| 摘要 |
PURPOSE:To reduce current consumption at self-refresh by controlling the drive of a substrate voltage generating circuit to drive by an internal clock at normal operation and by an external clock at refresh. CONSTITUTION:A control circuit 11 constituted by an input buffer section comprising TRQ9, Q10 and a switch section comprising TRQ11-Q14 is added to a conventional substrate voltage generating circuit, and the external clock signal phi1 is given to the former input and the internal clock signal phi2 or phi2' is given to a gate of the latter switching TRQ11-Q14. The signal phi2 goes to ''L'' at normal operation, the TRQ11, Q12 are turned on and an output of the oscillation section drives a charge pump section. The signal phi2 goes to ''H'' at selt-refresh, TRQ13, Q14 are turned on, and the charge pump section is driven by the signal phi1. The timer period is prolonged at self-refresh and the substrate current is decreased, then the period of the signal phi1 is prolonged and the current consumption of the substrate voltage generating circuit is reduced. |
