| 摘要 |
A voltage reference circuit comprises a voltage-controlled current source 2,8,10; a first reference metal-oxide-semiconductor field-effect transistor (MOSFET) 4 and a second reference MOSFET 6, wherein the threshold voltage of the two MOSFETs are different; a current mirror 12; and a load 18. The voltage-controlled current source generates a first current proportional to a difference between the threshold voltages of the first and second MOSFETs, and the current mirror 12 generates a second current, that is a scaled version of the first current, through the load 18 so as to produce a reference voltage. The voltage controlled current source can be an operational transconductance amplifier and the threshold voltage of the first MOSFET 4 can be higher than the threshold voltage of the second MOSFET 6. The reference transistors can be diode-connected and there may be a resistor 14 in series with the drain of the second MOSFET 6 having the lower threshold, the difference in threshold voltage being generated across the resistor. The current mirror can comprise transistors of different widths whose gates are connected to a common voltage. The load can be a resistor that is variable in steps using a digital control signal. |
