| 摘要 |
PROBLEM TO BE SOLVED: To easily and exactly test a desired internal voltage by comparing the voltage corresponding to the reference voltage generated by a reference voltage generating means with that on the internal power source line, adjusting the voltage level on the internal power source line in compliance with this result, generating a voltage at the substantially equal voltage level to the reference voltage and transmitting it to the pad. SOLUTION: A reference voltage generating circuit RFG in the internal power source circuit has a very small current feeding power because it is made low in power consumption. On the other hand, a comparator CMP in an internal voltage descending circuit VDC has a very high impedance and even when the current feeding power of the reference voltage Vref is very low, the load accompanying the output of the reference voltage generating circuit RFG is small and generates stable reference voltage Vref. A driving circuit 2 is activated when the test mode indicating signal TF is activated and generates a reference voltage Vrfo of the voltage level corresponding to the reference voltage Vref with a comparatively large current driving power to transmit to the pad 1. |
