Variable delta voltage tracking regulator and method therefor

• US 20020128049A1
• Filed: 01/08/2001
• Published: 09/12/2002
• Est. Priority Date: 01/08/2001
• Status: Active Grant

• Current Assignee: Temic Automotive of North America, Incorporated (Continental AG)
• Original Assignee: Scott B. Davis
• Inventors: Davis, Scott B.
• Granted Patent: US 6,947,774 B2
• Time in Patent Office: Days
• US Class Current: 455/572
• CPC Class Codes: H04B 15/005 Reducing noise, e.g. humm, from the supply

Abstract

A telematics communication system (100) receives an input supply voltage (Vin) (122) from a battery (102) charged by an alternator (101) in an automotive vehicle. The telematics communication system (100) includes a transceiver (104) having a transmitter (107) and a variable delta voltage tracking regulator (VDVTR) (109). The VDVTR (109) provides a regulated output supply voltage (Vout) (124) to a power amplifier (114) in the transmitter (107) responsive to the input supply voltage (122) and a regulator control voltage (TX_EN) (123). Unfortunately, the alternator (101) generates alternator whine noise (405) that appears on the input supply voltage (122) and, in turn, appears on the regulated output supply voltage (Vout) (124). The VDVTR (109) has a first operating stage and a second operating stage, each controlled by a bias circuit (R1, R2 and R3), and a third operating stage, controlled by a voltage limiting circuit (D1). The first operating stage of the bias circuit sets the regulated output supply voltage (Vout) (124) to be equal to the input supply voltage (122) (Vout=Vin) when the input supply voltage (122) is less than or equal to a first predetermined voltage (Vmin), responsive to the regulator control voltage (123) and the input supply voltage (122), to permit the presence of the alternator whine noise (405) on the regulated output supply voltage (Vout) (124) while giving operational priority to the transmit power output level of the transmitter (107). The second operating stage of the bias circuit sets the regulated output supply voltage (Vout) (124) to be equal to a predetermined function of the input supply voltage (Vin) (122) (Vout=mVin+b) when the input supply voltage (122) is between the first predetermined voltage (Vmin) and a second predetermined voltage (Vmax), greater than the first predetermined voltage (Vmin), responsive to the regulator control voltage (123) and the input supply voltage (122), to create an increasing voltage delta (404) between the input supply voltage (122) and the regulated output supply voltage (Vout) (124), thereby reducing the alternator whine noise (404) on the regulated output supply voltage (Vout) (124) while continuing to meet operational requirements of the transmit power output level of the transmitter (107). The third operating stage sets the regulated output supply voltage (Vout) (124) to be equal to a maximum predetermined voltage (Vmax) (Vout=Vmax) when the regulated output supply voltage (Vout) (124) is greater than or equal to the second predetermined voltage (Vmax), responsive to the regulator control voltage (123) and the input supply voltage (122) to limit the voltage supplied to the power amplifier 114.

Claims

1. A voltage regulator having a first terminal, a second terminal and a third terminal, the first terminal being coupled to receive an input supply voltage (Vin), the second terminal adapted to provide a regulated output supply voltage (Vout), the third terminal being coupled to receive a regulator control voltage, the voltage regulator comprising:

a bias circuit comprising;

a first resistor having a first terminal and a second terminal, the first terminal of the first resistor being coupled to the third terminal of the voltage regulator and being coupled to receive the regulator control voltage;

a second resistor having a first terminal and a second terminal, the first terminal of the second resistor being coupled to the second terminal of the first resistor, the second terminal of the second resistor being coupled to a ground potential; and

a third resistor having a first terminal and a second terminal, the first terminal of the third resistor being coupled to the second terminal of the first resistor and the first terminal of the second resistor, the second terminal of the third resistor being coupled to the input supply voltage; and

a summing circuit having a first terminal, a second terminal, a third terminal, a fourth terminal and a fifth terminal, the first terminal of the summing circuit, forming a first input of the summing circuit, being coupled to the second terminal of the first resistor and the first terminal of the second resistor and the first terminal of the third resistor, the second terminal of the summing circuit, forming a second input of the summing circuit, being coupled to the third terminal of the summing circuit, forming an output of the summing circuit to provide the regulated output supply voltage responsive to the regulator control voltage and the input supply voltage, the fourth terminal of the summing circuit, forming a third input of the summing circuit, being coupled to the input supply voltage, the fifth terminal of the summing circuit being coupled to the ground potential.

2. A voltage regulator according to claim 1 wherein the summing circuit further comprises an operational amplifier.

3. A voltage regulator according to claim 1 wherein voltage regulator has a first operating stage and a second operating stage, each determined by the bias circuit, the first operating stage of the bias circuit setting the regulated output supply voltage to be equal to the input supply voltage when the input supply voltage is less than or equal to a first predetermined voltage responsive to the regulator control voltage and the input supply voltage, and the second operating stage of the bias circuit setting the regulated output supply voltage to be equal to a predetermined function of the input supply voltage when the input supply voltage is between a first predetermined voltage and a second predetermined voltage, greater than the first predetermined voltage, responsive to the regulator control voltage and the input supply voltage.

4. A voltage regulator according to claim 1 further comprising:

a voltage limiting circuit having a first terminal and a second terminal, the first terminal of the voltage limiting circuit being coupled to the second terminal of the first resistor and the first terminal of the second resistor and the first terminal of the third resistor, the second terminal of the voltage limiting circuit being coupled to the ground potential.

5. A voltage regulator according to claim 4 wherein the voltage limiting circuit further comprises a zener diode.

6. A voltage regulator according to claim 4 wherein the voltage regulator has a third operating stage, determined by the voltage limiting circuit, setting the regulated output supply voltage to be equal to a maximum predetermined voltage when the regulated output supply voltage is greater than or equal to a second predetermined voltage responsive to the regulator control voltage and the input supply voltage.

7. A voltage regulator having a first terminal, a second terminal and a third terminal, the first terminal being coupled to receive an input supply voltage (Vin), the second terminal adapted to provide a regulated output supply voltage (Vout), the third terminal being coupled to receive a regulator control voltage, the voltage regulator comprising:

a bias circuit comprising;

a first resistor having a first terminal and a second terminal, the first terminal of the first resistor being coupled to the third terminal of the voltage regulator and being coupled to receive the regulator control voltage;

a second resistor having a first terminal and a second terminal, the first terminal of the second resistor being coupled to the second terminal of the first resistor, the second terminal of the second resistor being coupled to a ground potential; and

a third resistor having a first terminal and a second terminal, the first terminal of the third resistor being coupled to the second terminal of the first resistor and the first terminal of the second resistor, the second terminal of the third resistor being coupled to the input supply voltage;

a summing circuit having a first terminal, a second terminal, a third terminal, a fourth terminal and a fifth terminal, the first terminal of the summing circuit, forming a first input of the summing circuit, being coupled to the second terminal of the first resistor and the first terminal of the second resistor and the first terminal of the third resistor, the second terminal of the summing circuit, forming a second input of the summing circuit, being coupled to the third terminal of the summing circuit, forming an output of the summing circuit to provide the regulated output supply voltage responsive to the regulator control voltage and the input supply voltage, the fourth terminal of the summing circuit, forming a third input of the summing circuit, being coupled to the input supply voltage, the fifth terminal of the summing circuit being coupled to the ground potential; and

a voltage limiting circuit having a first terminal and a second terminal, the first terminal of the voltage limiting circuit being coupled to the second terminal of the first resistor and the first terminal of the second resistor and the first terminal of the third resistor, the second terminal of the voltage limiting circuit being coupled to the ground potential,

wherein voltage regulator has a first operating stage and a second operating stage, each determined by the bias circuit, the first operating stage of the bias circuit setting the regulated output supply voltage to be equal to the input supply voltage when the input supply voltage is less than or equal to a first predetermined voltage responsive to the regulator control voltage and the input supply voltage, and the second operating stage of the bias circuit setting the regulated output supply voltage to be equal to a predetermined function of the input supply voltage when the input supply voltage is between a first predetermined voltage and a second predetermined voltage, greater than the first predetermined voltage, responsive to the regulator control voltage and the input supply voltage, and

wherein the voltage regulator has a third operating stage, determined by the voltage limiting circuit, setting the regulated output supply voltage to be equal to a maximum predetermined voltage when the regulated output supply voltage is greater than or equal to a second predetermined voltage responsive to the regulator control voltage and the input supply voltage.

8. A voltage regulator according to claim 7 wherein the summing circuit further comprises an operational amplifier.

9. A voltage regulator according to claim 7 wherein the voltage limiting circuit further comprises a zener diode.

10. A telematics communication system comprising:

a telematics control unit;

a transceiver being coupled to the telematics control unit and being coupled to receive an input supply voltage (Vin) from a battery that is charged by an alternator in an automotive vehicle, the transceiver including;

a voltage regulator having a first terminal, a second terminal and a third terminal, the first terminal being coupled to receive the input supply voltage, the second terminal adapted to provide a regulated output supply voltage (Vout), the third terminal being coupled to receive a regulator control voltage, the voltage regulator including;

a bias circuit comprising;

a first resistor having a first terminal and a second terminal, the first terminal of the first resistor being coupled to the third terminal of the voltage regulator and being coupled to receive the regulator control voltage;

a second resistor having a first terminal and a second terminal, the first terminal of the second resistor being coupled to the second terminal of the first resistor, the second terminal of the second resistor being coupled to a ground potential; and

a third resistor having a first terminal and a second terminal, the first terminal of the third resistor being coupled to the second terminal of the first resistor and the first terminal of the second resistor, the second terminal of the third resistor being coupled to the input supply voltage; and

a summing circuit having a first terminal, a second terminal, a third terminal, a fourth terminal and a fifth terminal, the first terminal of the summing circuit, forming a first input of the summing circuit, being coupled to the second terminal of the first resistor and the first terminal of the second resistor and the first terminal of the third resistor, the second terminal of the summing circuit, forming a second input of the summing circuit, being coupled to the third terminal of the summing circuit, forming an output of the summing circuit to provide the regulated output supply voltage responsive to the regulator control voltage and the input supply voltage, the fourth terminal of the summing circuit, forming a third input of the summing circuit, being coupled to the input supply voltage, the fifth terminal of the summing circuit being coupled to the ground potential; and

a transmitter having a power amplifier being coupled to receive the regulated output supply voltage;

a user interface being coupled to the telematics control unit and the transceiver; and

an antenna being coupled to the transceiver.

11. A voltage regulator according to claim 10 wherein the summing circuit further comprises an operational amplifier.

12. A voltage regulator according to claim 10 wherein voltage regulator has a first operating stage and a second operating stage, each determined by the bias circuit, the first operating stage of the bias circuit setting the regulated output supply voltage to be equal to the input supply voltage when the input supply voltage is less than or equal to a first predetermined voltage responsive to the regulator control voltage and the input supply voltage, and the second operating stage of the bias circuit setting the regulated output supply voltage to be equal to a predetermined function of the input supply voltage when the input supply voltage is between a first predetermined voltage and a second predetermined voltage, greater than the first predetermined voltage, responsive to the regulator control voltage and the input supply voltage.

13. A voltage regulator according to claim 10 further comprising:

a voltage limiting circuit having a first terminal and a second terminal, the first terminal of the voltage limiting circuit being coupled to the second terminal of the first resistor and the first terminal of the second resistor and the first terminal of the third resistor, the second terminal of the voltage limiting circuit being coupled to the ground potential.

14. A voltage regulator according to claim 13 wherein the voltage limiting circuit further comprises a zener diode.

15. A voltage regulator according to claim 13 wherein the voltage regulator has a third operating stage, determined by the voltage limiting circuit, setting the regulated output supply voltage to be equal to a maximum predetermined voltage when the regulated output supply voltage is greater than or equal to a second predetermined voltage responsive to the regulator control voltage and the input supply voltage.

18. A method performed by a voltage regulator according to claim 17 wherein the second voltage level of the regulated output supply voltage is set equal to a function of the input supply voltage according to the equation:

Vout=mVin+b, wherein “

m”

is a first slope of a line forming a first linear relationship between Vin and Vout, and “

b”

is a constant that determines an offset of the line from an origin.

19. A method performed by a voltage regulator according to claim 17 wherein the first slope for the first linear relationship Vout=mVin+b is positive and less than a second slope for a second linear relationship Vout=Vin.

