The Keithley 2281S-20-6 20V/6A Precision DC Supply/Battery Simulator innovatively integrates battery simulation with the functions of high-precision power supply and battery testing. It is able to analyze the DC consumption of a device under test, test a battery, generate a battery model based on battery charging processes, and simulate a battery based on the battery model. The 2281S-20-6 can output power up to 20V and 6A, and sync current up to 1A.

The 2281S-20-6 uses linear regulation to ensure low-output noise and superior load current measurement sensitivity. A high resolution color Thin Film Transistor (TFT) screen displays a wide range of information on measurements. Soft-key buttons and a navigation wheel combine with the TFT display to provide an easy-to-navigate user interface that accelerates instrument setup and operation. In addition, built-in plotting functions allow monitoring trends such as drift. These features provide the flexibility required for both benchtop and automated test system applications. In addition, the 2281S-20-6 provides a list mode, triggers, and other speed optimization functions to minimize test time in automated testing applications.

Figure 1. Series 2281S startup screen

Figure 2. Battery simulator home screen

Figure 3. Graph of Voc, ESR, and SOC

Battery Simulation Based on a Battery Model

In the battery simulator function of the 2281S-20-6, real battery output performance can be simulated based on a selected battery model. State of Charge (SOC) and Voltage Open Circuit (Voc) can be set to any state to test the device under specific circumstance. There are two modes from which to choose:

Static: During the static simulation, Voc and SOC stay the same.

Dynamic: During the dynamic simulation, Voc and SOC change according to charging and discharging as with a real battery. Capacity can also be reduced to accelerate the charging and discharging process for better test efficiency.

Determine SOC and ESR and Create a Battery Model During Battery Testing

The 2281S-20-6 battery test function tests the charge/discharge of a battery. Charging current ranges from 0 to 6A; maximum discharging current is 1A. During the charging, the sampling interval can be set for the internal 6 1/2-digit multimeter to sample the charging current and voltage continuously. In this way, the capacity of the battery and its internal resistance (ESR value) are automatically computed.

After the test, a battery model can be generated based on the measurement result of the battery charging process. A battery model can be edited, created, imported, or exported in a CSV file format.

Easily View and Control Every Parameter of the Battery Test and Simulation Function

The bright, 4.3-inch TFT display shows voltage, current, and amp-hour readings, source settings, and many additional settings in large, easy-to-read characters. The icon-based main menu provides all of the functions users need to control and program for fast access to source setup, measurement setup, display formats, trigger options, and system settings. Menus are short and its options are easy to find and are clearly described; this enables test parameters to be setup quickly by using the navigation wheel, keypad, or soft-keys. Many setup parameters, such as voltage and current settings, can be entered directly from the home screen; less complex tests do nor require access to the main menu to make adjustments - just use soft keys on the home screen. Whether test requirements are simple or complex, the 2281S-20-6 provides a simple way to set up all required parameters.

Figure 4. Battery test display

Figure 5. Battery model

Figure 6. Battery test menu

Optimized Performance for Production Test

The 2281S-20-6 is as powerful in a production test system as it is flexible on the R&D benchtop. It provides SCPI commands for all measurement functions. In addition, several other features can help minimize test time in automated systems. For example, an external trigger input allows hardware synchronization and control by other instruments in the test system. For the battery test and battery simulator function, the digital I/O can be configured as input or output. If the digital I/O is configured as input, the measurement can be triggered by external signals; if the digital I/O is configured as output, the digital I/O pin will send out a signal when the measurement is finished. Furthermore, to reduce measurement time, reading speed can be increased by reducing the acquisition time from 16.6ms (or 20ms) to 33μs (40μs).

A choice of front or rear panel terminals provides enhanced connection flexibility. For maximum voltage accuracy, 4-wire remote sensing ensures that the output voltage programmed is actually the level applied to the load. In addition, the sense lines are monitored in order to detect any breaks in them. These features ensure that any production problems can be quickly identified and corrected. The 2281S-20-6 can be controlled via its built-in GPIB, USB, or LAN interfaces. The USB interface is test and measurement system (TMC) compliant. The LXI Core compliant LAN interface supports controlling and monitoring a 2281S-20-6 power supply remotely, so test engineers can always access the power supply and view measurements, even if located on a different continent than the test systems.

Precision DC Power Supply with DMM-Quality High-Resolution/Low-Current Measurements Capability

The 2281S-20-6 features up to 120W, 20V, and 6A output and can also make measurements with up to 6 1/2 digits of resolution. Voltage output measurements can be resolved down to 100μV. These supplies measure load currents from 100nA to amps. Four load current measurement ranges (10A, 1A, 100mA, and 10mA) support measuring a device's full load current, standby mode current, and small sleep mode current with DMM-quality accuracy. The high resolution allows discerning small changes in load currents with confidence. It also makes it possible to make a broad range of measurements or a single range with excellent accuracy across both low and high current values.