Biometric sensor arrangement and method for generating a biometric signal

1. A biometric sensor arrangement, comprising:

a first radiation source,

a second radiation source that is realized as flash light-emitting diode which is implemented as white light-emitting diode and is fabricated for conducting a high current that is higher than 500 mA,

a driver coupled to the first and the second radiation source and configured to selectively operate the first and the second radiation source,

a photosensor and

a signal conditioning unit operable to provide a biometric signal,

wherein the signal conditioning unit comprises a transimpedance amplifier and an analog-to-digital converter,

wherein the transimpedance amplifier comprises an operational amplifier and a feedback resistor that couples a first input of the operational amplifier to an output of the operational amplifier

wherein a terminal of the photosensor is connected to the first input of the operational amplifier,

wherein a second input of the operational amplifier is connected to a reference potential terminal,

wherein the first input of the operational amplifier is an inverting input, and the second input of the operational amplifier is a non-inverting input, and

wherein the analog-to-digital converter is coupled to the output of the operational amplifier.

2. The biometric sensor arrangement according to claim 1 ,

wherein the photosensor is configured to provide a photon signal as a function of radiation emitted by the first radiation source.

3. The biometric sensor arrangement according to claim 1 ,

wherein the driver is configured to operate the first radiation source in a first operating phase and to operate the second radiation source in a second operating phase.

4. The biometric sensor arrangement according to claim 3 ,

wherein the signal conditioning unit is configured to provide the biometric signal depending on a photon signal generated by the photosensor in the first operating phase and independent from the photon signal in the second operating phase.

5. The biometric sensor arrangement according to claim 3 ,

wherein the driver is configured such that the second radiation source emits a flash in the second operating phase.

6. The biometric sensor arrangement according to claim 1 ,

wherein the first radiation source is configured to emit radiation at a first wavelength and the second radiation source is configured to emit radiation at a second wavelength that is different from the first wavelength.

7. The biometric sensor arrangement according to claim 1 ,

wherein the first and the second radiation source are realized as light-emitting diodes and form an anti-parallel circuit of diodes.

8. The biometric sensor arrangement according to claim 7 ,

wherein the driver is implemented as a H-bridge that is configured to supply the first and the second radiation source.

9. The biometric sensor arrangement according to claim 7 ,

wherein the driver comprises a current source, a further current source and a converter, and

wherein the further current source couples a supply terminal to a first driver terminal, the current source couples an output of the converter to the first driver terminal and the first driver terminal is coupled to a terminal of the first radiation source and to a terminal of the second radiation source.

10. The biometric sensor arrangement according to claim 7 ,

wherein the first radiation source is configured to protect the second radiation source in an event of an electrostatic discharge.

11. The biometric sensor arrangement according to claim 1 ,

wherein the first and the second radiation source are arranged in vicinity and are configured to emit radiation through the same opening of a housing.

12. The biometric sensor arrangement according to claim 1 ,

wherein the biometric sensor arrangement is configured to determine a heart rate of a user.

13. The biometric sensor arrangement according to claim 1 ,

wherein the biometric sensor arrangement is configured to determine the concentration of at least one parameter in a skin of a user of a group consisting of melanin, water, fat, alcohol and oxygen.

14. A mobile device, comprising the biometric sensor arrangement according to claim 1 ,

wherein the mobile device is realized as a mobile telecommunication device or a watch.

15. A method for generating a biometric signal, comprising:

selectively operating a first and a second radiation source by a driver, wherein the second radiation source is implemented as a flash radiation source,

providing a photon signal by a photosensor as a function of radiation emitted by the first radiation source and

providing the biometric signal by a signal conditioning unit as a function of the photon signal,

wherein providing the biometric signal comprises:

receiving the photon signal at a transimpedance amplifier of the signal conditioning unit, and

generating a modified photon signal using an analog-to-digital converter of the signal conditioning unit,

wherein the transimpedance amplifier comprises an operational amplifier and a feedback resistor that couples a first input of the operational amplifier to an output of the operational amplifier;

wherein a terminal of the photosensor is connected to the first input of the operational amplifier, and a second input of the operational amplifier is connected to a reference potential terminal,

wherein the first input of the operational amplifier is an inverting input and the second input of the operational amplifier is a non-inverting input, and

wherein the analog-to-digital converter is coupled to the output of the operational amplifier.

16. A biometric sensor arrangement, comprising:

a first radiation source,

a second radiation source that is implemented as a flash radiation source,

a driver coupled to the first and the second radiation source and configured to selectively operate the first and the second radiation source,

a photosensor and

a signal conditioning unit operable to provide a biometric signal,

wherein the signal conditioning unit comprises a transimpedance amplifier and an analog-to-digital converter,

wherein the transimpedance amplifier comprises an operational amplifier and a feedback resistor that couples a first input of the operational amplifier to an output of the operational amplifier

wherein a terminal of the photosensor is connected to the first input of the operational amplifier,

wherein a second input of the operational amplifier is connected to a reference potential terminal,

wherein the first input of the operational amplifier is an inverting input, and the second input of the operational amplifier is a non-inverting input,

wherein the analog-to-digital converter is coupled to the output of the operational amplifier

wherein the first and the second radiation source are realized as light-emitting diodes and form an anti-parallel circuit of diodes, and

wherein the first radiation source is configured to protect the second radiation source in an event of an electrostatic discharge.