ETALDOC 591/9

Page 1 of 6

December 2003

PRODUCT DATA SHEET

LOW DISTORTION 

P3356

LINE MATCHING TRANSFORMER

Features

Applications

∗

 Lead-free (Pb-free)

∗

  V.90 and V.92 Modems

∗

 Low Distortion

∗

 V.34 Modems

∗

  12.6mm (0.5”) Seated Height

∗

 Fax Machines

∗

 Industry Standard Pinout

∗

 Instrumentation

∗

  IEC 950 and UL 60950 Certified

∗

  UL Recognized Component

∗

  Environmentally tested to IEC 68

∗

  CERT reliability tested

∗

  Excellent Frequency Response

∗

 Simple Matching

∗

  High Thermal Stability

 

 

DESCRIPTION

 

P3356 is intended for V.90 and V.92 (56kbps)

modems and other high-speed applications where
ultra-low distortion at moderate power levels and
very low voiceband frequencies is required at a
most competitive price.

P3356 uses patented design and construction
methods to achieve excellent signal performance
and safety isolation to international standards,
making it the component of choice for high-speed
data applications throughout the world.  P3356 is
certified to IEC 950, UL 60950. P3356 is a UL
Recognized Component, and is supported an
IEC CB Test Certificate. The part is completely
lead-free and suitable for lead-free and
conventional processing.

P3356 has exceptionally flat frequency response
from 30Hz to 10kHz, a 3dB bandwidth of over
50kHz and requires only the very simplest of
matching to achieve good return loss and
transhybrid loss across the voiceband, with very
low levels of signal distortion at signal frequencies
as low as 150Hz.

P3356 is a rugged lightweight design that
exhibits stable characteristics over its full
operating temperature range to maximize data
throughput under varying environmental
conditions without the need for modem
retraining.

P3356 has been subjected to relevant
environmental testing according to IEC 68 and
Combined Environmental Reliability Testing
(CERT) beyond normal operational levels and
passed all tests, remaining fully functional.

Patented

P3356

ETALDOC 591/9

Page 2 of 6

December 2003

SPECIFICATIONS

Electrical

At T = 25ºC and as circuit Fig. 2 unless otherwise stated.

Parameter

Conditions

Min

Typ

Max

Units

Insertion Loss

f = 2kHz, R

L

 = 600

Ω

-

1.5

-

dB

Frequency Response

LF -3dB cutoff
HF -3dB cutoff
100Hz – 4kHz

-
-
-

10
55

-

-
-

±

0.1

Hz

kHz

dB

Return Loss

(5)

200Hz – 4kHz

16

-

-

dB

Transhybrid Loss

(5)

200Hz – 4kHz

20

-

-

dB

Third Harmonic
Distortion

(1)

150Hz -3dBm in line
200Hz -10dBm in line

-
-

-70
-89

-
-

dBm
dBm

Voltage Isolation

(2)

50Hz
DC

2.12

3.0

-
-

-
-

kVrms

kV

Operating Range:
Functional
Storage

0

-40

-
-

+70
+85

ºC
ºC

Lumped equivalent circuit parameters as Fig. 1

DC resistance 

(3)

Primary resistance R

DCp

Secondary resistance R

DCs

70
95

-
-

87

120

Ω

Ω

Leakage inductance, 

∆

L

3

3.9

5

mH

Shunt inductance, Lp

(4)

200Hz, 10mV

6

9

-

H

Shunt loss, Rp

200Hz, 10mV

12

15

-

k

Ω

Notes:

1. Third harmonic typically exceeds other

harmonics by 10dB.

2.  Components are 100% tested at 3.25kVDC.
3.  Caution:   do not pass DC through windings.

Telephone line current must be diverted using
semiconductor line hold circuit or choke.

4.  At signal levels greater than 100mV, Lp will

increase and Rp will decrease slightly but the
effect is usually favourable to the return loss
characteristic.

5.  Return loss and transhybrid loss can be

improved to 30dB in improved matching circuit.
The values shown relate to the simplest
configuration, Fig. 2.

Equivalent Circuit

Fig. 1

IDEAL

1:1

½   L

½   L

P3356

ETALDOC 591/9

Page 3 of 6

December 2003

MATCHING RECOMMENDATIONS

The following recommendations start with the simplest implementations and progress to enhanced
performance utilizing additional components.   Good performance is achieved even with the simplest
configurations.  The implementations assume a low impedance balanced TX drive and a relatively high
impedance RX input, as is commonly available, though use with other TX/RX arrangements is
straightforward.   Note that there are no changes to components on the line side, or in the hybrid, whether
600

Ω

 or complex reference impedance selected, thus assisting country configuration. For complex

impedance, the matching circuits derived are suitable for reference impedances of the type 270 + 750//150nF
e.g. European CTR21 and 220 + 820//120nF (or 115nF) e.g. Australia, South Africa, etc., and yield similar
performance characteristics.   For other impedances, please contact Profec Technologies.

