Hammond 142D 600:600 Center-Tapped Open Frame PCB Audio Transformer

The 142D is a 600 ohm center-tapped to 600 ohm center-tapped audio transformer in the 142 Series open frame line, built for P.C. board mounting with a 1:1 turns ratio. It is listed for driver, input, interstage and isolation applications, and its drawing adds matching and pulse applications, suiting designers who need 600 ohm isolation on a circuit board.

Of the four 142 Series parts, the 142D carries the highest maximum unbalanced primary D.C. current at 15 mA. Power level is 100 mW from 200 Hz to 15 kHz, with frequency response within +/- 1 dB (ref. 1 kHz) at +10 dBm and +20 dBm. Total distortion is less than 0.5% for outputs at 200 Hz, decreasing at higher frequencies, and insertion loss is less than 1/2 dB. The secondary may be used as primary and vice versa.

Total winding D.C. resistance is 44 ohms primary and 58 ohms secondary. Typical inductance is 1.10 H on both primary (pins 1-3) and secondary (pins 4-6) at 1.0 kHz, 1.0 V, with 5.0 kΩ impedance on each and 0.072 H leakage inductance.

Construction is economical and open type, with pin terminals (0.0375" x .02") on pin bobbins set to a standard 0.187" grid pin spacing for P.C. board mounting. The windings are bifilar wound for balanced capacitive and resistance characteristics, and the insulation test is 1500 V rms. Net weight is 0.5 oz. Dielectric strength is 1500 Vrms; operating temperature is -40 to 85 °C and storage -40 to 105 °C. The 142D is RoHS and REACH compliant.