, alarm audibility, and compatibility with the building's wiring topology.
Low-Power Aerosol Alarm
The MC145012P is suitable for a low-power aerosol alarm that uses infrared light scattering as its sensing principle. The chip's analog and digital circuitry detects scattered light from minute particles and activates a temporal horn pattern when the alarm condition is recognized. Its 6 V to 12 V supply range and 8 µA average current support compact, energy-conscious products. Engineers should select and align the external chamber carefully, establish the intended aerosol sensitivity, and validate threshold stability under temperature, humidity, and aging conditions before production use.
Self-Test Smoke-Detector Electronics
The MC145012P can form the functional core of a smoke-detector product that adds self-test or system monitoring around the sensing and horn-drive functions. The integrated photoelectric interface reduces the number of separate analog and timing blocks, while the I/O pin supports coordination with other alarm units. Because the manufacturer description does not define a dedicated self-test feature, the complete test strategy must be implemented and validated at the system level. Fault checks should not inject signals that exceed the device's stated operating limits, and horn activation should be accounted for in power and sound-pattern validation.
Datos de referencia de ingeniería para MC145012P — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Notas de diseño
Follow the NXP application schematic when placing the MC145012P and its photoelectric chamber interface. Keep the chamber-connected input route short and physically separated from horn-drive and switching-current paths to reduce noise coupling. Use a low-impedance ground plane or equivalent return arrangement, place required bypass capacitors close to their associated supply pins, and inspect the assembled board for contamination or solder flux around high-impedance sensing nodes.
Design the supply for the documented 6 V to 12 V operating range and calculate energy use across standby, startup, chamber operation, and horn alarm states. The 8 µA average supply current does not represent peak alarm demand, so battery and regulator sizing must include the external horn and associated circuitry. Verify startup behavior, supply tolerance, decoupling, and the voltage present at the IC during the most demanding alarm event.
Do not treat a generic 16-pin timer or alarm IC as a replacement for the MC145012P. A valid device must reproduce the photoelectric sensing interface, I/O behavior, temporal horn output, electrical limits, and exact 16-pin connections. Also confirm the chamber orientation and optical alignment: incorrect chamber geometry or board placement can change sensitivity and false-alarm behavior even when the electrical circuit is correct.
Preserve the documented relationship between the photoelectric chamber, sensor input, ground reference, and horn-driver output. Keep high-current horn paths physically separate from the sensitive analog section, use a common ground strategy that avoids large pulse-current voltage drops at the chip, and route supply and return conductors with low loop area. After assembly, validate detector sensitivity and horn activation together because either activity can reveal unintended coupling.
Información de cumplimiento
The manufacturer description states that the circuit is designed to operate in compliance with UL217 and UL268. These application-design references do not establish RoHS, REACH, lead-free, halogen-free, conflict-minerals, or AEC-Q100 status for the component.
