Rev. 3.5

RI-RFM-006A

Page 13 of 19

! Applied Circuit Configuration - Example

Shown below is an example of applied circuit configuration for constructing a TIRIS Transmit-Receive

RF-module using the RI-RFM-006A. This example illustrates a simplified amplifier circuit for received

signals by eliminating a frequency band rejection filter which effectively eliminates external noises and

signals out of the frequency band of the response signals from the remote TIRIS transponder. In this

configuration, therefore, it is assumed that the available data communication distance of the system could

be easily affected by environmental conditions.

Note that this is only one of various possible applications. For more information of applied circuit

configurations, refer to the Application Handbook issued by our TIRIS Operation Dept.

* When configuring an applied circuit, take the following into account:

• Choose the capacity of a resonance capacitor for clock generator oscillator in accordance with the

oscillator characteristics.

• Define the frequency accuracy and variation of the clock generator oscillator by conversion based on

the specifications for the TIRIS transponder to be used together so that it can be within the range of

17.17248 MHz to 17.18272 MHz (standard frequency: 17.1776 MHz).

• Select the values at resonance points around 134.2 kHz for L and C of the antenna circuit,

respectively. (In the example illustrated above, the following combination is used: antenna: 48

µH;

capacitor: 0.03

µF = 0.01 µF x 3 units)

• It is desirable to use a MOSFET having a low on-state resistance for antenna driver

TMS57780NS

9

10

11

12

13

14

15

16

5

1234

678

ANTENNA

VCC

GND

TXCT

RXDT

RXCK

NC

1M

1200pF

68pF

68pF

68pF

0.01uF 0.01uF 0.01uF

120pF

120pF

1M

10K

100

1S1588

1S1588

120

100uF

0.1uF

17.1776MHz

(*)

(*)

2SJ182

2SK974

(L=48uH)

RI45538NS