Vehicle-mounted charge pump circuit has current mirror circuit with FETs interposed for electric current paths during charging and discharging of capacitor respectively, and input unit to input clock signal to switch ON/OFF capacitor

摘要

A constant-current charging and discharging circuit (17) has current mirror circuit (15) with field effect transistors (FETs) (3,4,10) interposed for electric current path (P1) during charging of capacitor (C1), and FET (7) interposed for electric current path (P2) during discharging of capacitor. A signal input unit (19) inputs clock signal that switches on FETs (8,9) alternately to switch ON/OFF capacitor.