Arrangement and method for providing a temperature-dependent signal
View Patent ↗An arrangement and a method for providing a temperature-dependent signal. Several current sources ( 1, 2 ) are provided, which are switchably connected to one or more diodes ( 8 ). The conducting-state voltage of the diode is compared with a reference signal (V r ) in a comparator ( 10 ). A control circuit ( 12 ) controls the current sources ( 1, 2 ) so that for calibrating in each calibration step, only one of the current sources is activated and, in another calibration step, all of the current sources ( 1, 2 ) are activated. Therefore, error terms can be calculated, which allow a very exact provision of a temperature-dependent signal with respect to the matching of the current sources to each other.
1. An arrangement for providing a temperature-dependent signal, comprising:
a first current source, which is switchably connected to a diode;
a second current source, which is switchably connected to the diode;
a comparator, which is coupled at one input to the first and to the second current source and which receives a reference signal at a second input; and
a control circuit with an input, which is coupled to an output of the comparator, and with outputs for connecting and disconnecting the current sources, such that for calibration in a first calibration state only the first current source is activated, in a second calibration state only the second current source is activated, and in a third calibration state all of the current sources are activated, and with an output of the control circuit for providing the temperature-dependent signal in a normal operating mode.
2. The arrangement according to claim 1 , wherein the control circuit includes means for calculating and compensating errors as a function of the comparison results.
3. The arrangement according to claim 1 , wherein the control circuit includes error memories, wherein one of the error memories is assigned to each of the current sources.
4. The arrangement according to claim 1 , wherein an analog/digital converter is connected between the comparator and the control circuit.
5. The arrangement according to claim 1 , wherein the current sources are each designed equally with respect to the current intensity in the connected state.
6. The arrangement according to claim 1 , wherein, for switchably connecting the current sources, a switch is provided arranged with the associated current source in a common current path.
7. The arrangement according to claim 1 , wherein the current sources are controlled by a common bias source.
8. The arrangement according to claim 7 , wherein for controlling the current sources with the common bias source, a respective current mirror is provided, wherein a common input transistor of the current mirrors is comprised by the bias source.
9. An arrangement for providing a temperature-dependent signal, comprising
a first current source connected to a diode;
a second current source connected to the diode;
a comparator, which is coupled at one input to the first and to the second current source and which receives a reference signal at a second input;
a control circuit with an input, which is coupled to an output of the comparator, and with outputs for connecting and disconnecting the current sources, such that for calibration in a first calibration state only the first current source is activated, in a second calibration state only the second current source is activated, and in a third calibration state all of the current sources are activated, and with an output of the control circuit for providing the temperature-dependent signal in a normal operating mode; and
a common bias source configured to control the current sources, a respective current mirror being provided to control the current sources with the common bias source which comprises a common input transistor of each respective current mirror;
wherein one of a base signal and gate signal in an associated current mirror is switchable to connect and disconnect the current sources.
10. A method for providing a temperature-dependent signal comprising the steps of:
generating a first current with a first current source;
generating a second current with a second current source;
generating a third current with the first and the second current sources;
comparing a voltage across a diode carrying the first, the second, or the third current with a reference signal;
calculating error terms as a function of the three currents; and
providing a temperature-dependent signal compensated with respect to the error terms.
11. The method according to claim 10 , further comprising digitizing the comparison signal output in the comparison.