Agilent HP AN 1310 Application Note free download

File name HP AN 1310 Application Note.pdf

Agilent AN 1310 Mobile Communications Device Testing Application Note Considerations when selecting a System Power Supply for Mobile Communications Device Testing Abstract Pulsed battery drain currents, reg- ulated charge currents, and remote DUT (Device Under Test) fixtures, dictate the need for specialized power sourcing, loading, and meas- urement capabilities for testing mobile communications devices. Many of these capabilities are not available in general-purpose system power supplies. This guide will assist the test sys- tem designer in selecting a system power supply by properly evaluat- ing test system and power supply needs that are unique to the appli- cation and not immediately obvi- ous. In this way, many problems likely to arise in production can be avoided. Overview Mobile Communications System Power Supplies The growth of the mobile communica- In the production testing of mobile Section One tions market is clearly in the newer communications products, a system Considerations when Sourcing Power to digital wireless products. The con- power supply replaces the battery. the DUT sumer advantages are significant-- High volume manufacturing often dic- A. Transient Voltage Drop at the DUT improved transmission quality, acces- tates that the DUT fixture is remotely Fixture sibility, security, and operating time. located from the test system, intro- ducing significant impedance due to B. Pulsed Current Sourcing for DUT Digital mobile communications long wiring length. This, in combina- Transmit Burst Current Drain devices transmit in short bursts tion with pulsed current drain, makes which conserves power between it challenging to maintain a stable, Section Two transmissions, thus extending talk transient-free voltage at the fixture Considerations when Loading the DUT time of the battery. Likewise, during just as if the DUT were operating Battery Charger standby, some digital devices also directly from a battery. In addition to A. Constant Voltage Loading "wake up" and listen for incoming emulating the battery, the