Wake up and hear the IR
receiving infrared (ir) signals while conserving system power is difficult, and typically requires the inclusion of complex power-management routines in the firmware. you can avoid that problem by disconnecting power to the microcontroller when ir is not present. the resulting circuit draws less than 2µa of supply current while in standby mode, and approximately 40µa when active.
a similar version of this article appeared online in the october 10, 2006 issue of ee times.
receiving infrared (ir) signals while conserving system power is difficult, and typically requires the inclusion of complex power-management routines in the firmware. you can avoid that problem by disconnecting power to the microcontroller when ir is not present (figure 1). u1 holds the attached microcontroller in an ultra-low power-down state until the phototransistor (q1) detects an ir signal.
figure 1. this circuit withholds power from the attached microcontroller until it detects an ir transmission. while in standby mode, its quiescent current is less than 2µa.
upon detecting an ir signal and after a suitable delay (300ms in this case), the circuit connects power to the microcontroller and applies a reset signal to it (figure 2). after power-up, the microcontroller must assert its hold line to prevent the circuit from returning to standby mode when the ir transmission ends. u2 buffers and inverts the ir transmissions. when the microcontroller has completed its tasks and no more ir transmissions are present, it returns the circuit to standby mode by deasserting the hold line.
figure 2. when the figure 1 circuit detects an ir signal, it powers and resets the microcontroller. after the ir transmission ends, the microcontroller suspends itself by releasing the hold line.
the circuit draws less than 2µa of supply current while in standby mode, and approximately 40µa when active. the combined battery monitor and microprocessor supervisor (max6848k) comes in several versions, offering multiple voltage thresholds for the microcontroller power, and multiple reset delays. thus, you should choose the part-number option according to your application. the maximum data rate (determined by q1) exceeds 10kbps.
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a similar version of this article appeared online in the october 10, 2006 issue of ee times.
receiving infrared (ir) signals while conserving system power is difficult, and typically requires the inclusion of complex power-management routines in the firmware. you can avoid that problem by disconnecting power to the microcontroller when ir is not present (figure 1). u1 holds the attached microcontroller in an ultra-low power-down state until the phototransistor (q1) detects an ir signal.
figure 1. this circuit withholds power from the attached microcontroller until it detects an ir transmission. while in standby mode, its quiescent current is less than 2µa.
upon detecting an ir signal and after a suitable delay (300ms in this case), the circuit connects power to the microcontroller and applies a reset signal to it (figure 2). after power-up, the microcontroller must assert its hold line to prevent the circuit from returning to standby mode when the ir transmission ends. u2 buffers and inverts the ir transmissions. when the microcontroller has completed its tasks and no more ir transmissions are present, it returns the circuit to standby mode by deasserting the hold line.
figure 2. when the figure 1 circuit detects an ir signal, it powers and resets the microcontroller. after the ir transmission ends, the microcontroller suspends itself by releasing the hold line.
the circuit draws less than 2µa of supply current while in standby mode, and approximately 40µa when active. the combined battery monitor and microprocessor supervisor (max6848k) comes in several versions, offering multiple voltage thresholds for the microcontroller power, and multiple reset delays. thus, you should choose the part-number option according to your application. the maximum data rate (determined by q1) exceeds 10kbps.
苹果新消息称，iPhone12或迎来了新的技术突破
芯天下针对性地研发了“Wide Voltage SPI NOR存储器”产品，以迎接即将到来的物联网时代！
如何选择数字晶体管
阿里云王牌架构师一问开发者：我需要一个高并发的架构，系统要改造成微服务吗
监听系统的校准
Wake up and hear the IR
无人机汽车首次成功完成的高空试飞
我国将大力发展风电、光伏发电等发展
具有高性能处理器且价格更具竞争力的新型OnePlus 9 Lite
各有所长的总线驱控谁能最终称霸运控市场
关于自动驾驶视觉芯片的DNN之争
配电箱的规格尺寸 配电箱的固定方式
单片机实用框架-1
华硕展出一台新款的ZenScreen Go可移动显示屏，自带电池及支持触控
什么是差模噪声和共模噪声，它们之间有什么区别
华为P10正在遭遇当年华为Mate8之痛
现代汽车将在CES 2020活动上发布城市空中移动出行计划
嵌入式计算机如何助力偏远地区的安防建设
铃木新型Hustler发布，ADAS和导航系统都有改进
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