| 摘要 |
PROBLEM TO BE SOLVED: To discharge stored charges on output transistors for a short time in a transmission circuit of an ultrasonic diagnostic apparatus, and to make the transmission circuit operate over a broadband. SOLUTION: A constant-voltage circuit 30 is provided between the bases of transistors Q3, Q4 and is designed into a low-impedance circuit. A feedback resistor R3 is provided between an output point 26 and the mid point 28 of two constant-voltage circuits 32, 34. Since charges, stored at the bases of the transistors Q3, Q4 escape to transistors Q1, Q2 via the constant-voltage circuit 30, the feedback resistor R3 makes the transmission circuit operate over a broadband. COPYRIGHT: (C)2003,JPO
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