| 摘要 |
<p>Gain control circuit for a telecommunication device to which DC current is supplied from an exchange. The control circuit includes a first voltage divider (R, R1/10) of which a number (R10; R10, 9; ... ; R12) of resistors are connected in parallel with NMOS transistors (NM1/9) having gates controlled from the tapping points (1/9) of a second voltage divider (R11/R19) fed by a constant current (I3) and from a voltage (VP) which is function of the DC current.</p> |
