Elmos introduces ultra-low power pyroelectric sensor technology solutions

Single chip microcomputer STM32L151CCU6

Shunluo Inductance Power Inductor SWPA Series First Class Agent

Dortmund, Germany, Al Summers Company (elmos) has announced an ultra-low power consumption for human passive infrared (PIR) application solutions E931.96. The solution passes pyroelectric infrared Sensor The signal radiated by the human body is detected in a non-contact manner, and the signal is converted into an electrical signal and input into the chip for signal processing. The chip's low operating current, typical power consumption is only 3μA, making it ideal for power-hungry applications and battery-powered applications.

E931.96 is an ultra-low power programmable PIR control chip, especially suitable for wireless security alarms, demanding power supply and other requirements. Use the sensor The low power consumption feature, when the alarm signal is detected, wakes up the microcontroller from sleep mode, and then sends a radio frequency signal for remote wireless alarm.

First, when the system is powered up, the external MCU should be configured with E931.96 , and the necessary configuration parameters should be written into the E931.96 internal register. Then, it enters the normal working mode according to the written information and discriminating basis. Once in this mode, the system will enter the monitoring arming mode and initiate an alarm program if there is an illegal intrusion. In this process, the system consumes only very low current. Pyroelectric sensor during arming And the chip of E931.96 is in normal working mode. In the case of no illegal intrusion, in order to reduce the operating current of the system, the MCU can be put to sleep, and only when E931.96 detects illegal intrusion. Wake up the microcontroller system. Through this way of working, the battery life and endurance can be greatly increased.

In addition, the chip can be configured by an external microcontroller, which can use the internal ADC of E931.96 to detect its own temperature and power supply voltage. In addition, a Zener is integrated inside the chip, and this Zener can also be set by software to external circuits (such as analog PIR sensors). ) Provide a stable power supply.

In order to increase the range of viewing angles, in practice, two analog probes can be connected in parallel to the input port of the E931.96 to monitor a larger area.

At present, E931.96 mainly provides SO8 package form, and has been supplied to customers in batches.

Figure 1. Block diagram of the internal structure of E931.96

Figure 1 above is the internal block diagram of the chip. PIRIN and NPIRIN on the left are the two signal input ports of the chip, PIR sensor. The detected human body signal is converted into a voltage signal and transmitted to the E931.96 through these two pins. After the signal enters the chip, it is converted by AD, and the subsequent signal processing and sensing output are performed according to the user-configured operating mode. On the right side of the block diagram, the power interface VDD and VSS ground. The working mode of the chip is single-wire communication through the SERIN port and the external MCU, and the configured parameters are written into the chip. During operation, the INT/DOCI interface operates according to the set mode and outputs corresponding sensing signals to the outside.

main feature

3μA ultra low operating current

Programmable monitoring mode

On-chip integrated temperature and voltage detection

Optional on-chip voltage regulator for stable power supply to external loads such as analog PIR probes

Strong anti-radio interference capability

Single line parameter configuration, single line induction alarm output

Application field

High battery life and wireless human body detection sensor application

Pyroelectric human detection and security alarm

Pyroelectric body sensor light controller

Typical application circuit

Figure 2. Typical application circuit for E931.96

Figure 2 above is a typical application circuit that combines a traditional analog probe. Pyroelectric sensor After identifying the signal of the human body movement, pass it to E931.96, then E931.96 works according to the working mode of the external MCU configuration (configured by the SERIN pin), and the processed signal is processed and passed to or Wake up the external microcontroller. In this application, we also see that the power supply of the analog probe is provided by the internal voltage regulator of E931.96, which can save external external power supply loop and reduce system cost.

For more information, data sheets, application notes, and for samples and reference designs, please send the theme "Smart Building" e-mail to sales_china @ elmos .com, visit the company's Web site (www. Elmos .com).