Dual-Channel Power Supply Optimized for Testing Portable Battery-Powered Devices

Unlike conventional power supplies, the Model 2308 features extremely fast recovery even when load currents change by a factor of 10 or greater. This can happen when a portable device or component transitions near-instantaneously from a sleep or standby state to a full power operating state and then returns to the original state. If the load pulse is too short, the conventional power supply may never return to its stable output level during the pulse. Even with long test leads, which add substantial inductance to the load circuit between the power supply and the device under test (DUT), the Model 2308 maintains a stable output voltage in response to pulse loads with a transient voltage drop of under 90mV and a transient recovery time of under 35µs. This is critical for mobile phones with pulsed-mode operation such as new EDGE, WiMAX, and future LTE mobile devices. Maintaining a constant output voltage ensures that the DUT does not turn off during testing and that it draws sufficient power to operate properly, thus avoiding false failures due to inadequate sourcing. Furthermore, an excessive overshoot voltage transient can damage components leading to premature device failures. The unique, specialized, Model 2308 has the fast transient response essential for maximizing production yield and product quality by preventing false failures related to conventional sourcing, which cannot provide the high speed response necessary to maintain a constant output under fast-changing loads.
Fast and High Resolution Load Current Measurements for Reduced Test Times and Higher Quality Control

The Model 2308 also saves valuable test time by making fast load current measurements. An optimized command structure minimizes range changes and current measurement times for production testing. The Model 2308 can change range and make a power line cycle measurement in a market-leading 27ms. With four current ranges spanning 5A to 5mA, and resolutions from 100µA to 0.1µA, test engineers can monitor small changes in load current measurements for tight quality control on production runs. Furthermore, load currents, even pulses as narrow as 50µs, are measured with integrating A/D technology. An integrating A/D, by continuously acquiring the signal rather than capturing discrete samples, provides a more accurate measurement than other A/D techniques. With a sampling A/D, information between samples is lost, which reduces the accuracy of the overall measurement. In addition, the lower noise inherent in integrating A/D converters generates the most stable current readings. The Model 2308 combines outstanding speed with high quality measurements.
Flexible and Adaptable for Research & Development as Well as Production Test

The Model 2308 features functionality that makes it suitable both for production test as well as research and development (R&D). In production applications, the Model 2308 employs four-wire sourcing and remote sensing for precision voltage sourcing even when the DUT cannot be close to the power supply. The superior source accuracy enables a Model 2308 channel to act as a calibration source for battery monitoring circuitry used in mobile phones and other portable devices. With two channels packed into one half-rack instrument, one channel can simulate the battery and the other can simulate a charger. In addition, each channel can act as a load as well as a source. Thus, the battery channel can sink current to simulate a discharged battery so that the DUT’s charger control circuit can be tested. For R&D applications, the Model 2308 not only has wide current measurement range for analyzing power consumption, the power supply also has an analog output to enable developers to analyze all the details of their load current including the start-up sequence and all operating modes. Thus, R&D engineers can easily determine total device power consumption. In addition, the Model 2308 can simulate the performance of a battery by simulating the battery’s internal resistance with a programmable output resistance. Similar to a battery, the Model 2308’s output resistance can change while voltage is being sourced to simulate the increase in the battery’s internal resistance as the battery discharges. Thus designers can determine how their device will perform when powered by what will look like the actual source.

The Model 2308 contains two power supply channels, a DVM for voltage measurements on the DUT and digital control ports for relay control. The total package combines a number of instruments needed in production and saves valuable bench space in the R&D lab.
Tests a Wide Range of Products

The Model 2308 is particularly well-suited for design and test of low-power, battery-operated devices, such as 3G mobile phones, smart phones, MP3 players, Bluetooth headsets, PDAs, and portable GPS receivers. The Model 2308 is also optimized for components and sub-systems, such as baseband/power control chipsets, RF power amplifiers, RF power transistors, transmitters, and transceivers.