DS12858 Rev 2

11/20

STA5635A

Antenna sensing

19

3

Antenna sensing

The Figure 5 shows how antenna sensing circuit works with 3.3 V Antenna.

Figure 5. Antenna sensing configuration

In the output two bit in 1V1 domain are delivered to SPI and interrupt logic.

In the following tables are showed thresholds when current is rising and when is falling with

R=1.4 Ω and V_ant=3.3 V.

Table 3. Thresholds when current is rising

Current from antenna

(when current is rising)

SENSE<1>

SENSE<0>

I < 24 mA

0

0

24 ≤ I ≤ 62 mA

0

1

I > 62 mA

1

1

Table 4. Thresholds when current is falling

Current sunk from antenna (when

current is falling)

SENSE<1>

SENSE<0>

I > 53 mA

1

1

16 ≤ I ≤ 53 mA

0

1

I < 16 mA

0

0