EVB7122

27 to 930MHz Transceiver

Evaluation Board Description

39012 07122 02

Page 5 of 24

EVB Description

Rev. 005

June/07

2

Description of User Modes

2.1

Stand-alone User Mode Operation

After power up the transceiver is set to stand-alone user mode. In this mode, pins FS0/SDEN and FS1/LD

must not be changed after power up in order to remain in stand-alone user mode. The default settings of the

control word bits in stand-alone user mode are described in the frequency selection table. Detailed

information about the default settings can be found in the tables of section 5.

2.1.1

Frequency Selection

Channel frequency

433.92 MHz

868.3 MHz

315 MHz

915 MHz

FS0/SDEN

1

0

1

0

FS1/LD

0

0

1

1

Reference oscillator frequency

7.1505 MHz

R counter ratio in RX mode (RR)

32

16

18

32

PFD frequency in RX mode

223.45 kHz

446.91 kHz

397.25 kHz

223.45 kHz

N counter ratio in RX mode (NR)

1894

1919

766

4047

VCO frequency in RX mode

423.22 MHz

857.60 MHz

304.30 MHz

904.30 MHz

RX frequency

433.92 MHz

868.30 MHz

315.00 MHz

915.00 MHz

R counter ratio in TX mode (RT)

32

16

18

32

PFD frequency in TX mode

223.45 kHz

446.91 kHz

397.25 kHz

223.45 kHz

N counter ratio in TX mode (NT)

1942

1943

793

4095

VCO frequency in TX mode

433.92 MHz

868.30 MHz

315.00 MHz

915.00 MHz

TX frequency

433.92 MHz

868.30 MHz

315.00 MHz

915.00 MHz

IF in RX mode

10.7 MHz

10.7 MHz

10.7 MHz

10.7 MHz

In stand-alone user mode, the transceiver can be set to Standby, Receive, Transmit or Idle mode (only PLL

synthesizer active) via control pins RE/SCLK and TE/SDTA. The modulation scheme and the LNA gain are

set by pins ASK/FSK and GAIN_LNA, respectively.

2.1.2

Operation Mode

Operation mode

Standby

Receive

Transmit

Idle

RE/SCLK

0

1

0

1

TE/SDTA

0

0

1

1

Note:

Pins with internal pull-down