Pluggable load module to test a voltage regulator
A test device for testing the invariability of the output voltage of a voltage regulator with transient loads, and the test device includes a switch connected with a switch drain contact to an output contact of the voltage regulator and with a switch source contact to ground potential, where a load resistance is arranged within this path from the output contact to ground potential, a switch driver connected with a switch driver output contact via a gate resistance to a switch gate contact to change the switch into a connected state, where the voltage regulator is loaded with a variable drain-source resistance of the switch and the load resistor, and to change the switch into a disconnected state, where the voltage regulator is disconnected from the load resistor, and a feedback resistor connected between the switch source contact and an inverted input contact of the switch driver.
1. A test device for testing the invariability of the output voltage of a voltage regulator with transient loads, which test device comprises:
a switch connected with a switch drain contact to an output contact of the voltage regulator and with a switch source contact to ground potential, wherein a load resistance is arranged within this path from the output contact to ground potential;
a switch driver connected with a switch driver output contact via a gate resistance to a switch gate contact to change the switch into a connected state, where the voltage regulator is loaded with a variable drain-source resistance of the switch and the load resistor, and to change the switch into a disconnected state, where the voltage regulator is disconnected from the load resistor;
a feedback resistor connected between the switch source contact and an inverted input contact of the switch driver;
a test signal source connected directly or via a D/A (digital-to-analog) converter to a direct input contact of the switch driver to provide at least a first test signal with a particular test signal form and frequency for changing the switch and varying the variable drain-source resistance of the switch; and
a current adjustment feedback driver connected with a direct input contact via an input resistor to the switch source contact and connected with an inverted input contact via a capacity to a ground contact and connected with a current adjustment feedback driver output contact via a compensator impedance to the inverted input contact of the current adjustment feedback driver to provide on the current adjustment feedback driver output contact a current adjustment feedback signal or current adjustment feedback data for the test signal source to adjust the amplitude of the first test signal until a preset test current at the output contact of the voltage regulator is achieved.
2. The test device according to claim 1 , further comprising a discharge stage connected to the output contact of the voltage regulator and operable to discharge load of an output capacity of the voltage regulator at its output contact at the beginning of the test.
3. The test device according to claim 1 , which test signal source is operable to provide a second test signal to simulate the load for the voltage regulator that causes the voltage regulator to change between different switching modes including at least one power save mode and an active or full power mode and which test device furthermore comprises a DC voltage stage connected to the output contact of the voltage regulator and operable to provide at an DC voltage stage output contact a voltage change feedback signal or voltage change feedback data for the test signal source to confirm compliance with the change between the at least one power save mode and the active or full power mode in response to the second test signal.
4. The test device according to claim 3 , wherein the DC voltage stage comprises a compensation type 2 network with an output contact connected to an input contact of a programmable gain controller, which is connected with its output contact to a direct input contact of a voltage follower stage, which provides at its output contact the voltage change feedback signal, which is fed to an A/D converter to provide the voltage change feedback data for the test signal source.
5. The test device according to claim 1 , wherein the test signal source is operable to provide a third test signal to simulate the load for the voltage regulator that causes the voltage regulator to change between the disconnected state of the switch to connected state of the switch with minimal variable drain-source resistance of the switch and the load resistor and the test device further comprising an AC voltage stage connected to the output contact of the voltage regulator and operable to provide at an AC voltage stage output contact a load change feedback signal or load change feedback data for the test signal source to confirm compliance with the change between the maximal load change in response to the third test signal.
6. The test device according to claim 1 , further comprising an oscillation damping feedback loop impedance connected between the switch driver output contact and the inverted input contact of the switch driver, which oscillation damping feedback loop impedance comprises at least one capacity and ohmic resistance connected in series to damp oscillations caused by an input capacity of the switch gate contact to avoid unwanted switching of the switch (Control loop I).
7. The test device according to claim 1 , wherein the switch is connected with its switch source contact via resistor to the switch driver inverted input contact (Control loop II).
8. The test device according to claim 3 , further comprising a controller configured to generate a switch signal or switch data for the voltage regulator to change the mode of the voltage regulator into an off state before running the test to confirm that the voltage change feedback signal or voltage change feedback data from the DC voltage stage indicate that the output voltage at the output contact of the voltage regulator is zero volt.
