AS3931 View Datasheet(PDF) - austriamicrosystems AG

Part Name

Description

Manufacturer

AS3931

3D Low Power Wakeup Receiver

austriamicrosystems AG 

AS3931

Datasheet - Detailed Description

8 Detailed Description

8.1 Block Diagram

Figure 13. Block Diagram

LF1P

lid LF1N

a LF2P

LF2N

ill v LF3P

LF3N

Input

Protection1

Antenna Rota-

tor

Input

Attenuator1

Input

Protection2

Input

Attenuator2

Input

Protection3

Input

Attenuator3

Log. Env. Amp 1

Log. Env. Amp 2

Log. Env. Amp 3

G st CS

SCL

Control Logic

A t SDA

Detector1

Detector2

Detector3

RSSI

Multiplexer

s n VCC

Regulator

Regulator

POR

Correlator1

AS3931

Correlator2

Correlator3

Wake

Wake Generator

Data

Multiplexer

RSSI

Buffer

am onte 8.2 Block Description

c 8.2.1 Antenna Rotator

l In order to achieve an optimum assignment of the antennas to the receiving channels, the connection of the antennas to the channels can be

changed cyclically with a multiplexed (antenna rotator), which is controlled by an internal register. The register setting can be changed by the

a serial interface.

ic 8.2.2 Input Attenuator

Input signal attenuation is provided for each channel by means of connecting a 1.5 kΩ resistor across the differential inputs. An internal register

controls attenuation.

n 8.2.3 Input Shortcutting

h The differential inputs can be shortened by register settings to measure the RSSI offset. In this case, the resistance between the differential

inputs is reduced to approximately 500 Ω.

c 8.2.4 Input Protection Circuit

e Each signal input has a powerful input overload protection circuit consisting of two anti-parallel protection diodes connected to ground (see

TFigure 14). This connection ensures that the differential input voltage can never exceed the supply voltage of the chip. To obtain proper

operation, the differential input receiving circuits (resonant RLC-circuits) must be floating and shall be grounded nowhere (see Figure 1)

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Revision 6.2

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