P3181 ETAL, P3181 Datasheet - Page 3

• Manufacturer Part Number: P3181
• Description: Line Matching Transformer
• Manufacturer: ETAL

Specifications of P3181

• Current Rating: 100µA
• Transformer Mounting: PC Board
• Length/height, External: 7mm
• External Width: 9mm
• External Depth: 13mm
• Transformer Type: Line Matching
• Mounting Type: SMD
• Primary Impedance: 600ohm
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Note - Fig. 2:
Typical distortion: excite from line at 150Hz to yield -10dBm @ 150Hz at line terminals.
Typical THD at line terminals will then be -90dBm (i.e. -80dBc).
For signals received from the line, the signal level present between terminals 1 and 3 of the transformer will be
approximately 6dB below the signal sustained at the line terminals.
Note - Figs. 2 and 3:
As line side components (22µF, 27nF) are common to both 600Ω and complex matches, switching between
matches can be performed solely on equipment side.
When driven from a balanced (differential) TX drive with unbalanced (single-ended) high impedance recever,
the following modifications can assist in giving good transhybrid loss (typically better than 18 dB across
voiceband):
* If components on line side to be unchanged for 600Ω/CTR21, compromise on 22nF.
† 4.7nF can also be fitted on 600Ω circuit with only minor degradation.
600 MATCH AND DISTORTION TEST CIRCUIT
As P3181 transformer has a non-unity turns ratio, orientation in circuit should be observed
ETALDOC 567/12
MATCHING RECOMMENDATIONS
600Ω
Fig. 4
Recommended Circuit
Fig. 2
600
Ω
600
LINE
LINE
15nF *
22µF
22µF
27nF
4
6
P3181
1.0:1.1
6
4
1.0:1.1
P3181
1
3
3
1
2.2k
10k
27nF
360
15nF
390
Note - Figs. 2, 3, 4 and 5:
TX
TXA1
TXA2
RXA
Page 3 of 5
Patented
EUROPEAN CTR21 COMPLEX MATCH
Recommended Circuit
Fig. 3
CTR21
Fig. 5
270
270
LINE
150nF
750
LINE
150nF
750
27nF
22µF
27nF
22µF
*
4
6
P3181
1.0:1.1
6
4
1.0:1.1
P3181
1
3
1
3
10k
2.2k
P3181
82nF
1k
82nF
1k
4.7nF
June 2006
†
TX
TXA1
TXA2
RXA