User Guide Rev 2.0
www.semtech.com
6 of27
TSDMTX-19V3-EVM
May-18
Semtech
EVM Receiver Tests
Additional testing can be performed with the use of an EVM receiver module. There are a number of Semtech
Receiver EVMs that support different power levels and output voltages, any of which can be used, as all support
the Qi standard and therefore are compatible with the TSDMTX-19V3-EVM transmitter. In this User Guide, the
TSDMRX-19V/20W-EVM has been selected as the receiver to experiment with. Other Semtech receiver EVMs
may be used instead in a similar manner; refer to the user guide for the selected receiver for details specific to the
selected device. Also, you can use phones which includes WPC wireless charging functions, like Samung phone S6
or above and Iphone 8 or above, to test TSDMTX-19V3-EVM.
In order to use the TSDMRX-19V/20W-EVM as a target receiver, simply place the receiver over the target circle on
the transmitter EVM module. You should see the LEDs on each EVM turn green, indicating a transaction has been
established. The EVM’s purpose is to receive power; next you can decide what to deliver that power to.
The user has a number of possible options to choose from. The optimal load to select would be a Programmable
DC Electronic Load. A ‘load box’ can easily be set to draw a selected current or power at the turn of a knob,
making them very flexible and easy to use in observing power supply operation in general. If a load box is not
available, a power resistor decade box is nearly as convenient, as it can easily be set to any desired resistance to
simulate a range of load conditions. In either case, please make sure the test load is rated for at least the amount
of power being tested. If need be, a selection of power resistors could be used as test loads, though without the
ease of modification of the prior options. Finally, any device that uses a 19 volt input up to 15 watts of power can
be used as a desired test load.
Whatever load is selected, wires must be run from the VOUT+ and GND pins of the receiver EVM to the selected
test load, as per the illustration below. Once the load is added, the receiver EVM can be used to perform a variety
of tests. Alternately, power can be drawn from the VBUS and GND lines of the USB port if desired.
Connect a DC voltmeter across the VOUT+ and GND pins to monitor the voltage being output to the load, and a
DC ammeter in series with the VOUT+ line. Set rating of those meters to allow for up to 19 volts and 1.1 amps to
be observed.
