Instructions

In this section:
Introduction .............................................................................. 9-1
Equipment required .................................................................. 9-2
Device connections .................................................................. 9-2
Measuring power using digitizing and TSP-Link ....................... 9-4
Introduction
This application example demonstrates how to configure two DMM6500 instruments to use TSP-Link
®
to measure the power consumed by a Bluetooth
®
low-energy (BLE) device.
For this example, one DMM6500 measures digitized voltage while the other instrument measures
digitized current. Using TSP-Link, these measurements are made simultaneously and the results
communicated between the two instruments. Using TSP scripting, the average power consumption
during the test period is calculated using the following formula in which P
ave
is the average power and
n is the number of points.
This application example calculates power at each point along the waveform by multiplying
corresponding currents and voltages, adding them together, and dividing them by the total number of
data points to find the average power usage.
Average power measurements provide insight into device performance. This is more accurate than
multiplying the average current by the average voltage to find average power.
Some applications calculate power by measuring current measurements and then multiplying them by
the known battery voltage. The advantage of digitizing both current and voltage simultaneously is
increased accuracy, because the exact voltage is known at each current measurement.
These measurements are especially important when the device under test (DUT) requires a battery to
operate, because minimizing power consumption maximizes battery life.
Section 9
Measuring power using digitizing and TSP-Link