P2001

ETALDOC 100/17

Page 3 of 5

February 2006

PERFORMANCE CHARACTERISTICS

-14

-22

-26

-30

100Hz

200 300

500

Typic al

Worst Ca se

1kHz

2

Frequency

dB

34 5

10

-18

Return Loss

Fig 4

0

-0.2

-0.3

-0.4

100Hz

200 300

500

1kHz

2

Frequency

dB

34 5

10

-0.1

Typ

ic a

l

Wo

rst

Ca

se

Frequency Response

Fig 3

Recommended Circ uit

Fig 2

560

LINE

600

* If return loss > 16dB, 300Hz - 4kHz is a c ceptab le, bloc king

ca pa citor ma y b e relaxed to 4.7 F

µ

33nF

27nF

5%

+_

2%

+_

*

+50%

20%

_

µ

6.8 F

+50%

20%

_

5%

+_

600

MATCH

Ω

EUROPEAN CTR21 COMPLEX MATCH

Figure 5 gives flat RX and TX responses against the

reference impedance (typically around

0.5dB

300Hz - 3.4kHz). Return loss is typically better than

20dB.

The circuit values in parentheses give

optimum flatness at a small sacrifice in return loss.

For circuits with existing board drillings, figure 6

gives good return loss (>20dB) and RX flatness

against the reference impedance, but TX flatness is

degraded by the use of this topology.

+

_

Recommended Circ uit

Fig 5

150

(220)

LINE

270

750

750

(680)

56nF

(150nF)

100nF

150nF

µ

2.2 F

Recommended Circ uit

Fig 6

820

LINE

270

750

330

27nF

68nF

150nF

µ

2.2 F