US 8,575,998 B2 · Voltage reference circuit with temperature compensation

Abstract

A voltage reference circuit with temperature compensation includes a power supply, a reference voltage supply, a first PMOS transistor with its source connected to the power supply voltage, a second PMOS transistor with its source connected to the power supply and its gate and drain connected to the first PMOS gate, a first NMOS transistor with its gate and drain connected the first PMOS drain, a second NMOS transistor with its drain connected to the second PMOS drain and its gate connected with the first NMOS gate to the reference voltage supply, a resistor connected to the second NMOS source and ground, and an op-amp with its inverting input and its output connected the first NMOS source and its non-inverting input connected to the ground. In another aspect, a voltage reference circuit output is coupled to an NMOS gate in saturation mode connected to another voltage reference circuit.

Claims20

Dependent claims

A voltage reference circuit with temperature compensation, comprising:

a power supply;
a reference voltage supply;
a first PMOS transistor with a source connected to the power supply;
a second PMOS transistor with a source connected to the power supply and a gate and a drain connected together to the gate of the first PMOS;
a first NMOS transistor with a gate and a drain connected together to the drain of the first PMOS transistor;
a second NMOS transistor with a drain connected to the drain of the second PMOS transistor and a gate connected together with the gate of the first NMOS transistor to the reference voltage supply;
a resistor connected to the source of the second NMOS transistor and ground;
and
an op-amp having one inverting input, one non-inverting input, and an op-amp output, wherein the op-amp inverting input and the op-amp output are connected together to the source of the first NMOS transistor, and the op-amp non-inverting input is connected to the ground.

6 more elements

A voltage reference circuit with temperature compensation, comprising:

a power supply;
a reference voltage supply;
a first PMOS transistor with a source connected to the power supply;
a second PMOS transistor with a source connected to the power supply and a gate and a drain connected together to the gate of the first PMOS;
a first NMOS transistor with a gate and a drain connected together to the drain of the first PMOS transistor;
a second NMOS transistor with a drain connected to the drain of the second PMOS transistor and a gate connected together with the gate of the first NMOS transistor to the reference voltage supply;
a resistor connected to the source of the second NMOS transistor and ground;
and an op-amp having one inverting input, one non-inverting input, and an op-amp output,
wherein the op-amp inverting input and the op-amp output are connected together to the source of the first NMOS transistor, and the op-amp non-inverting input is connected to the ground, wherein the reference voltage supply is expressed by:
VREF
NEW
⁢
⁢
1
=
(
VirtualVSS
)
+
(
V
TH
+
2
⁢
I
ref
μ
N
⁢
C
ox
⁡
(
W
L
)
N
)
where VREFNew1 is the reference voltage supply, VirtualVSS is the op-amp output, VTH is the threshold voltage of the second NMOS transistor, Iref is the reference current of the voltage reference circuit, μN is the mobility of the second NMOS transistor, Cox is the gate oxide capacitance of the second NMOS transistor, W is the width of the channel of the second NMOS transistor, L is the length of the channel of the second NMOS transistor and N is an integer greater than 1.

37 more elements

Dependencies are inferred from the claim text.

Voltage reference circuit with temperature compensation

Life of this patent

Voltage reference circuit with temperature compensation

Life of this patent

Abstract

Claims20