| 摘要 |
<p>PURPOSE:To obtain a non-volatile memory having the test function of a memory transistor in a short write time by providing a startup time constant change means for a high voltage pulse and a means to generate control signals with different pulse width. CONSTITUTION:When a selection signal STM is set at an 'H', and a gate 25 is closed, and the control signal, the inverse of SPRP is selected, and it is set at an 'L' at a time t1, FETs (Q1-Q3) are turned OFF and a Q4 is turned ON. Since a signal line L1 is grounded via the Q4 though switching capacitor 23 is activated, a high voltage generation circuit 20 rises steeply to a high voltage Vpp by a time constant only of the floating capacity of an output part. When the control signal, the inverse of SPRP is set at the 'H' after the lapse of around the half of the time t1, the Q3 is turned ON, and the capacitor 23 is inactivated, and the Q1 is turned ON, and the output of the high voltage generation circuit 20 is grounded compulsorily. Thus, since it is possible to rise the high voltage Vpp steeply by reducing the pulse width of the control signal, the inverse of SPRP to around the half, it is possible to apply an electric field larger than the ordinary one on the tunnel oxide film of a non-volatile memory device, and to perform the test of the memory transistor in the half time of an ordinary write time.</p> |
