Integrated dual charge pump power supply including power down feature and rs-232 transmitter/receiver

摘要: A monolithic integrated circuit containing an inverting/non-inverting voltage doubler charge pump is disclosed for converting a unipolar supply to bipolar of greater magnitude. The input placed across first external transfer capacitor by set MOS switches during time period. source in series with the and this combination voltages reservoir second appearing on period third switches. into its polarity inverted fourth dual-collector lateral junction transistor, formed conventional CMOS processing steps used fabricate switches, connected as clamp between ground potential two DC output lines power assure correct start-up conditions circuit. Gain reduction devices are semiconductor substrate collect minority carriers which would otherwise be injected inherent parasitic four layer PNPN created result architecture circuit, prevent latch-up devices. In preferred embodiment, RS-232 receiver transmitter contained same dual supply.