ATR4258 datasheet(18/38 Pages) ATMEL

18 / 38 page

ATR4258

4838A–AUDR–10/04

Adjacent Channel

Sensor

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

outside the reception band.

Figure 8. Adjacent Channel Sensor

MPINT and ADJAC Reset

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

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

discharged very quickly.

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 repre-

sented 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 9. Multipath Sensor

Pin 10 (ADJAC)

SMeter

30 µA

Pin 9 (Meter)

Table 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