Power supply regulator circuit for voltage-controlled oscillator
First Claim
1. An apparatus including a power supply regulator circuit with increased rejection of variations and noise in power supply voltage, comprising:
- a power supply terminal configured to couple to a power supply and convey therefrom a supply voltage and a supply current;
a regulated circuit terminal configured to convey a regulated voltage and a first current;
a current replication circuit, coupled between said power supply and regulated circuit terminals, configured to receive said supply voltage, said supply current and said regulated voltage and in accordance therewith provide said first current and a second current, wherein said first and second currents are substantially mutually proportional; and
a voltage buffer circuit, coupled to said regulated circuit terminal, configured to receive and buffer a reference voltage and in accordance therewith provide said regulated voltage;
wherein variations and noise in said supply voltage appear as differences between said supply and regulated voltages across said current replication circuit and are thereby substantially prevented from appearing in said regulated voltage.
1 Assignment
0 Petitions
Accused Products
Abstract
A power supply regulator circuit with increased rejection of variations and noise in power supply voltage which is particularly well suited to isolating a voltage-controlled oscillator (VCO) from such power supply variations and noise. The regulator circuit uses an operational amplifier connected as a voltage follower circuit to buffer the reference voltage provided as the regulated supply potential for the VCO. This buffered voltage is also used to establish the bias voltage across a current mirror circuit which is powered by the unregulated power supply and through which the supply current for the VCO flows. This circuit topography requires no compensation capacitance and, therefore, provides increased rejection of variations and noise in the power supply voltage.
68 Citations
17 Claims
-
1. An apparatus including a power supply regulator circuit with increased rejection of variations and noise in power supply voltage, comprising:
-
a power supply terminal configured to couple to a power supply and convey therefrom a supply voltage and a supply current; a regulated circuit terminal configured to convey a regulated voltage and a first current; a current replication circuit, coupled between said power supply and regulated circuit terminals, configured to receive said supply voltage, said supply current and said regulated voltage and in accordance therewith provide said first current and a second current, wherein said first and second currents are substantially mutually proportional; and a voltage buffer circuit, coupled to said regulated circuit terminal, configured to receive and buffer a reference voltage and in accordance therewith provide said regulated voltage; wherein variations and noise in said supply voltage appear as differences between said supply and regulated voltages across said current replication circuit and are thereby substantially prevented from appearing in said regulated voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. An apparatus including a voltage-controlled oscillator with increased rejection of variations and noise in power supply voltage, comprising:
-
a power supply terminal configured to couple to a power supply and convey therefrom a supply voltage and a supply current; a regulated circuit terminal configured to convey a regulated voltage and a first current; a first current mirror circuit, coupled between said power supply and regulated circuit terminals, configured to receive said supply voltage, said supply current and said regulated voltage and in accordance therewith provide said first current and a second current, wherein said first and second currents are substantially mutually proportional; a voltage buffer circuit, coupled to said regulated circuit terminal, configured to receive and buffer a reference voltage and in accordance therewith provide said regulated voltage; and a voltage-controlled oscillator circuit, coupled to said regulated circuit terminal, configured to receive said regulated voltage, said first current and a control voltage and in accordance therewith provide an oscillator signal with a frequency that varies in relation to said control voltage; wherein variations and noise in said supply voltage appear as differences between said supply and regulated voltages across said current mirror circuit and are thereby substantially prevented from appearing in said regulated voltage. - View Dependent Claims (12, 13, 14, 15, 16, 17)
-
Specification