AS3933 datasheet(18/64 Pages) AMSCO

18 / 64 page

ams Datasheet

Page 17

[v1-08] 2015-Sep-02

Document Feedback

AS3933 − Detailed Description

The AS3933 is a three-dimensional low power low-frequency

wake-up receiver. The AS3933 is capable of detecting the

presence of an inductive coupled carrier and can extract the

envelope of the ON-OFF-Keying (OOK) modulated carrier. In

case the carrier is Manchester coded, the clock can be recovered

from the received signal and the data can be correlated with a

programmed pattern. If the detected pattern corresponds to

the stored one, a wake-up signal (IRQ) is risen up. The pattern

correlation can be disabled; in this case the wake-up detection

is based only on the frequency detection.

The AS3933 is made up of three independent receiving

channels, one envelop detector, one data correlator, one

Manchester decoder, 19 programmable registers with the main

logic and a Clock Generator.

The digital logic can be accessed by an SPI. The Clock Generator

can be based on a crystal oscillator, or an internal RC-oscillator

or an external clock. In case the RC-oscillator is used to improve

its accuracy, a calibration can be performed.

The internal LC-oscillator can deliver the antenna’s oscillation

frequency for each channel and the internal tuning capacitor

bank can provide fine tuning.

The Internal RC-oscillator can be calibrated either over SPI or

using the internal algorithm based on the antenna resonance

frequency.

Figure 19:

Block Diagram of LF Wake-Up Receiver AS3933

Detailed Description

Wakeup

Main Logic

Envelope Detector /

Data Slicer

Correlator

I/ V

Bias

Xtal Oscillator

Xin

RC Oscillator

Manchester

Decoder

SPI

Channel

Amplifier 1

Channel

Amplifier 2

Channel

Amplifier 3

RSSI

Data

IRQ

Xout

GND

VCC

LF1P

LF2P

LF3P

SCL

SDI

SDO

LFN

DAT

CL_DAT

Channel

Selector

Freq. OK

Tuning

Capacitors

Tuning

Capacitors

Tuning

Capacitors

LC-Oscillator

Clock Buffer

Clock Generator

AS3933 Datasheet(PDF) 18 Page - ams AG

AS3933 Datasheet(HTML) 18 Page - ams AG

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

Datasheet Download

Link URL