SIGNAL CONDITIONING CIRCUIT BETWEEN AN OPTICAL DEVICE AND A PROCESSING UNIT
First Claim
1. A conditioning circuit for an external signal representative of a physiological quantity between an optical sensor and a processing unit, said received external signal being broken down into a useful component and an ambient component, wherein said conditioning circuit includes:
- a first stage including a transimpedance amplifier with an incorporated high pass filter using a feedback loop to subtract, at the stage input, the ambient signal component from the received external signal, and to deliver at output an amplified useful signal;
a second stage including a blocker sampler circuit for demodulating said amplified useful signal and delivering at output a demodulated useful signal; and
a third stage including a bandpass filter for filtering said demodulated useful signal in the frequency band of the physiological quantity to be detected and for transmitting a conditioned signal to said processing unit.
1 Assignment
0 Petitions
Accused Products
Abstract
The invention concerns a conditioning circuit (10) for an external signal (IN) representative of a physiological quantity, arranged between an optical sensor (11) and a processing unit (12), the received external signal (IN) being broken down into a useful component and an ambient component, characterized in that the conditioning circuit includes a first stage (13) including a transimpedance amplifier with an incorporated high pass filter (15) using a feedback loop to subtract the ambient signal component from the received external signal, and to deliver at output an amplified useful signal (IN1), a second stage (16) including a blocker sampler circuit (17) for demodulating the amplified useful signal and delivering at output a demodulated useful signal (IN2), and a third stage (18) including a bandpass filter (19) for filtering the demodulated useful signal in the frequency band of the physiological quantity to be detected and for transmitting a conditioned signal (OUT) to the processing unit.
-
Citations
14 Claims
-
1. A conditioning circuit for an external signal representative of a physiological quantity between an optical sensor and a processing unit, said received external signal being broken down into a useful component and an ambient component, wherein said conditioning circuit includes:
-
a first stage including a transimpedance amplifier with an incorporated high pass filter using a feedback loop to subtract, at the stage input, the ambient signal component from the received external signal, and to deliver at output an amplified useful signal; a second stage including a blocker sampler circuit for demodulating said amplified useful signal and delivering at output a demodulated useful signal; and a third stage including a bandpass filter for filtering said demodulated useful signal in the frequency band of the physiological quantity to be detected and for transmitting a conditioned signal to said processing unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 12, 13)
-
-
9. The integrated circuit including a conditioning circuit for an external signal representative of a physiological quantity between an optical sensor and a processing unit, said received external signal being broken down into a useful component and an ambient component, wherein said conditioning circuit includes:
-
a first stage including a transimpedance amplifier with an incorporated high pass filter using a feedback loop to subtract, at the stage input, the ambient signal component from the received external signal, and to deliver at output an amplified useful signal; a second stage including a blocker sampler circuit for demodulating said amplified useful signal and delivering at output a demodulated useful signal; and a third stage including a bandpass filter for filtering said demodulated useful signal in the frequency band of the physiological quantity to be detected and for transmitting a conditioned signal to said processing unit for receiving said external signal transmitted by said optical sensor and delivering a conditioned signal at output. - View Dependent Claims (10, 11, 14)
-
Specification