A5358CA-T

• Product Introduction

The A5358 is a low-current BiCMOS circuit that provides all the features needed for a photoelectric smoke detector. The device can be used in conjunction with an infrared photochamber to sense light emitted by smoke particles. The networking feature allows up to 50 devices to be interconnected, and all devices can sound an audible alarm when any device detects smoke. Special features are also integrated into the design to facilitate calibration and testing of the finished detector. The device is designed for use in applications that comply with European Standard EN 14604 and British Standard BS 5446 Part 1.

The variable gain optical amplifier interacts directly with the IR emitter-detector pair. The amplifier gain level is determined by two external capacitors and is selected internally based on the operating mode. Select Low Gain in Standby and Timer modes. When a local alarm occurs, the low gain will be increased (internally) by about 10% to reduce false triggering. High gain is used when the light chamber sensitivity is regularly monitored during key tests or standby mode.

The built-in oscillator and timing circuitry senses smoke for only 100 milliseconds every 10 seconds, dramatically reducing standby power consumption. In addition, a special third-order acceleration sensing scheme is integrated to shorten the time it takes to issue an audible alarm while reducing false triggering. The light chamber sensitivity is monitored regularly, and an alarm signal (chirp) will be issued when there are two consecutive cycles of sensitivity drops.

• 低平均待机电流，延长电池寿命
• 互连超过 50 台探测器
• 压电告警驱动器
• 低电量探测（均为内部）
• 光室灵敏度测试和告警
• 通电重置 (POR)
• 低灵敏度模式的内部计时器和控制
• 降低错误触发的内置电路
• 6 至 12 伏特工作范围
• 所有引脚均有 ESD 保护电路