AS3911 datasheet(137/149 Pages) AMSCO

137 / 149 page

ams Datasheet, Confidential: 2013-Oct [2-03]

AS3911 – 137

Appl icatio n I n f o rm a t i o n

Figure 123:

Connection of Tuning Capacitors to the Antenna LC Tank in case of Single (left) and Differential

Driving (right)

Antenna Tuning Using ‘Antenna Calibration Control’ Register

There is also a possibility to control the position of the TRIM

switches by writing the Antenna Calibration Control Register.

When the bit trim_s of this register is set to 1 position of the

trim switches is controlled by bits tre_3 to tre_0.

Using this register and performing phase and amplitude

measurements (using direct commands Measure Phase and

Measure Amplitude) different tuning algorithms can be

implemented in the external controller.

Stream Mode and Transparent Mode

Standard and custom 13.56 MHz RFID reader protocols, which

are not supported by the AS3911 framing, can be realized using

the AS3911 AFE and framing implemented in the external

microcontroller.

Transparent Mode

After sending the direct command Transparent Mode the

external microcontroller directly controls the transmission

modulator and gets the Receiver output (control logic becomes

“transparent”).

TRIM1_0

TRIM1_1

TRIM1_2

TRIM1_3

RF01

RF02

RFI1

RFI2

Antenna

TRIM2_3

TRIM2_2

TRIM2_1

TRIM2_0

TRIM1_0

TRIM1_1

TRIM1_2

TRIM1_3

RF01

RF02

RFI1

RFI2

½ Antenna

TRIM2_3

TRIM2_2

TRIM2_1

TRIM2_0

AS3911 Datasheet(PDF) 137 Page - ams AG

AS3911 Datasheet(HTML) 137 Page - ams AG

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL