Overstress management for power amplifiers

• US 9,787,270 B2
• Filed: 11/26/2014
• Issued: 10/10/2017
• Est. Priority Date: 11/26/2013
• Status: Active Grant

• Current Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Original Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Inventors: Scott, Baker, Maxim, George, Leipold, Dirk Robert Walter
• Primary Examiner(s): Mottola, Steven J
• Assistant Examiner(s): Rahman, Hafizur
• Application Number:
  US14/554,681
• Publication Number:
  US 20150145594A1
• Time in Patent Office: 1,049 Days
• Field of Search: 330135, 330156, 330183, 330207, 330250, 330253, 330264, 330269, 330277, 330298, 330298 P
• CPC Class Codes: H03F 1/0211 with control of the supply voltage or current
• CPC Class Codes: H03F 1/0272 by using a signal derived from the output signal
• CPC Class Codes: H03F 1/223 with MOSFET's
• CPC Class Codes: H03F 1/32 Modifications of amplifiers to reduce non-linear distortion by negative feedback H03F1/34
• CPC Class Codes: H03F 1/523 for amplifiers using field-effect devices H03F1/526 takes precedence
• CPC Class Codes: H03F 1/565 using inductive elements
• CPC Class Codes: H03F 2200/324 An amplitude modulator or demodulator being used in the amplifier circuit
• CPC Class Codes: H03F 2200/387 A circuit being added at the output of an amplifier to adapt the output impedance of the amplifier
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2200/471 the voltage being sensed
• CPC Class Codes: H03F 2201/3236 A generated signal, e.g. a pulse or an inverted synchronous signal, being added to avoid certain conditions, e.g. clipping
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/193 with field-effect devices H03F3/195 takes precedence
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H03F 3/45179 using MOSFET transistors as the active amplifying circuit H03F3/45278 takes precedence
• CPC Class Codes: H03F 3/45394 Pl types H03F3/45421, H03F3/45448 take precedence
• CPC Class Codes: H03F 3/68 Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602
• CPC Class Codes: H03G 3/3036 in high-frequency amplifiers or in frequency-changers H03G3/3052, H03G3/32, H03G3/34 take precedence
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 2001/0408 : with power amplifiers
• CPC Class Codes: H04B 2001/0416 : having gain or transmission power control
• CPC Class Codes: H04B 2001/0425 : with linearisation using predistortion

Abstract

A power amplifier includes an amplifier element and overstress management circuitry coupled to the amplifier element. The overstress management circuitry is configured to detect an overstress condition of the amplifier element and adjust one or more operating parameters of the amplifier element in response to the detection of an overstress condition of the amplifier element. Using the overstress management circuitry prevents damage to the amplifier element that may occur due to uncorrected overstress conditions which may degrade or destroy a gate oxide of the amplifier element. Accordingly, the longevity of the amplifier element is improved.

Claims

1. A power amplifier comprising:

an amplifier element configured to receive and amplify a radio frequency (RF) input signal to provide an RF output signal; and

overstress management circuitry comprising;

overstress sensor circuitry comprising a hot carrier injection (HCI) overstress sensor coupled to the amplifier element, the overstress sensor circuitry configured to;

detect an overstress condition of the amplifier element; and

produce an overstress indicator signal; and

overstress control circuitry coupled to the overstress sensor circuitry and configured to adjust one or more operating parameters of the amplifier element in response to the overstress indicator signal.

2. The power amplifier of claim 1 wherein the amplifier element is a transistor including a gate contact, a drain contact, a source contact, and a bulk contact.

3. The power amplifier of claim 2 wherein the overstress management circuitry comprises a capacitor coupled between the source contact and the drain contact of the transistor and configured to reduce a voltage between the gate contact and the source contact when a voltage above a predetermined threshold is present between the drain contact and the source contact.

4. The power amplifier of claim 1 wherein the overstress sensor circuitry comprises:

input filtering circuitry;

transfer function circuitry coupled to an output of the input filtering circuitry; and

output filtering circuitry coupled to an output of the transfer function circuitry.

