Invention Grant
- Patent Title: Direct coupling type power amplifier circuit
- Patent Title (中): 直接耦合型功率放大电路
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Application No.: US766725Application Date: 1977-02-08
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Publication No.: US4063185APublication Date: 1977-12-13
- Inventor: Shinichi Kojima , Yoshio Sakamoto
- Applicant: Shinichi Kojima , Yoshio Sakamoto
- Applicant Address: JA
- Assignee: Hitachi, Ltd
- Current Assignee: Hitachi, Ltd
- Current Assignee Address: JA
- Priority: JA51-18990 19760225
- Main IPC: H03F1/00
- IPC: H03F1/00 ; H03F1/30 ; H03F3/183 ; H03F3/20 ; H03F3/30 ; H03F3/34 ; H03F3/343 ; H03F3/45 ; H03F3/04
Abstract:
In a direct coupling type power amplifier circuit comprising an input differential amplifier stage, a drive amplifier stage responsive to the output signal of the input differential amplifier stage dc-wise and ac-wise, and a push-pull output amplifier stage responsive to the output signal of the drive amplifier stage dc-wise and ac-wise, the input differential amplifier stage being supplied at one input electrode thereof with an input signal and at the other input electrode thereof with the output of the push-pull output amplifier stage through a negative feedback circuit network, the power amplifier circuit further comprises a bias circuit network for defining the dc bias current through the input differential amplifier stage and a delay circuit coupled between the bias circuit network and a power source voltage supply point. With this circuit arrangement, the dc bias current through the input differential amplifier stage is cut off to hold the whole power amplifier circuit non-responsive to the input signal during a predetermined time internal after the application of the power source voltage to the power source voltage supply point, the predetermined time interval being substantially determined by a predetermined delay time in the delay circuit and a predetermined constant voltage value of a constant voltage circuit component in the bias circuit network.
Public/Granted literature
- US5801147A Polypeptides and use thereof Public/Granted day:1998-09-01
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