HDSL2 Transformers
Document 202-1
Document 202-1 Revised 11/18/11
This family of transformers provides optimum perfor-
mance with the Level One SK70740/-41/-42 and other
HDSL2 transceiver chip sets. The series now includes
parts with a 1 CT to 2.3 CTS turns ratio, allowing them
to work with line drivers for lower power supply voltages.
They’re engineered for minimum DC resistance and
very low leakage inductance. Primary inductance with
and without DC bias is stable from -40°C to +85°C.
The return loss, longitudinal balance and THD are op-
timized for the best overall performance at the HDSL2
transmission speed.
For free evaluation samples or to discuss custom de-
signs, please contact Coilcraft.
Data Turns Primary Leakage
Part rate ratio inductance inductance Capacitance
DCR max (Ohms)
number Style (kb/s) chip:line ±15% (mH) max (µH) max (pF) Chip side Line side
H28161-A Leaded 1500 1 CT:2.3 CTS 2.0 25 90 1.5 (9-7) 1.5 (1-4), 1.5 (2-5)
H28159-A Leaded 1500 1 CT:2.3 CTS 2.0 30 55 2.0 (8-6) 2.0 (1-2), 2.0 (3-4)
H28160-A SMT 1500 1 CT:2.3 CTS 2.0 30 55 2.0 (8-6) 2.0 (1-2), 2.0 (3-4)
H27649-B Leaded 1500 1 CT:2 CTS 2.0 25 90 1.5 (9-7) 1.5 (1-4), 1.5 (2-5)
H27650-A Leaded 1500 1 CT:2 CTS 2.0 25 55 2.0 (8-6) 2.0 (1-2), 2.0 (3-4)
H27695-A SMT 1500 1 CT:2 CTS 2.0 25 55 2.0 (8-6) 2.0 (1-2), 2.0 (3-4)
H28223-B Leaded 1500 1 CT:2.3 CTS 2.0 30 65 1.85 (10-7) 2.1 (1-4), 2.1 (2-5)
H28224-B SMT 1500 1 CT:2.3 CTS 2.0 30 65 1.85 (10-7) 2.1 (1-4), 2.1 (2-5)
DC bias Dielectric Longitudinal
Part capacity strength
Return loss
balance THD
number (mA) (V) min (dB) min (dB) typ (dB) typ (dB)
H28161-A 100 2300 13 @ 40 kHz 13 @ 320 kHz 65 @ 40 kHz -85 @ 20 kHz
H28159-A 100 3000 13 @ 40 kHz 12 @ 320 kHz 65 @ 40 kHz -85 @ 20 kHz
H28160-A 100 3000 13 @ 40 kHz 12 @ 320 kHz 65 @ 40 kHz -85 @ 20 kHz
H27649-B 100 2300 14 @ 40 kHz 15 @ 320 kHz 65 @ 40 kHz -85 @ 20 kHz
H27650-A 100 3000 14 @ 40 kHz 13 @ 320 kHz 65 @ 40 kHz -85 @ 20 kHz
H27695-A 100 3000 14 @ 40 kHz 13 @ 320 kHz 65 @ 40 kHz -85 @ 20 kHz
H28223-B 100 3000 13 @ 40 kHz 13 @ 320 kHz 65 @ 40 kHz -85 @ 20 kHz
H28224-B 100 2300 13 @ 40 kHz 13 @ 320 kHz 65 @ 40 kHz -85 @ 20 kHz
1. All electrical specifications referenced to line side.
2. Operating temperature range -40°C to +85°C.
3. Electrical specifications at 25°C.
This product is not RoHS-compliant. Contact Coilcraft
for current status or possible alternatives.