XE1203F Ver la hoja de datos (PDF) - Semtech Corporation

Número de pieza

componentes Descripción

Fabricante

XE1203F

433 MHz / 868 MHz / 915 MHz Low-Power, Integrated UHF Transceiver

Semtech Corporation 

XE1203F

6 APPLICATION INFORMATION

This section provides details of the recommended component values for the frequency dependant blocks of the

XE1203F. Note that these values are dependent upon circuit layout and PCB structure, and that decoupling

components have been omitted for clarity.

6.1 RECEIVER MATCHING NETWORK

The schematic of the matching network at the input of the receiver is given below in Figure 19 (for a source

impedance of 50Ω).

SOURCE

CR3

CR1

LR1

CR2

RFA

XE1203

RFB

Figure 19: Receiver matching network

The typical recommended values for the external components are shown in Table 21:

Name

CR1

CR2

CR3

LR1

Typical Value

for 434 MHz

1.5 pF

1.5 pF

NC

100 nH

Typical Value

for 868 MHz

1.5 pF

1.2 pF

NC

27 nH

Typical Value

for 915 MHz

1.0 pF

1.0 pF

NC

27 nH

Tolerance

± 5%

± 5%

± 5%

±5%

Table 21: Typical component values for the matching network

6.2 TRANSMITTER MATCHING NETWORK

The optimum load impedances for 15 dBm output power at the three main frequencies are shown in Table 22:

PA optimum load

434 MHz

102 – 12j

868 MHz

78 + 19j

915 MHz

83 + 18j

Table 22: Optimum load impedances for 15 dBm output power

The Smith charts in Figure 20, Figure 21, and Figure 22 below show contours of output power versus load

impedance when the highest transmit level is selected, i.e. 15 dBm:

© Semtech 2007

www.semtech.com

31

Share Link: