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US 11,079,781 B2Granted
Low quiescent fast linear regulator
AssigneeInfineon Technologies AG
InventorsDanilo Cellucci, Enrico Orietti
Life of this patent
Estimating the term…
Abstract
The disclosure is directed to techniques for a pass element in a linear regulator circuit. The pass element is configured with a transistor with a low input capacitance that provides current to the load for light current demand levels. When the output current exceeds a predetermined threshold, the pass element is configured to turn on a second transistor to provide the additional current. The configuration of the pass element with the regulator circuit causes the regulator circuit to operate with a low quiescent current and with large bandwidth for fast response to load changes.
Claims18
A linear regulator circuit comprising:
- an amplifier configured to:
- receive a voltage signal,
- receive a reference voltage signal,
- compare the voltage signal to the reference voltage signal, and
- generate a control signal based on the comparison, and
- a pass element configured to receive the control signal and provide an output current to a load of the linear regulator circuit based on the control signal, the pass element comprising a first transistor and a second transistor, wherein:
- the first transistor acts as a source follower to provide the output current to the load when the output current to the load is less than a predetermined threshold,
- in response to the output current to the load being less than the predetermined threshold the second transistor is switched off and the first transistor is switched on to provide all of the output current to the load,
- in response to the output current to the load being greater than or equal to the pre-determined threshold, the first transistor is switched on and the second transistor is switched on and the first transistor and the second transistor provide at least some of the output current, and
- a DC transfer function of the pass element of the linear regulator circuit is:
- G
- =
- V
- OUT
- V
- GATE
- =
- G
- MN
-
-
- 1
- +
- (
- 1
- +
- R
- P
-
- G
- MP
-
-
- 2
- )
-
- R
- LOAD
- 1
- +
- G
- MN
-
-
- 1
- +
- (
- 1
- +
- R
- P
-
- G
- MP
-
-
- 2
- )
-
- R
- LOAD
- wherein:
- G is the DC transfer function of the pass element,
- VGATE is an amplifier output voltage,
- VOUT is the voltage signal,
- GMN1 is a transconductance of the first transistor,
- GMP2 is a transconductance of the second transistor,
- RLOAD is an impedance of the load of the linear regulator circuit, and
- RP is an impedance value of a resistor coupled between a source and a gate of the second transistor.
66 more elements
A method comprising:
- receiving, by a pass element of a linear regulator, a control signal from an amplifier,
- providing, by the pass element, an output current to a load of the linear regulator circuit, wherein:
- the output current is based on the control signal,
- the pass element comprises a first transistor and a second transistor, wherein the first transistor acts as a source follower to provide the output current to the load when the output current to the load is less than a predetermined threshold,
- in response to the output current to the load being less than the predetermined threshold the second transistor is switched off and the first transistor s switched on to provides all of the output current to the load,
- in response to the output current to the load being greater than or equal to the pre-determined threshold, the first transistor is switched on and the second transistor is switched on and both the first transistor and the second transistor provide at least some of the output current, and
- a DC transfer function of the pass element of the linear regulator circuit is:
- G
- =
- V
- O
-
- U
-
- T
- V
- G
-
- A
-
- T
-
- E
- =
- G
- M
-
- N
-
- 1
- +
- (
- 1
- +
- R
- P
-
- G
- M
-
- P
-
- 2
- )
-
- R
- L
-
- O
-
- A
-
- D
- 1
- +
- G
- M
-
- N
-
- 1
- +
- (
- 1
- +
- R
- P
-
- G
- M
-
- P
-
- 2
- )
-
- R
- L
-
- O
-
- A
-
- D
- wherein:
- G is the DC transfer function of the pass element,
- VGATE is an amplifier output voltage,
- VOUT is the voltage signal,
- GMN1 is a transconductance of the first transistor,
- GMP2 is a transconductance of the second transistor,
- RLOAD is an impedance of the load of the linear regulator circuit, and
- RP is an impedance value of a resistor coupled between a source and a gate of the second transistor.
89 more elements
A circuit comprising a pass element configured to:
- receive a control signal and provide an output current to a load of a linear regulator circuit based on the control signal, the pass element comprising a first transistor and a second transistor, wherein:
- the first transistor acts as a source follower to provide the output current to the load when the output current to the load is less than a predetermined threshold,
- in response to the output current to the load being less than the predetermined threshold the second transistor is switched off and the first transistor is switched on to provide all of the output current to the load,
- in response to the output current to the load being greater than or equal to the predetermined threshold, the first transistor is switched on and the second transistor is switched on and both the first transistor and the second transistor provide at least some of the output current, and
- a DC transfer function of the pass element is:
- G
- =
- V
- O
-
- U
-
- T
- V
- G
-
- A
-
- T
-
- E
- =
- G
- M
-
- N
-
- 1
- +
- (
- 1
- +
- R
- P
-
- G
- M
-
- P
-
- 2
- )
-
- R
- L
-
- O
-
- A
-
- D
- 1
- +
- G
- M
-
- N
-
- 1
- +
- (
- 1
- +
- R
- P
-
- G
- M
-
- P
-
- 2
- )
-
- R
- L
-
- O
-
- A
-
- D
- wherein:
- G is the DC transfer function of the pass element,
- VGATE is an amplifier output voltage,
- VOUT is the voltage signal,
- GMN1 is a transconductance of the first transistor,
- GMP2 is a transconductance of the second transistor,
- RLOAD is an impedance of the load of the linear regulator circuit, and
- RP is an impedance value of a resistor coupled between a source and a gate of the second transistor.
87 more elements
Dependencies are inferred from the claim text.