Modem transformers all have numerous design requirements. Most of these are quite similar. A 1:1 turns ratio. 600 source impedance and about 300 modem load impedance. Frequency response, insertion loss, longitudinal balance, dielectric strength, return loss, are all important, but any correctly designed modem transformer should more than meet these customer requirements. HOWEVER, in today's modem transformers, the characteristic that separates the good from the mediocre, is distortion. Complicating this is the relative lack of standard requirements. A better modem can make up for a few more dBs of transformer distortion. A desire to trade cost for performance also plays it's part. Size vs performance is always there.

The following is a list of BG Labs modem/DAA microtransformer data sheets. These data sheets are provided in Adobe Acrobat format (.pdf). If you have the Adobe Acrobat reader simply download the datasheet onto your disk and view it using your reader.

The Adobe Acrobat Reader is provided free of charge to all users of the Windows or Mac operating systems.
To get your copy go to www.adobe.com and follow the road signs.

PCMCIA modem microtransformers:

K1 V.32bis microtransformer. (0.33 X 0.44 X 0.172, superior V.32)

KA 56K BPS transformer. (0.33 X 0.70 X 0.172, very low distortion, UL 1950 approved, and BABT approved.) Our smallest, globally qualified, high performance unit.

KC 56K BPS transformer. (0.33 X 0.44 X 0.172, excellent 56K)

KE 56K BPS transformer. (0.33 X 0.56 X 0.172, superior 56K)

KF V.34+ transformer. (0.54 X 0.70 X 0.172, excellent V.34, IEC 950 approved.)

KH 56K BPS transformer. (0.33 X 0.56 X 0.172 , IEC 950 approved excellent 56K)

KL V.34+ transformer. (0.54 X 0.70 X 0.172, superior V.34)

KP V.34 microtransformer. (0.33 X 0.44 X 0.172, excellent V.34)

KS 56K BPS transformer. (0.54 X 0.70 X 0.172, very low distortion, LUCENT TECHNOLOGIES referenced.)

KT 56K BPS transformer. (0.54 X 0.70 X 0.172, very low distortion, IEC 950 approved.)

NON PC CARD MODEM TRANSFORMERS:

KB 56K BPS microtransformer. (0.33 X 0.44 X 0.30, excellent 56K)

How does distortion affect modem performance.

How do you measure distortion.