PURPOSE: To prevent generation of noise by changing a drive transistor (TR) driving an output terminal stepwise from a cut-off state into a conduction state through the action of a stepwise control voltage generating means so as to prevent a steep change in an output current.
CONSTITUTION: A TR 44 is connected between a TR 43 and a ground potential VSS Then the TR 42 is conducted faster than the TR 43. Since a voltage being (power supply voltage-threshold voltage vth) is given to a gate of the TR 43 after a time t2, the TR 43 is turned on. Then a voltage of VSS+Vth is given to a gate of a TR 35 and the TR 35 is turned on after a time t3. Then after the time t3, a voltage level of an output signal S0 reaches the voltage TCC. As a result, the signal S0 outputted from a step control voltage generating circuit 201 is a signal waveform changed stepwise. Since the signal S0. is given to a gate of a driver TR 20, the TR changes from the interrupting state to the conductive state in response to the signal S0, then production of a steep change in the power supply is prevented.
SHIOMI TORU
NAKAOKA YOSHITO
| JPH02117210A | 1990-05-01 | |||
| JPH02237220A | 1990-09-19 | |||
| JPH03214812A | 1991-09-20 |