ATR4258 datasheet(18/38 Pages) ATMEL

18 / 38 page

4838B–AUDR–05/05

ATR4258

4.24

Adjacent Channel Sensor

The adjacent channel sensor is active in FM mode only and measures the field strength outside

the reception band.

Figure 4-6.

Adjacent Channel Sensor

4.25

MPINT and ADJAC Reset

Bit 6 allows a resets of the multipath sensor and the adjacent channel sensor by connecting

pin 10 and pin 40 internally to ground and so the external capacitors can be discharged very

quickly.

4.26

Multipath Sensor

The multipath sensor is active in FM mode only and measures the disturbance due to multipath

reception. The multipath sensor detects drops in the field strength after the integrated band filter

by calculating the difference between an averaged maximum field strength and the current field

strength. The maximum depth of these drops is represented by the voltage of the peak detector

at pin 40 (MULTIP). The level of this voltage represents the degree of disturbance in the

received signal.

Figure 4-7.

Multipath Sensor

Pin 10 (ADJAC)

SMeter

30 µA

Pin 9 (Meter)

Table 4-30.

Multipath and Adjacent Channel Reset

MPINT and Adjacent Channel (Pin 10 and Pin 40)

Bit 6

Normal mode

Connection to ground

Pin 40

ATR4258 Datasheet(PDF) 18 Page - ATMEL Corporation