Agilent B2901/02/11/12A Precision Source/Measure Unit How to make a sampling measurement with pulsed source This material shows how to perform a sampling measurement through an example of sourcing the pulsed current to LED and measuring the voltage. Figure 1 illustrates the connection and condition supposed in the example of measuring LED using the B2901/02/11/12A. B2901/02/11/12A A V High Force DUT - Low Force Figure 1. Connection and condition supposed in the example Figure 2 shows the timing chart for the sampling measurement with pulsed source with the front panel operation. In this case, the specified source value is sourced immediately after turning on . Then, when you press , the instrument will make a sampling measurement. Pulse parameters will be used in the example in order to source the pulsed current. Besides, if it is necessary, you can specify any measurement trigger delay time which is the wait time after each internal trigger and before making a measurement. If you configure the pulsed source, the measurement will be made with FIXED measurement range operation automatically. The measurement range is selected by Limit value. The measurement time consists of Measurement Speed and some overhead time. Measurement Speed is the parameter specified by the user. Overhead time includes the time to change the measurement range, etc. TP V or I TP TP TP TP TMD TMD TP TP TMD Pulse Peak Value TMD TMD Source Value TM Output Off State TM TMD TM TPD Trigger Output ON TM Internal Trigger TM TMD TM TPW TM :Measurement Time TPD : Pulse Delay TMD : Measurement Trigger Delay Time TPW : Pulse Width TP : Trigger Period TM : Measurement Time Figure 2. Timing chart for the sampling measurement with pulsed source Agilent B2901/02/11/12A Precision Source/Measure Unit Performing a sampling measurement Step 1. Press Step 2. Press source. repeatedly until Single View for Channel 1 is shown in the display. to edit the source function, and then select (1) Press Mode Step 3. Press Press (2) Press AMPS (I) to edit the source value, and then enter 10 nA to set the source value to 10 nA. (1) Press Source Step 4. to set the source function to the current (2) Enter Source Value to edit the limit value, and then enter 2 V to set the limit value to 2 V. (1) Press Limit (2) Enter Limit Value Step 5. Press to configure the measurement parameter, and then select parameter to the voltage. (1) Press Measure (2) Press VOLTS (V) to set the measurement Agilent B2901/02/11/12A Precision Source/Measure Unit Step 6. Press to change the keys shown in Assist keys, and then press (1) Press Show Pulse Step 7. Press , then press (2) Pulse Sub-Panel appears to set the pulse source ON. After turning on the pulse source, you can see Source Shape which shows the pulse source mode. (1) Press ON Step 8. Rotate Source Shape to select Channel 1 Pulse Parameters and set them up as below. (Peak: 10 mA, Delay: 20 ms, Width: 60 ms) to show Pulse Sub-Panel. Agilent B2901/02/11/12A Precision Source/Measure Unit Step 9. Press to show Trigger Sub-Panel. (1) Press Show Trigger Step 10. Press to edit the trigger type, and then select (1) Press Step 11. Rotate (2) Trigger Sub-Panel appears to set the trigger type to TIMER. (2) Press TIMER to select Channel 1 Trigger Parameters and set them up as below. Measurement Trigger Count defines the number of sampling and Measurement Trigger Period defines the interval of sampling. (Source Trigger Count: 1, Measurement Trigger Count: 101, Measurement Trigger Delay Time: 500 us, Measurement Trigger Period: 1 ms) Now you’ve configured 1 ms measurement trigger period for a sampling measurement. The measurement will be performed every 1 ms periodically. However, please note that FIXED current measurement range operation will be used to control the trigger period strictly. The measurement range is selected by Limit value. In this example, 2 V measurement range will be used. Agilent B2901/02/11/12A Precision Source/Measure Unit Step 12. Press repeatedly until Graph View is shown in the display. Step 13. Rotate and press to edit the Y-axis data type, and then select to set the Y-axis data type to the voltage. (1) Rotate and press Y-axis Data Type field Step 14. Rotate and press (1) Rotate Type field Step 15. Press to select (2) Press VOLTS (V) to edit the X-axis data type to select X-axis Data , and then select (1) Press More … (2) Press Type to select X-axis Data to set the X-axis data type to the time. (2) Press TIME (t) Step 16. Press to source the current, and then press (The status information will show during the measurement.) to perform a measurement. Agilent B2901/02/11/12A Precision Source/Measure Unit Step 17. Press to adjust the scale of the graph after finishing the measurement. Step 18. Rotate and press (1) Rotate and press Y-axis scaling to edit the Y-axis scaling, and then enter 2 V to adjust the graph scale. to select (2) Enter the scale such as 2 V Now you can see the measurement result on the GUI of the B2901/02/11/12A as bellow. Agilent B2901/02/11/12A Precision Source/Measure Unit Configuring the measurement speed In the default setting, the instrument selects the appropriate measurement speed automatically to get the fine accuracy. However, you can also specify it on the GUI of the B2901/02/11/12A to meet a variety of the requirement to the measurement conditions. For example, let’s try to change the measurement speed to SHORT to make a measurement more quickly. If you select SHORT, the aperture time is set to 0.01 PLC. Here, PLC stands for power line cycle and the specified number of power line cycles is used per a measurement. Step 1. Press Step 2. Press repeatedly until Single View for Channel 1 is shown in the display. to edit the measurement speed, and then select SHORT. (If you can’t see in Assist keys, press (1) Press Speed to set the measurement speed to to change the keys shown in Assist keys.) (2) Press SHORT Viewing the list of measurement results The measurement results including the measurement time stamp can be referred by the following steps. Step 1. Step 2. If you aren’t on the top of the Function menu, press repeatedly to return to the top level. On the top level of the Function menu Any tree structure can’t be seen In the middle level of the Function menu Some tree structure can be seen If you’d like to see the list of the measurement result, press , then press Measure Result dialogue. (1) Press Result (2) Press Measure to open Agilent B2901/02/11/12A Precision Source/Measure Unit Step 3. Rotate and press (1) Rotate field Step 4. Press type. to select Data Type field. to select Data Type To select Data Type to change the keys shown in Assist keys, and then press (1) Press More … Step 5. (2) Press Rotate and press (1) Rotate and press Data field to select Time as the data (2) Press TIME (t) to select Data field. Then rotate to select to scroll the data list. (2) Rotate or press Assist key to scroll the list