AATIAN22 Datasheet, PDF (8/11 Pages) SiGe Semiconductor, Inc. – 3MHz Fast Transient 400mA Step-Down Converter

EV-139
AAT1149 EVAL: 3MHz Fast Transient
400mA Step-Down Converter
Test: Efficiency vs. Output Current
1. Configure the specified test equipment as shown in Figure 7. Connect voltmeters as closely as possible
to the input and output capacitors to avoid voltage drop along the trace resistance.
2. Enable UUT by connecting the jumper to the “ON” position.
3. Set Keithley load to 4 Wire Sensing Mode (the two sensing wires should connect as closely as possible to
the output cap.
4. Vary the output current (I_OUT = I_SRC) from -1mA to -400mA and keep the input voltage the same while mon-
itoring the input current (I_IN), and the output voltage (V_OUT).
5. Calculate the efficiency as the following equation:
Efficiency
=
η%
=
100
·
(V_OUTI_OUT)
V_INI_IN
6. Repeat steps 4 and 5 for different input and output voltages.
Figure 7: AAT1149 Evaluation Board Connection Diagram for Efficiency vs. Load Current.
8
EV-139.2007.08.1.0