T622.K (04/12)

3

pulseelectronics.com

T1/E1/CEPT/ISDN-PRI TRANSFORMERS

Quad Port T1/E1 with 8 Transformers, 1500 Vrms

Application

Typical Application

1. ET Product - All coils have an ET product of 10 V-μsec

minimum.

2. Flammability - Materials used in the products are

recognized as UL94-VO approved. Products meet the

IEC 695-2-2 requirements (Needle Flame Test).

3. Balance Characteristics - The transformers meet the

requirements for longitudinal balance of FCC part 68.

4. Common Mode Rejection Ratio - the CMRR for all

transformers is better than 50dB at 1MHz. A typical test

circuit is shown below.

5. Crosstalk Attentuation - In the packages which contain

transmit and receive transformers side by side, sufficient

crosstalk attentuation is achieved by the inherent

characteristics of the toroid cores as well as by their

proper positioning. The crosstalk attentuation is typically

65 dB or better. This result was established with the test

circuit shown below.

6. 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

with the situations where they are applicable.

Frequency

50-100 kHz

10 kHz-2MHz

2-3 MHz

Return Loss

Transmit

9 dB

15 dB

11 dB

Receive

12 dB

18 dB

14 B

7. Surge Voltage Capability - All transformers and chokes meet

surge voltage tests according to the most stringent regulatory

documents, when used with the proper voltage and current

suppression devices:

Metallic Voltage: 800 V peak, 10/560

μsec

Longitudinal Voltage:

2,400 V peak, 10/700

μsec

8. Isolation Voltage - 100% of transformers are tested during the

specified isolation voltage level.

9. 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.

10. Common Mode Chokes - Additional high-frequency 4-line

common mode chokes may be used to provide an effective

means of complying with national and international regulations

on EMI. The common mode chokes are designed to be used in

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

typical application below. Crosstalk is typically -65 dB or better.

HP-8751A

P1 P2

50:100

BALUN

100:50

BALUN

XFMR

50:100

BALUN

100:50

BALUN

XFMR

HP-8751A

P1 P2

100

100