To make portable devices more efficient, engineers have devised clever power-management circuits and software. Mobile devices can turn up the power just when needed and return to sleep mode when idle. But, measuring peak-power consumption can be difficult because power is fully on for short intervals. Plus, the standby current can be 20-to-30 times less than operating current.
Keithley Instruments addresses the issue with the 2280S series of power supplies. The series consists of two models: 32 V, 6 A and 60 V, 3.3.A, both priced at $1990. In addition to being a programmable power supply, the 2280S contains a 6½:-digit digital multimeter (DMM) that’s fast enough to measure power consumption on pulses as narrow as 140 µs. The figure below shows that you can trigger a measurement based on a rise in current.
The power supply uses a linear topology, which means it won’t add switching noise to your system. The power source has 10 µV sensitivity and the meter has 100-nV measurement resolution. In addition to being a DMM, the 2280S can log data for downloading and its icon-based display can show voltage and current in graphical form. You can control the instrument through its LXI LAN port, USB port, and GPIB port. When using LAN port, the 2280S’s LXI compliance lets you control it through a browser.
In addition to having communications ports, the 2280S has a terminal strip in the rear panel (see photo below). That lets you run four wires to the device under test, providing remote sensing so you’re measuring voltage right at the DUT. The rear panel also contains a TTL-level I/O port that adds an external trigger for measurements or a digital signal to an automated production test system indicating that it’s ready to proceed.
Comments are closed.
