An internal power generating system for a semiconductor device is disclosed. The device may include a plurality of channels. The system comprises a reference voltage generator configured to generate a reference voltage. The system further comprises a plurality of internal power generators that are allocated to the plurality of channels in one-to-one correspondence and that are configured to commonly use the reference voltage generated by the reference voltage generator. Each internal power generator may be configured to receive a fed back internal power voltage, to compare the fed back internal power voltage to the reference voltage, and to generate an internal power voltage based on the comparison. The system further comprises a plurality of channel state detectors that are allocated to the plurality of channels in one-to-one correspondence, and that are configured to respectively detect operation states of the plurality of channels based on separate respective sets of command signals for each channel. The system additional comprises a plurality of internal power controllers that are allocated to the plurality of channels in one-to-one correspondence, and that are configured to respectively control driving capabilities for the internal power voltages according to the detected operation states.