Reference current source circuit and system

摘要

A reference current source circuit includes a reference voltage generating module, a voltage buffer, an equivalent resistance, a filter capacitor, a current mirror module and a reference current outputting terminal. The voltage buffer includes an operational amplifier and a first FET. The current mirror module includes a second FET and a third FET. The equivalent resistor includes an oscillator, a fourth FET, a fifth FET and a capacitor connected to the fourth FET and the fifth FET. The oscillator is for generating a clock signal whose frequency is related to a charging and discharging capacitor in the oscillator to control charging and discharging of the capacitor in the equivalent resistance. The reference current outputting terminal is for outputting a reference current only related to a capacitance ratio of the capacitor to the charging and discharging capacitor. A reference current source system is further disclosed.

主权项

1. A reference current source circuit comprising a reference voltage generating module, a voltage buffer connected to said reference voltage generating module, an equivalent resistor connected to said voltage buffer, a filter capacitor connected to said voltage buffer, a current mirror module connected to said voltage buffer and a reference current outputting terminal connected to said current mirror module, wherein said voltage buffer comprises an operational amplifier and a first FET connected to said operational amplifier; said current mirror module comprises a second FET and a third FET connected to said second FET; said equivalent resistor comprises an oscillator, a fourth FET connected to said oscillator, a fifth FET connected to said oscillator and a capacitor connected to said fourth FET and said fifth FET; a charging and discharging capacitor is provided in said oscillator; said oscillator is for generating a clock signal whose frequency is only related to said charging and discharging capacitor to control charging and discharging of said capacitor of said equivalent resistance; said reference current outputting terminal is for outputting a reference current related to a capacitance ratio of said capacitor to said charging and discharging capacitor.