ZS1100A : Performance Data
Accuracy measurement (Static)
The accuracy is measured by connecting a known load at the output and measuring it with the ZS1100A. The output is a static load (resistor) and the current is measured with averaging. Observe the very low error rate across the whole range. This is possible due to the usage of precision components. The dynamic error is no different from the static error as a SAR ADC is used in this tool. Using a Delta Sigma ADC to achieve high dynamic range is a cheaper option, but those can suffer from accuracy with fast moving inputs.
Capacitor charging
This current waveform is measured by connecting an RC circuits at the output of the ZS1100A and turning ON the outputs. The capacitor charges through the resistor and the classic exponential curve is captured here. Notice the smooth waveform which is possible by advanced noise reduction techniques.
Capacitor discharging
This current waveform is measured by connecting an RC circuits at the output of the ZS1100A and turning OFF the outputs. The capacitor discharges through the resistor and the classic exponential curve is captured here. This demonstrates the negative current measurement capability of the tool.
Dynamic Range
This current waveform is measured by connecting a ESP8266 module to the ZS1100A. The module is initially in sleep mode while consuming about 15uA. Then it enters IDLE state with few 10mA. After a while it performs a power amp calibration which is indicated by the peaks reaching 350mA. The output voltage is set to 3.0V and under all these load conditions, the output remains fairly stable. This is possible by the supply and ground sensing loops in the design.
Capture Span
The long capture time of the ZS1100A is helpful in observing sleep behaviour of IOT devices. The tool can capture data for several hours long. Shown above is a 80 second window captured from a WiFi module.
Calibration cycle
The plot shows the complete calibration cycle of the ESP8266 module. Notice how the profile gives out information about the power amplifier calibration process. We can clearly distinguish the Power amplifier being cycled across various power levels and frequencies.
Filament bulb turn-on
The plot shows the current profile of a filament bulb as it gets turned ON. Notice the initial peak current when the filament is cold and the resistance is low. After several milli -seconds, the filament heats up and the current reaches steady state. This plot is measured by connecting a filament bulb across the outputs and then enabling the outputs. Notice the smooth current waveform, which is possible due to advanced noise reduction and linearization techniques.
Step Response
The plot shows the step response of the tool while capturing the current profile of a WiFi module. Note the sharp rise time and fall times which are several micro seconds wide. The total pulse is less than 1 ms wide and the tool is able to capture the pulse in great detail and accuracy.
Transfer function
The plot shows the transfer function of the measurement. Notice the excellent linearity of the tool, which also extends to the negative direction with current up to -0.5A. This is possible due to careful design of the front end and the ADC driver stages.