The Keithley 2302 Battery Simulator was designed specifically for development and test applications of portable, battery-operated products, such as cellular and cordless telephones, mobile radios, and pagers. This precision power supply has an ultrafast, transient response, so it can have output characteristics identical to actual batteries. The 2302 employs a unique variable output resistance so the voltage output can emulate a battery's response (U.S. Patent No. 6,204,647). It provides stable voltage outputs, even when a device-under-test (DUT) makes the rapid transition from the standby (low-current) state, to the RF transmission (high-current) state. In addition, it can monitor DUT power consumption by measuring both DC currents and pulse load currents. The Model 2302's battery-simulator channel can be programmed to operate like a discharged rechargeable battery.

Maximize Test Throughput with Accurate Battery Simulation

The battery-output channels of the Models 2302 are designed to simulate the output response of a battery. This capability, combined with its fast transient response, makes it possible to power the device during testing in exactly the same way as a battery will power the device during actual use. The output resistance of the Model 2302's battery channel can be programmed (with 10mW resolution) from 0W-1W, so that the output resistance can be set to the same level as the output resistance of the battery that powers the device.

Portable wireless devices make great demands on their battery power sources. The battery must source load currents that can jump almost instantaneously from a standby current level (100–300mA) to a full-power RF transmission current level (1–3A). In other words, the load current on the battery can increase rapidly by a factor of 700–1000%. As a result, the battery voltage drops by an amount equal to the value of the current change multiplied by the battery's internal resistance. The 2302 power supplies enable test systems to duplicate this voltage drop by programming their output resistance to be equivalent to that of the battery that will power the device. This allows wireless device manufacturers to test their products under the same power conditions that they will encounter in actual use.

In response to large load changes, the 2302 has transient voltage droops of less than 100mV and transient recovery times of less than 60μs, even when the test leads between the power supply and the DUT are long. This fast transient response, combined with the supply's variable output resistance, allows engineers to test their portable products under the most realistic operating conditions and eliminate false failures due to conventional power supplies with slow response times. These supplies also eliminate the large stabilizing capacitors needed at the DUT to compensate for the large droop that occurs when testing with conventional power supplies. By varying the output resistance, which can be done while the output is turned on, test engineers can simulate the operation of different battery types, as well as batteries nearing the end of their useful lives.

The 2302 ensures maximum production throughput when testing portable devices by minimizing false failures, minimizing the number of test setups by performing multiple tests with the same power supply, and minimizing test fixture complexity by eliminating the need for voltage-stabilizing capacitors.

Measure Load Currents for Power Consumption Verification or Analysis

As manufacturers of portable devices strive to extend their products' battery life, measuring load currents accurately has become increasingly essential in both design and production testing in order to ensure the product meets its demanding specifications. Comprehensive testing of these devices requires measuring peak currents, average currents, and baseline currents in various operation modes. When testing these devices, these measurements are complicated by the pulsating nature of load currents, such as the transmit and receive load currents of digital cellular phones. The 2302 can measure the peak and average currents of pulses as short as 60μs and as long as 833ms.

Measure Long-Period Waveform Currents

For pulse trains with periods longer than 850ms, the 2302 offers a unique, long integration current measurement mode. This mode can provide an average measurement of a current waveform from 850ms, up to 60 seconds long.

Measure Low-Currents Accurately

The 2302 is based on Keithley's expertise in low-current measurement technologies, so it is well-suited for making fast, accurate measurements of sleep and standby mode currents. With 100nA resolution and 0.2% basic accuracy, it provides the precision necessary to monitor the low sleep mode currents of both today and tomorrow's battery-operated products.

Verify Load Currents in All Operating States

The 2302 employs a unique pulse current step function for measuring the load current at each level of a device's operational states. For example, if a cellular phone is ramped up and down through as many as 20 discrete power consumption states, the 2302 can measure the load currents in synchronization with the current steps. This capability allows a test engineer to verify performance at each operational state and simultaneously acquire power consumption information. The fast current measure capability is another way the Models 2302 saves test time and production costs.

Simulate a Discharged Battery for Charger Testing

The 2302 can sync up to 3A continuously, just like an electronic load. This allows these supplies to simulate a discharged rechargeable battery for use in testing the performance of battery chargers, or battery charger control circuitry.

Open-Sense Lead Detection

The 2302 has an automatic open–sense lead detection capability, which indicates if there is a broken remote sense lead or an open connection from a remote sense lead to the test fixture. To ensure the output voltage does not change from the programmed level, which could cause production devices to be improperly calibrated, the user can set high and low limits around the desired voltage level.

Independent Digital Voltmeter Inputs

Many programmable power supplies offer output readback capabilities, but the 2302 also offers DVM inputs. It allows measuring signals from -5V to +30V DC anywhere in the test system with the same rated accuracy as the voltage readback. The DVMs and the power sources can operate simultaneously. For many applications, these built-in DVMs eliminate the expense and space required to add a separate voltage measurement instrument.

Big Functionality in a Small Package

The 2302 provides extensive measurement capabilities in the same halfrack case. The front panel of each unit displays the user's choice of either the output voltage and output current, the average, tje peak, and the baseline pulse current levels, long integration currents, or DC DVM measurements. A minimum of front panel buttons ensure that operation is simple and straightforward.