NXP Semiconductors AN11524, Application Note, Page: 6 / 54

AN11524 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2015. All rights reserved.
Application note Rev. 1 — 17 February 2015 6 of 54
NXP Semiconductors
AN11524
NXQ1TXA6 Evaluation Board
3.2 Main features
The NXQ1TXA6 Evaluation Board demonstrates:
•
A reference design with key components from NXP for wireless charging applications
based on inductive power transfer standard Qi.
•
Shows additional benefits resulting from integration of NFC with wireless charging.
Enabling for example zero power standby with the “tap to power on” feature.
3.3 System efficiency
In Figure 3 , the system efficiency of the evaluation board is shown using a standard off the
shelf receiver.
System efficiency is measured as the ratio of output power of the receiver to the input
power of the transmitter. Input power is averaged to take into account variation due to
communication between receiver and transmitter.
The quality of the components used in both the transmitter and the receiver, determine the
efficiency of the system.
3.4 Board overview
The evaluation board is shown in Figure 4 . The left-hand side contains the charging area
where the mobile device should be placed. The top right side has the electronics to drive
the charging coil and communicate with the mobile device.
(1) outer coil 1
(2) center coil
(3) outer coil 2
Fig 3. System efficiency
output power (mW)
0 5,000 4,000 2,000 3,000 1,000
aaa-015880
40
20
60
80
η
(%)
0
(1)
(2)
(3)