T1/CEPT/ISDN-PRI TRANSFORMERS

Application Notes

NOTES FROM TABLES (pages 1 through 6):

A. Toleranced leakage inductance: .30µH min to .55µH MAX.

B. OCL (primary inductance) and LL (leakage inductance) are

measured at the primary winding. Turns ratio is specified

primary: secondary. (CT = Center Tap; CS = Split Center

Tap).

C. To make a 1CT:1 ratio from a 1CT:2CT ratio, use only one

half of the secondary (2CT) winding.

D. For Reinforced 3kVrms Dual SMT Transformers, refer to

data sheet T617. For Quad SMT Transformers refer to data

sheet T615. For Octal SMT Transformers refer to data

sheet T622.

E. Dual Ratio Transformers — These transformers have

tapped secondary windings to provide two turns ratios

(T/R). Use the entire primary winding and connect the sec-

ondary pins listed below to obtain the desired turns ratio:

Part

Turns Secondary Turns Secondary

Number

Ratio 1

Pins

Ratio 2

Pins

PE-65837

1:1.08

3-5

1:1.36

1

-

5

PE-65839

1:1

3-5

1:1.26

1

-

5

PE-65866

1:1

2-3

1:1.26

1

-

3

PE-68646

1:1.58

3-5

1:2

1

-

5

PE-65389

1:1

3-5

1:1.26

1

-

5

PE-65566

1:1

2-3

1:1.26

1

-

3

PE-65568

1:1

2-3

1:1.26

1

-

3

PE-68866

1:1

2-3

1:1.26

1

-

3

PE-68826

1:1

2-3

1:1.26

1

-

3

PE-68664

1:1

3-5

1:1.26

1

-

5

PE-68836

1:1

2-3/5-6

1:1.26

1-3/4-6

F. Standard packaging for surface mount “AN” and “LA” pack-

ages is anti-static tubes. Optional Tape & Reel packaging

can be ordered by adding “T” suffix to the part number,

(i.e. PE-65857T).

G. PE-68618 and PE-64950: The fault locate winding is (7-8).

H. Safety Agency approvals pending.

I. The turns ratio of these devices have been designed, in

conjunction with semiconductor vendor recommendations,

to allow connections to various terminations (e.g. 75 or

120

Ω with the same transformer). For example T1075 can

be used with the Siemens PEB 2235 to achieve connection

to the 75 or 120

Ω cable. For 75 Ω termination, the PEB

2235 requires the following turns ratio: 1:1.57 (Tx) and

1:1.26 (Rx) which can be achieved using pins (1-2):(15-16)

for Tx and (10-11):(5-8) for Rx. For 120

Ω, the following

turns ratio are required: 1:2 (Tx) and 1:1 (Rx), which are

pins (1-2):(16-14) for Tx and (9-11):(5-8) for Rx on the

T1075.

1. Extended Temperature Range Models — For extended temperature range

transformers (-40°C to +85°C operating temperature range), OCL (Open

Circuit Inductance for the primary winding) is specified at both -40°C and

+25°C. At -40°C, OCL is 600 µH minimum for all low temperature models with

the exception of PE-68827 which is 800 µH minimum and PE-65836 which is

300 µH minimum. All other parameters are specified at +25°C only. Standard

temperature range is 0°C to +70°C.

2. ET Product — All coils have an ET product of 10 V-µsec minimum.

3. Flammability — Materials used in the products are recognized

as UL94-VO approved. Products meet the requirements of IEC 695-2-2

(Needle Flame Test).

4. Balance Characteristics — The transformers meet the requirements for lon-

gitudinal balance of FCC part 68.

5. Common Mode Rejection Ratio — the CMRR for all transformers is better

than 50 dB at 1 MHz. A typical test circuit is shown below.

6. Crosstalk Attenuation — In the dual packages, which contain transmit and

receive transformers side by side, sufficient crosstalk attenuation is achieved

by the inherent characteristics of the toroid cores as well as by their proper

positioning. The crosstalk attenuation is typically50 dB or better from 100kHz

to 10MHz. This result was established with the test circuit shown below.

7. Return Loss — ITU-T G.703 and European national regulatory documents

specify minimum return loss levels. The transformers will allow these limits to

be complied within the situations where they are applicable.

Frequency

50-100kHz

100kHz-2 MHz

2-3MHz

Return Loss

XMIT

9 dB

15dB

11dB

REC

12 dB

18dB

14dB

8. Surge Voltage Capability – All transformers and chokes meet surge voltage

tests according to the most stringent regulatory documents when system

designs include the proper voltage and current suppression devices:

Metallic Voltage:

800V peak, 10/560µsec

Longitudinal Voltage:

2,400V peak, 10/700µsec

9.

Isolation Voltage — 100% of transformers are tested during

production to the specified isolation voltage level.

10. Safety Agency Recognition — Parts listed as "Recognized" or "Certified"

meet Underwriter Laboratories, UL 1459 and UL 1950 per file E133523 (S).

Transformers with Reinforced Insulation according to IEC950 series

PE-68630—PE-68788 (pg. 3) are certified by the following organizations:

Code

Certificate Information

T

TÜV, EN 60 950/EN 41003, Cert. R9371358, reinforced insulation.

U

UL 1459/UL1950, File E133523 (S), reinforced insulation.

11. General Information — The transformers are specifically designed for use

in 1.544 Mbps (T1), 2.048 Mbps (CEPT) and ISDN Primary rate (PRI)

interface applications. They are matched to the majority of the line interface

transceiver ICs currently available. Use of the proper transformer allows the

interface circuit to comply with ITU-T G.703 and other standards regarding

pulse waveform, return loss, and balance.

12. Common Mode Chokes — The “high-frequency” 4-lines common mode

chokes shown in this data sheet provide an effective means of compliance with

national and international regulations on EMI. They are designed to be used in

conjunction with Pulse’s T1/CEPT transformers as shown in the typical

application below. Crosstalk is typically -70dB at 1MHz and -55dB at 10MHz.

HP-8751A

P1 P2

50:100

BALUN

100:50

BALUN

XFMR

50:100

BALUN

100:50

BALUN

XFMR

HP-8751A

P1 P2

100

100

IC

XMiT

Transformer

RCVE

Choke

Choke

Transformer

IC

RCVE

XMIT

Typical Application

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7

T608.S (4/08)