3D Low Power Wake-up Receiver AS3931 1. General Description AS3931 is an ultra low power, three channel LF ASK receiver designed to operate in various applications such as LF identification systems and LF tag receivers. AS3931 is able to detect a low frequency ASKmodulated signal by looking for a digital wake-up pattern and generates a WAKE signal after successful pattern detection. The device incorporates an intelligent pattern detection algorithm that provides reliable operation even in presence of strong interferences. RSSI signals can be generated at the RSSI pin for each receiver channel. 2. Key Features - 3D wake-up pattern detection 3D LF field strength measurement Antenna rotation for easy calibration High sensitivity and high dynamic range Wide operating frequency range Reliable, interference resistant wake-up decoding Highly protected differential inputs Ultra low power consumption 3. Main characteristics - Wake-up sensitivity: 350 µVpp LF carrier frequency range: 19 – 150 kHz Data rate: 2.731 kb/s Current consumption in standby mode: 6.6 µA Dynamic range: 60 dB - RSSI step: (∆V RSSI @ 1 mVpp input amp.): 290 mV Revision No. 1.1, Date: 09-2005 PRODUCT BRIEF 4. Additional Features - Antenna rotation switch three independent LF receiver chains Wake-up output combining the three receiver chains Low power 32.768 kHz crystal oscillator circuit Serial programming interface Voltage regulator with 2.4 V output, on/off switchable Each independent LF receiver chain contains: - Input overload protection - Input attenuator - Ultra low power LF amplifier with logarithmic envelope output - Robust data detector with adaptive slicing threshold that translates the logarithmic envelope into a digital data signal - Error tolerant digital pattern correlator that detects a given code sequence in the received data signal and generates a wake-up signal Sophisticated power management logic that powers down the correlator if no data is received 5. Applications - LF identification systems LF tag receivers Three-dimensional LF field strength measurement systems Ultra low power wake-up systems Page 1 of 2 Copyright © 2005 austriamicrosystems. Trademarks registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. To the best of its knowledge, austriamicrosystems asserts that the information contained in this publication is accurate and correct. Product Brief AS3931 Input Protection 3 Input Attenuator 3 Detector 2 Data 1 Wake 1 WAKE Multiplexer LF2P LF2N Correlator 2 Wake 2 Log. Env. Amp 2 Correlator 1 Wake Log. Env. Amp 3 LF3P LF3N Detector 3 Correlator 3 Wake 3 Input Attenuator 2 Input Protection 2 Detector 1 Data 2 Log. Env. Amp 1 LF1P LF1N Data 3 Input Attenuator 1 RSSI 2 Antenna Rotator RSSI 3 Input Protection 1 RSSI 1 Block Diagram AS3931 wake generator CS SCL SDA RSSI Multiplexer Control Logic Multiplexer Data Multiplexer RSSI Buffer VCC Regulator Oscillator VREG RSSI POR XIN XOUT GND Package, Pin-out and Marking 16 pin TSSOP package 2 15 3 14 4 5 6 xxxxxxxx 16 AS3931 1 13 12 11 7 10 8 9 Revision No. 1.1, Date: 09-2005 1 VCC 2 LF1N 3 LF1P 4 LF2N 5 LF2P 6 LF3N 7 LF3P 8 GND xxxxxxxx = Date Code and 16 15 14 13 12 11 10 9 Plant ID VREG RSSI SDA SCL CS WAKE XOUT XIN Page 2 of 2 Copyright © 2005 austriamicrosystems. Trademarks registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. To the best of its knowledge, austriamicrosystems asserts that the information contained in this publication is accurate and correct.