5. The power amplifier of claim 4 wherein:

the input filtering circuitry is configured to receive an overstress measurement signal from the amplifier element and filter out high frequency components of the overstress measurement signal to produce a filtered overstress measurement signal;

the transfer function circuitry is configured to perform a non-linear signal transformation on the filtered overstress measurement signal to generate a transformed overstress measurement signal; and

the output filtering circuitry is configured to filter the transformed overstress measurement signal to generate the overstress indicator signal.

6. The power amplifier of claim 4 wherein the overstress sensor circuitry further comprises integrator circuitry coupled between the transfer function circuitry and the output filtering circuitry.

7. The power amplifier of claim 6 wherein:

the input filtering circuitry is configured to receive an overstress measurement signal from the amplifier element and filter out high frequency components of the overstress measurement signal to produce a filtered overstress measurement signal;

the transfer function circuitry is configured to perform a non-linear signal transformation on the filtered overstress measurement signal to generate a transformed overstress measurement signal;

the integrator circuitry is configured to receive and integrate the transformed overstress measurement signal to generate a transformed and integrated overstress measurement signal; and

the output filtering circuitry is configured to filter the transformed and integrated overstress measurement signal to generate the overstress indicator signal.

8. The power amplifier of claim 1 wherein the overstress control circuitry is configured to adjust a biasing voltage provided to the amplifier element in response to the overstress indicator signal.

9. The power amplifier of claim 1 wherein the overstress control circuitry is configured to adjust one of the RF input signal and the RF output signal in response to the overstress indicator signal.

10. The power amplifier of claim 1 wherein:

the RF input signal is provided to an input of the amplifier element and the RF output signal is provided at an output of the amplifier element; and

the overstress control circuitry is configured to adjust an impedance presented to the output of the amplifier element in response to the overstress indicator signal.

11. The power amplifier of claim 10 further comprising output waveform shaping circuitry configured to receive a control signal from the overstress control circuitry and adjust an LC harmonic trap circuit in response to the control signal.

12. The power amplifier of claim 2 wherein the overstress sensor circuitry is configured to measure a bulk current of the amplifier element.

13. The power amplifier of claim 1 wherein the overstress sensor circuitry further comprises a gate oxide integrity (GOI) overstress sensor.

14. The power amplifier of claim 13 wherein the overstress sensor circuitry is configured to measure a bulk current of the amplifier element and a voltage between one or more contacts of the amplifier element.

15. The power amplifier of claim 13 wherein the overstress sensor circuitry is configured to measure a root mean square (RMS) voltage between one or more contacts of the amplifier element.

16. The power amplifier of claim 13 wherein the overstress control circuitry is configured to adjust a biasing voltage provided to the amplifier element in response to the overstress indicator signal.

17. The power amplifier of claim 13 wherein the overstress control circuitry is configured to adjust an input signal provided to the amplifier element in response to the overstress indicator signal.

18. The power amplifier of claim 13 wherein the overstress control circuitry is configured to adjust an impedance at an output of the amplifier element in response to the overstress indicator signal.

19. A power amplifier comprising:

a plurality of amplifier elements configured to receive a radio frequency (RF) input signal at an input, amplify the RF input signal, and provide an RF output signal at an output; and

overstress management circuitry comprising;

overstress sensor circuitry comprising a hot carrier injection (HCI) overstress sensor coupled to the amplifier element, the overstress sensor circuitry configured to;

detect an overstress condition of the amplifier element; and

produce an overstress indicator signal; and

overstress control circuitry coupled to the overstress sensor circuitry and configured to;

adjust one or more operating parameters of the plurality of amplifier elements in response to the overstress indicator signal; and

adjust an impedance presented to the output of the plurality of amplifier elements in response to the overstress indicator signal.

20. The power amplifier of claim 19 wherein the overstress sensor circuitry further comprises a gate oxide integrity (GOI) overstress sensor.