Minimum Cost Implementations

Insertion Loss:  1.8dB @ 2kHz
Frequency Response : ±0.2dB 30Hz – 10kHz
Return Loss:  16dB 200Hz – 4kHz
Transhybrid Loss:  22dB 200Hz – 4kHz

Insertion Loss:  1.0dB @ 2kHz
Frequency Response : ±0.5dB 50Hz – 4kHz
Return Loss:  18dB 200Hz – 4kHz
Transhybrid Loss:  14dB 200Hz – 4kHz

Improved matching

Insertion Loss:  1.8dB @ 2kHz
Frequency Response : ±0.2dB 30Hz – 10kHz
Return Loss:  18dB 200Hz – 4kHz
Transhybrid Loss:  22dB 50Hz – 10kHz

Insertion Loss:  1.0dB @ 2kHz
Frequency Response : ±0.5dB 50Hz – 4kHz
Return Loss:  20dB 200Hz – 4kHz
Transhybrid Loss:  16dB 50Hz – 4kHz

600

Ω

Fig. 4

LINE

600

10nF

560

RXA

TXA2

TXA1

µ

22 F

600

Ω

Fig. 2

LINE

600

560

RXA

TXA2

TXA1

µ

22 F

10nF

LINE

270

(220)

750

(820)

µ

22 F

150nF

(120nF)

750

100nF*

*Note:  100nF capacitor should have a temperature stable dielectric

120

European CTR21/(Australia, etc.)

Fig. 5

RXA

TXA2

TXA1

LINE

270

(220)

750

(820)

150nF

(120nF)

820

100nF*

*Note:  100nF capacitor should have a temperature stable dielectric

100

European CTR21/(Australia, etc.)

Fig. 3

RXA

TXA2

TXA1

µ

22 F

Patented

P3356

ETALDOC 591/9

Page 4 of 6

December 2003

Improved matching and hybrid

Insertion Loss (Line to RXA):  2.8dB @ 2kHz
Frequency Response : ±0.2dB 30Hz – 10kHz
Return Loss:  20dB 200Hz – 4kHz
Transhybrid Loss:  30dB 50Hz – 10kHz

Insertion Loss (Line to RXA):  2.2dB @ 2kHz
Frequency Response : ±0.5dB 50Hz – 4kHz
Return Loss:  20dB 200Hz – 4kHz
Transhybrid Loss:  18dB 200Hz – 4kHz

600

Ω

Ω

Ω

Ω

 Instrumentation

CERTIFICATION

Insertion Loss:  1.5dB @ 2kHz
Frequency Response : ±0.2dB 20Hz – 20kHz
Return Loss:  16dB 20Hz – 20kHz

SAFETY

Constructed in accordance with IEC 

60950-1,

EN 

60950-1, and UL 

60950-1, supplementary

insulation, 250Vrms maximum working voltage,
flammability class V-0.

There are no special installation requirements
(beyond attending to usual PCB track separations)
since the integral cover provides supplementary
insulation from its external faces to internal core
and windings.

Certified under the IEC CB scheme (Certificate
GB445W) to IEC 950:1991, up to amendment 4,
sub-clauses 1.5, 1.5.1, 1.5.3, 2.2, 2.2.3, 2.2.4, 2.9.2,
2.9.3, 2.9.4, 4.4, 4.4.3.2 (class V-0) and 5.3 for a
maximum working voltage of 250Vrms, nominal
mains supply voltage not exceeding 300Vrms
and a maximum operating temperature of 70ºC
in Pollution Degree 2 environments.

Recognized under the Component Recognition
Program of Underwriters Laboratories Inc. to US and
Canadian requirements CAN/CSA C22.2
No. 60950-1-03/UL60950-1, First Edition, based on
IEC 

60950-1, First Edition, maximum working

voltage 180Vrms (creepage), 420V peak
(clearance), Pollution Degree 2, supplementary
insulation.

UL File number E203175.

Additionally, Profec Technologies certifies all
transformers as providing voltage isolation of
2.12kVrms, 3kV DC minimum.  All shipments are
supported by a certificate of conformity to current
applicable safety standards.

600

Ω

Fig. 6

LINE

600

10nF

560

1k

1nF

10k

RXA

TXA2

TXA1

µ

22 F

10nF

1nF

LINE

270

(220)

750

(820)

µ

22 F

150nF

(120nF)

750

100nF*

*Note:  100nF capacitor should have a temperature stable dielectric

120

European CTR21/(Australia, etc.)

