B8 Current profiler

What it is

B8 is a current and energy profiler for anything that runs on a battery. Put it in line with a device and it records the current through sleep, wake-up and transmit, while marker inputs from your firmware tie each burst to the code that caused it. Battery life stops being an estimate: it's the measured charge per cycle.

It can also power the device under test itself, so one card is the supply and the meter.

Capabilities

Design values and targets. Measured values replace these after bring-up.

• Three fast ranges: 0–4.36 mA, 0–436 mA and 0–10.24 A (target), plus a sleep range down to nanoamps (target).
• About a million samples a second in Slot B (design), with about 200 kHz of bandwidth (target).
• Devices up to 48 V (target).
• A built-in supply for the device under test, 0 to about 20 V at 1 A (target), and battery emulation (target).
• A 3-bit marker input that tags the trace from your firmware.
• 4 mm jacks. Not isolated.

Build with it

• Transient current profiler. B8 leads, with A7 alongside and an FP1 front panel.
• TEC source-measure, cooling only. B8 and a C4 cover the case that doesn't need four quadrants.

Calibration

B8 is calibrated against a 10 V reference, a 10 kΩ standard resistor and a power resistor of about 100 Ω for the amps end. How calibration works