| 摘要 |
<p>A current switch (40) that is responsive to logic switching control signals (C, B, D) is used in a telephone circuit comprising a handset receive signal path and a speakerphone receive signal path for separation a received voice signal into either the handset or speakerphone receive path depending on the selected mode of operation of the telephone circuit. The current switch includes a pair of switched current mirrors (40,82) and clamp circuits (160,180) which are rendered active or inactive depending on the particular mode of operation. The clamp circuits maintain the dc voltage appearing at the input of each current mirror constant as the particular current mirror is switched between active and inactive states thereby inhibiting audible dc transients.</p> |
