The UCC14141EVM-068 EVM uses screw
terminals for quickly connecting to the VIN, VDD ,and VEE pins.
Connecting the appropriate ammeters and voltmeters, as shown in Figure 4-1, allows accurate EVM efficiency measurements to be made.
Connecting Test
Equipment
- Move jumper SH-J1 into the J2:1-2, EN OFF
position. This makes sure the EVM cannot start while test equipment is being
connected.
- Connect a +5 V DC bias power
supply to J1:1-2 (+3.3 V to +5 V). Set the power supply to 0 V. The +5 V supply
at J1 serves as the pullup bias for /PG and ENA. Turn off/disable the +5V DC
Bias power supply.
- Connect the VIN DC power supply
capable of 8 V<VIN<18 V, 300 mA at J4:1-2 (VIN).
Adjust the power supply to 12 V, and set the current limit to 300 mA. Set the
power supply voltage to 12 V. Turn off/disable the VIN power
supply.
- Connect a variable load between J3:1 (VDD) and
J3:3 (VEE). If using an electronic load, set to constant current (CC), 68 mA.
Leave the load disabled until the EVM is powered.
- Connect a second load between J3:2 (COM) and J3:3
(VEE). If using an electronic load, set to constant current (CC), 10 mA. Leave
the load disabled until the EVM is powered. Since the required load is small, a
through-hole, 250-mW, 400-Ω load resistor can be connected between J3:2-3.
- Some electronic loads are not be able to
regulate/stabilize CC when setting in the low mA range. Monitor the input
current and load currents by inserting ammeters, A1-A3, as shown in Figure 4-1. Use a current probe with the oscilloscope to verify the stability of the DC
current being regulated by an electronic load.