| 摘要 |
<p>PURPOSE:To realize a current detecting method which has high detection precision and small power loss by providing a collector electrode for current detection separately from a collector electrode for leading out a current, and detecting the voltage drop between both electrodes. CONSTITUTION:A bipolar output transistor (TR) 100 consists of a P-type sub strate 10, an N<+> type buried layer 20, a collector 20 made of an N-type epitaxial layer, an emitter diffusion part 40 made of an N<+> layer, and a P type base diffusion part 50 which surrounds the emitter. Contact parts 60 and 70 of the collector 30 are arranged on both sides of the emitter and base. Here, a collector electrode 90 is used for leading out a collector current and a collector electrode 93 is used for current detection. Then, the voltage drop DELTAV=I(Repi+RB/L) be tween the electrodes 90 and 93 is detected. In this case, I is the collector current of an output TR and Repi+RB/L is the sum of the resistance between the elec trode 90 and B/L buried layer and the resistance of the B/L buried layer up to right under the electrode 92, i.e. collector resistance.</p> |
