Multi-channel probing systems aids power supply optimisation in wireless devices

March 17, 2017 // By Graham Prophet
Rohde & Schwarz’ RT-ZVC02/04 multichannel power probe can measure across large current and voltage ranges without having to switch ranges, making it possible to monitor the power consumption of chipsets, radio modules and wearables.

When used in combination with an R&S RTE or R&S RTO oscilloscope, the current drain can be correlated with analogue and digital control signals, enabling developers to optimize the battery life of wearables and wireless devices early in the development cycle.

 

Typically, such products operate at low standby current with very brief periods of activity when higher currents are needed. An unusually wide dynamic range is required to determine the true power consumption. Multiple test channels are often needed since different electronic circuit modules are activated at different times. The multichannel power probe addresses this application by permitting simultaneous measurement of up to four currents and four voltages over a very wide dynamic range. The measured values are transmitted to the R&S RTE or R&S RTO oscilloscope via the digital logic interface and then displayed synchronized with the oscilloscope's analogue channels. A trigger unit integrated into the power probe enables triggering on the R&S RT-ZVC input signals.

The probe contains an 18 bit A/D converter for each current or voltage measurement channel. This makes it possible to measure very low standby currents in the µA or nA range as well as high current peaks up to the Ampere range within the selected current measurement range without having to switch ranges. With 1 MHz bandwidth and a sampling rate of 5 Msample/sec, very brief current pulses can be captured so that the true power consumption can be correctly determined. Three selectable internal shunts allow the user to select the optimal current range. An external shunt can be used for user-specific current measurement ranges or when the current needs to be measured as close to the DUT as possible.

 

The RT-ZVC02 power probe has two current and two voltage channels, the R&S RT-ZVC04 four current and four voltage channels in addition to the analogue oscilloscope channels. One or two RT-ZVC02/04 probes can be connected to an R&S RTE or