Application Note 138
October 2013
Wireless Power User Guide
Trevor Barcelo OVERVIEW
An inductive wireless power system consists of a transmitter that generates a high frequency alternating magnetic
field and a receiver that collects power from that field.
The resonant coupled system described here provides for
increased power transmit distance and reduced alignment
sensitivity, with no need for a coupling core. To build a wireless power system four items are required:
transmitter electronics, transmit coil, receive coil and
receiver electronics. The LTC4120 wireless synchronous
buck charger combined with minimal external circuitry
comprises the receiver electronics (Figure 1). Please see
the LTC4120 product page for more details including the
data sheet and demo board design files.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners. Figure 1. LTC4120 Receiver Demo Board (Rx Portion of DC1969A Kit) an138fc AN138-1 Application Note 138 Figure 2. Implementation of Basic Transmitter Reference Design (Tx Portion of DC1969A Kit) Figure 3. Proxi-Point Transmitter Figure 4. Proxi-2D Transmitter an138fc AN138-2 Application Note 138
Transmitter Solutions BASIC TRANSMITTER Currently there are four transmitter options available for
design or off-the-shelf purchase: The basic transmitter for the LTC4120, described in the
following sections, combined with a receive coil and
LTC4120-based receiver electronics can be used to
produce a wireless battery charging system. This wireless battery charging system enables evaluation of the
LTC4120 using standard components. 1. Basic: This wireless power design (Figure 2) was …