20. A method performed by a voltage regulator according to claim 17 wherein the second voltage level of the regulated output supply voltage is equal to:

a maximum predetermined voltage when the regulated output supply voltage is greater than or equal to the second predetermined voltage

16. An automotive vehicle comprising:

an alternator;

a battery being charged by the alternator and adapted to provide an input supply voltage (Vin) for electrical devices in the automotive vehicle;

a telematics communication system including;

a telematics control unit;

a transceiver being coupled to the telematics control unit and being coupled to receive the input supply voltage from the battery, the transceiver including;

a voltage regulator having a first terminal, a second terminal and a third terminal, the first terminal being coupled to receive the input supply voltage, the second terminal adapted to provide a regulated output supply voltage (Vout), the third terminal being coupled to receive a regulator control voltage, the voltage regulator including;

a bias circuit comprising;

a first resistor having a first terminal and a second terminal, the first terminal of the first resistor being coupled to the third terminal of the voltage regulator and being coupled to receive the regulator control voltage;

a second resistor having a first terminal and a second terminal, the first terminal of the second resistor being coupled to the second terminal of the first resistor, the second terminal of the second resistor being coupled to a ground potential; and

a third resistor having a first terminal and a second terminal, the first terminal of the third resistor being coupled to the second terminal of the first resistor and the first terminal of the second resistor, the second terminal of the third resistor being coupled to the input supply voltage; and

a summing circuit having a first terminal, a second terminal, a third terminal, a fourth terminal and a fifth terminal, the first terminal of the summing circuit, forming a first input of the summing circuit, being coupled to the second terminal of the first resistor and the first terminal of the second resistor and the first terminal of the third resistor, the second terminal of the summing circuit, forming a second input of the summing circuit, being coupled to the third terminal of the summing circuit, forming an output of the summing circuit to provide the regulated output supply voltage responsive to the regulator control voltage and the input supply voltage, the fourth terminal of the summing circuit, forming a third input of the summing circuit, being coupled to the input supply voltage, the fifth terminal of the summing circuit being coupled to the ground potential; and

a transmitter having a power amplifier being coupled to receive the regulated output supply voltage;

a user interface being coupled to the telematics control unit and the transceiver; and

an antenna being coupled to the transceiver.

17. A method performed by a voltage regulator comprising the steps of:

receiving an input supply voltage (Vin) and a regulator control voltage, the regulator control voltage having a first voltage level and a second voltage level; and

producing a regulated output supply voltage (Vout) having a first voltage level, being a ground potential, responsive to the first voltage level of regulator control voltage and having a second voltage level, being variable, responsive to the second voltage level of regulator control voltage and the input supply voltage,

wherein the second voltage level of the regulated output supply voltage is set;

equal to the input supply voltage when the input supply voltage is less than or equal to a first predetermined voltage, and

equal to a predetermined function of the input supply voltage when the input supply voltage is between a first predetermined voltage and a second predetermined voltage, greater than the first predetermined voltage, to create an increasing voltage delta between the input supply voltage and the regulated output supply voltage.

21. In a telematics communication system adapted for use in an automotive vehicle, a method for reducing alternator whine noise while giving operational priority to a transmit power output level of a transmitter using a voltage regulator, the voltage regulator being coupled to receive an input voltage supply (Vin) from a battery being charged by an alternator, being coupled to receive a regulator control voltage, and being adapted to provide a regulated output supply voltage (Vout), the regulated output supply voltage being coupled to a power amplifier in the transmitter, the method comprising the steps of:

producing a regulated output supply voltage (Vout), being variable, responsive to the regulator control voltage and the input supply voltage,

wherein the regulated output supply voltage is set;

equal to the input supply voltage when the input supply voltage is less than or equal to a first predetermined voltage to permit the presence of the alternator whine noise on the regulated output supply voltage while giving operational priority to the transmit power output level of the transmitter, and

equal to a predetermined function of the input supply voltage when the input supply voltage is between a first predetermined voltage and a second predetermined voltage, greater than the first predetermined voltage, to create an increasing voltage delta between the input supply voltage and the regulated output supply voltage, thereby reducing the alternator whine noise on the regulated output supply voltage while continuing to meet operational requirements of the transmit power output level of the transmitter.