Fig. 7

RXA

TXA2

TXA1

1k

10k

µ

µ

47 F*

µ

47 F*

600   

Ω

Fig. 8

600

Ω

600

Ω

6.8nF

6.8nF

* If no DC block required, one of these capacitors can be removed and

 the other set to 22 F, or, if preferred, both capacitors can be eliminated.

Patented

P3356

ETALDOC 591/9

Page 5 of 6

December 2003

ENVIRONMENTAL TESTING

Reliability testing to IEC 68

Tested to clauses of IEC 68 and compliant with all functional and safety requirements following exposure as follows:

Test description IEC 68 reference

Test details

Result

Robustness of
terminations

68-2-21 Test Ua

1

68-2-21 Test Ua

2

Tensile 5N pull
Thrust 1N push

No impairment
No pin detachment or distortion

Solderability

68-2-20 Test Ta Method 1

Solder bath 235ºC 2s

Resistance to
soldering heat

68-2-20 Test Tb Method 1A
68-2-20 Test Tb Method 2

Solder bath 260ºC 10s
Soldering iron 350ºC 5s

No impairment
Finish smooth, bright and even

Vibration

68-2-6 Test Fc

Sweep 10-55-10Hz in 1 minute
Amplitude 1.5mm pk-pk
Duration 2h per axis, 3 axes

No impairment

Shock

68-2-27 Test Ea

Peak acceleration 1000m/s

2

Duration of pulse 6ms
3 shocks each direction on 3 axes

No impairment

Cold

68-2-1 Test Ab

-25ºC 16h
Recovery to ambient 1-2h

No impairment

Dry heat

68-2-2 Test Bb

125ºC 16h
Recovery to ambient 1-2h

No impairment

Damp heat

68-2-3 Test Ca

40ºC 4 days, RH 93%
Recovery to ambient 1-2h

No impairment

Change of
temperature

68-2-14 Test Na

T

A

 –25ºC

T

B

 +85ºC

t

1

 30 min

2 min 

≤

t

2

≤

3 min

Recovery to ambient 1-2h
5 cycles

No impairment

Combined Environmental Reliability Testing (CERT)

Components step stressed at increasing levels of severity using combined stresses to detect potential
weaknesses.
Results are shown for highest levels of stress tested. Compliant with all functional and safety tests following
exposure as follows:

Test description

Test details

Duration

Result

Storage Test

Thermal cycling -30ºC to +100ºC at
11ºC/min
6mm pk 2-9Hz at 1 octave/min
20m/s

2

 9-200Hz

20 mins per
plane

No impairment

Transportation Test

Thermal cycling -65ºC to +80ºC
Random vibration 10-200Hz and
200-2000Hz at 57m/s

2

 RMS

2 hours per
plane

No impairment

P3356

ETALDOC 591/9

Page 6 of 6

December 2003

CONSTRUCTION

Dimensions shown are in millimetres (inches).

Geometric centres of outline and pin grid coincide within a tolerance circle of 0.6mmØ.

Windings may be used interchangeably as primary or secondary.

Total weight typically 6.3g.

ABSOLUTE MAXIMUM RATINGS

INTELLECTUAL PROPERTY RIGHTS

(Ratings of components independent of circuit).

Short term isolation voltage (1s)

DC current
Storage temperature

Lead temperature, 10s

2.12kVrms,
3.0 kVDC
100

µ

A

-40ºC to
+85ºC
260ºC

ETAL and P3356 are Trade Marks of Profec

Technologies Ltd.

The Trade Mark ETAL is registered at the UK

Trade Marks Registry.
Profec Technologies Ltd. is the owner of the

design right under the Copyright Designs and

Patents Act 1988 and no rights or licences are

hereby granted or implied to any third party.
British Patent Nos. 2333646; 2340667.

USA Patent No. 6, 344, 787

European Patent No. 1082734

Singapore Patent No. 77763

Australia Patent No. 756952

UK Registered Design No. 2077360.

French Registered Design No. 991512.

Germany Registered Design 49902311.0.

United States Registered Design 426, 815.

Mexico Registered Design 12143

Other patents and registered designs pending.
© 1998 - 2003 Profec Technologies Ltd.

Reproduction prohibited.

T R A N S F O R M I N G    T H E    F U T U R E

Profec Technologies Ltd., 10 Betts Avenue, Martlesham Heath, Ipswich, IP5 3RH, England

                           Telephone: +44 (0) 1473 611422

Fax:  +44 (0) 1473 611919

Website: www.profec.com 

Email:  info@profec.co.uk  sales@profec.com

Connections

Dimensions

FM 25326

ISO 9001

E203175