Patent DE922795C successfully refreshed from Google Patents.
Patent US6351632B1 successfully refreshed from Google Patents.
EP0399276A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Circuit for limiting temperature without distortion in audio power amplifiers
Assignee: STMicroelectronics SRL
•
Filing: 1990-05-07
•
Granted: —
•
Expires: 2010-05-07
Abstract
Abstract A circuit for limiting temperature without distortion in audio power amplifiers, comprising a temperature sensor (2) for sensing the temperature in an audio power amplifier (1), and a variable-gain amplifier (5) connected ahead of the audio power amplifier circuit and having a gain control input (6) connected to the temperature sensor to vary the input signal of the audio amplifier in a linear manner. A linear limitation of the power, and therefore of the temperature, is thus obtained in the audio amplifier without introducing distortion.
Inventors
- 👤 Edoardo Botti
- 👤 Fabrizio Stefani
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 06:39
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/52; H03F2200/00; H03F2200/447
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
53 words
A circuit for limiting temperature without distortion in audio power amplifiers, comprising a temperature sensor (2) for sensing the temperature in an audio power amplifier (1), characterized by a variable-gain amplifier (5) connected ahead of said audio power amplifier (1) circuit and having a gain control input (6) connected to said temperature sensor.
Claim 2
Dependent Claim
53 words
A circuit for limiting temperature without distortion in audio power amplifiers, comprising a temperature sensor (2) for sensing the temperature in an audio power amplifier (1), characterized by a variable-gain amplifier (5) connected ahead of said audio power amplifier (1) circuit and having a gain control input (6) connected to said temperature sensor.
Claim 3
Dependent Claim
22 words
A circuit according to claim 1, characterized by a comparator (3) connected between said temperature sensor (2) and said variable-gain amplifier (5).
Claim 4
Dependent Claim
19 words
A circuit according to any of the preceding claims, characterized in that said comparator (3) is a hysteresis comparator.
Claim 5
Dependent Claim
26 words
A circuit according to any of the preceding claims, characterized by low-pass filter means (4) interposed between said hysteresis comparator (3) and said variable-gain amplifier (5).
Claim 6
Dependent Claim
69 words
A circuit according to any of the claims 1-3, characterized in that said comparator (3) has an output connected to an OR gate (11) which also receives at the input the output signal of a clipping sensing circuit (10), said OR gate being connected at the output to a pair of 6 filter means (12,13), respectively of the high-pass and low-pass type, for discriminating between temperature and clipping signals.
Claim 7
Dependent Claim
54 words
A circuit according to any of the preceding claims, characterized in that said temperature sensor (2) comprises a transistor (Q) which is biased so as to have a base- emitter drop which keeps said transistor (Q) off for temperatures below a preset threshold and switches said transistor (Q) on when said threshold is exceeded.
Claim 8
Dependent Claim
19 words
A circuit according to any of the preceding claims, characterized in that said variable-gain amplifier is a Gilbert multiplier.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.