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AS3930

Datasheet - Detailed Descr i p ti on

8 Detailed Description

The AS3930 is a one-dimensional low power low-frequency wake-up receiver. The AS3930 is capable of detecting the presence of an inductive

coupled carrier and extract the envelope of the On-Off-Keying (OOK) modulated carrier. In case the carrier is Manchester coded, then the clock

is recovered from the transmitted signal and the data can be correlated with a programmed pattern. If the detected pattern corresponds to the

stored one, then a wake-up signal (IRQ) is risen up. The pattern correlation can be bypassed in which case the wake-up detection is based only

on the frequency detection.

The AS3930 is made up of a single receiving channel, one envelop detector, one data correlator, 8 programmable registers with the main logic

and a real time clock.

The digital logic can be accessed by an SDI. The real time clock can be based on a crystal oscillator or on an internal RC. If the internal RC

oscillator is used, a calibration procedure can be performed to improve its accuracy.

Figure 10. Block Diagram of the LF Wake-up Receiver AS3930

LF1P

LFN

GND

XIN

XOUT

DAT

CS

SDO

SDI

SCL

IRQ

RSSI

Wakeup

AS3930, 1-D LF Wakeup Receiver

SDI

Main

Logic

Envelope Detector / Data Slicer

Correlator

Channel

Amplifier1

I/V

Bias

Xtal RTC

RC RTC