| 摘要 |
<p>PURPOSE:To give the hysteresis function stable against the variation in the power supply voltage and temperature, by parallelly inserting a clamp circuit to the resistor connected between the common emitter and the point at minimum potential. CONSTITUTION:When the input voltage V1 is at low level, the transistor Q1 is OFF and the transistor Q2 is ON. When the power supply voltage Vcc increases, the potential V4 at the point 4 is increased. Then, a current gradually flows to the diodes D3-D5 and the potential of V4 is clamped with the diodes D3-D5 around VTH (where; VTH is the threshold voltage of the transistor Q1) - V4=2.0V (that is, Vcc=5.8V). Since VTH is suppressed with the diodes D3-D5 even with higher power supply voltage Vcc, the permissible range of the power supply voltage Vcc can be taken greater.</p> |