9. The test device according to claim 8 , wherein the controller is operable to generate a switch signal or switch data for the voltage regulator to change the mode of the voltage regulator into an on state before running the test to confirm that the voltage change feedback signal or voltage change feedback data from the DC voltage stage indicate that the output voltage at the output contact of the voltage regulator matches the voltage preset for this test.
10. The test device according to claim 5 , further comprising a controller operable to generate a switch signal or switch data for the voltage regulator to change the mode of the voltage regulator into an on state before running the test to confirm that the load change feedback signal or load change feedback data from the AC voltage stage indicate that no external noise is on the output contact of the voltage regulator.
11. A system comprising:
the test device according to claim 1 ; and
a computer operable to run a software to communicate with the test signal source of the test device and to display any of the following signals or data: first test signal; second test signal; third test signal; current adjustment feedback signal; current adjustment feedback data; voltage change feedback signal; voltage change feedback data; load change feedback signal; load change feedback data.
12. The test device according to claim 2 , wherein the test signal source is operable to provide a second test signal to simulate the load for the voltage regulator that causes the voltage regulator to change between different switching modes including at least one power save mode and an active or full power mode, and the test device further comprises an DC voltage stage connected to the output contact of the voltage regulator and operable to provide at a DC voltage stage output contact a voltage change feedback signal or voltage change feedback data for the test signal source to confirm compliance with the change between the at least one power save mode and the active or full power mode in response to the second test signal.
13. The test device according to claim 2 , wherein the test signal source is operable to provide a third test signal to simulate the load for the voltage regulator that causes the voltage regulator to change between the disconnected state of the switch to connected state of the switch with minimal variable drain-source resistance of the switch and the load resistor and the test device further comprises an AC voltage stage connected to the output contact of the voltage regulator and operable to provide at an AC voltage stage output contact a load change feedback signal or load change feedback data for the test signal source to confirm compliance with the change between the maximal load change in response to the third test signal.
14. The test device according to claim 3 , wherein the test signal source is operable to provide a third test signal to simulate the load for the voltage regulator that causes the voltage regulator to change between the disconnected state of the switch to connected state of the switch with minimal variable drain-source resistance of the switch and the load resistor and which test device furthermore comprises an AC voltage stage connected to the output contact of the voltage regulator and built to provide at an AC voltage stage output contact a load change feedback signal or load change feedback data for the test signal source to confirm compliance with the change between the maximal load change in response to the third test signal.
15. The test device according to claim 4 , wherein the test signal source is operable to provide a third test signal to simulate the load for the voltage regulator that causes the voltage regulator to change between the disconnected state of the switch to connected state of the switch with minimal variable drain-source resistance of the switch and the load resistor and which test device furthermore comprises an AC voltage stage connected to the output contact of the voltage regulator and built to provide at an AC voltage stage output contact a load change feedback signal or load change feedback data for the test signal source to confirm compliance with the change between the maximal load change in response to the third test signal.
16. The test device according to claim 2 , further comprising an oscillation damping feedback loop impedance connected between the switch driver output contact and the inverted input contact of the switch driver, and the oscillation damping feedback loop impedance comprises at least one capacity and ohmic resistance connected in series to damp oscillations caused by an input capacity of the switch gate contact to avoid unwanted switching of the switch (Control loop I).
17. The test device according to claim 3 , further comprising an oscillation damping feedback loop impedance connected between the switch driver output contact and the inverted input contact of the switch driver, and the oscillation damping feedback loop impedance comprises at least one capacity and ohmic resistance connected in series to damp oscillations caused by an input capacity of the switch gate contact to avoid unwanted switching of the switch (Control loop I).
18. The test device according to claim 4 , which furthermore comprises an oscillation damping feedback loop impedance connected between the switch driver output contact and the inverted input contact of the switch driver, and the oscillation damping feedback loop impedance comprises at least one capacity and ohmic resistance connected in series to damp oscillations caused by an input capacity of the switch gate contact to avoid unwanted switching of the switch (Control loop I).