DEMO MANUAL DC2554A-A-KIT/DC2554A-B-KIT LTC4125 and LT3652HV 650mA Wireless Battery Charger Demonstration Kit DESCRIPTION DC2554A-KIT is a kit of the DC2556A transmitter, and receive coils. The DC2556A transmitter supports featuring LTC 4125, the DC2555A-A/DC2555A-B receiver, Optimum Power Search and Foreign Object Detection featuring LT3652HV. The DC2555A-A/DC2555A-B receiver features via LTC4125. can charge a single Li-Ion battery at up to 650mA with Design files for this circuit board are available. an air gap of 3.0mm to 12.0mm between the transmit All registered trademarks and trademarks are the property of their respective owners. CONTENTS 1 DC2556A (LTC4125) Transmitter Demo Board 1 DC2555A-A/DC2555A-B (LT3652HV) Receiver Demo Board (with 9.5mm (0.375) Nylon Standoffs, 5.25mm Gap) 4 12.5mm (0.375) Nylon Standoffs (8.25mm Gap) 4 15.9 mm (0.625) Nylon Standoffs (11.65mm Gap) KIT NUMBER TX BOARD TX PART NUMBER RX BOARD RX PART NUMBER RX OPTION DC2554A-A-KIT DC2556A LTC4125 DC2555A-A LT3652HV Fixed 4.2V Float Voltage DC2554A-B-KIT DC2556A LTC4125 DC2555A-B LT3652HV Fixed 3.6V Float Voltage PERFORMANCE SUMMARY SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V DC2556A Voltage Input I 2.5A 4.5 5.5 V IN VIN I DC2556A V Current V = 5V 2.5 A IN IN IN V DC2555A-A Battery Charge Voltage 4.12 4.2 4.28 V BAT V DC2555A-B Battery Charge Voltage 3.53 3.6 3.67 V BAT I DC2555A-A/ DC2555A-B Charge Current V = 3V 650 mA BAT FB AIR-GAP Separation Between L and L 3.0 5.25 12 mm TX RX BOARD PHOTO Figure1. DC2556A Picture Figure2. DC2555A-A/DC2555A-B Picture Rev. 0 1DEMO MANUAL DC2554A-A-KIT/DC2554A-B-KIT QUICK START PROCEDURE Refer to Figure 3 to 5 for the proper measurement equipment 5. Set PS1 = 3.7V for DC2555A-A (set PS1= 3.2V for setup, DC2555A (for both -A and -B) mounting on DC2556A, DC2555A-B), PS2 = 5V and enable both power supplies and follow the procedure below: simultaneously. The DC2556A should start sweeping the LTx current, looking for a receiver. When a valid 1. Place the DC2555A board atop the DC2556A board receiver is found, the LED sweeping will freeze until by alignging the mounting standoffs (Figure3). This the next search period. This is also indicated by the should result in the transmit coil being direcly above the DC2556A green status LED being turned on. The input receive coil, with the centers aligned. The DC2554A-A- current monitor LED string will show the input current KIT/DC2554A-B-KIT ships with two additional standoff percentage with respect to 2.5A current limit. sizes. This allows the air gap to be varied from 5.25mm to 11.65mm. 6. The DC2555A green LED string should be turned on, indicating power is delivered to the load. If all the green 2. Connect a voltage source PS1 and a 3 resistor LEDs are lit, the LT3652HV on the DC2555A is deliver- RBAT1 in parallel between the BAT and GND turrets ing full programmed battery charge current, which is of DC2555A (Figure4). PS1 and RBAT1 make up the 650mA in this demo. battery emulator. Typical power supplies cannot sink current. By adding a resistor across the power supply 7. The LTC4125 on the DC2556A keeps the transmit inputs that draws more current than the maximum bat- power required by the receiver for about 5 seconds. tery charging current, the power supply only sources Then, the LTC4125 enters another search cycle to current even when the battery charge current is at its check the receiver side power demand. maximum value. 8. When the system is operating correctly, slide a piece of 3. If an ammeter is used to measure the charge current, blank PCB*, or coin between the transmit and receive coil. please be sure to use the external sensing by selecting The transmit current should immediately drop to 0A. EXTS jumper and connecting a pair of cable from VSNS 9. When test is done, turn off PS1 and PS2 simultaneously. and GND turrets to PS1 as Kelvin sensing connection. 2 2 *Testing with a blank PCB of at least 10 cm (1.5 IN ) of copper. If an ammeter is not needed, INTS can be selected and Kelvin sensing connection is not needed. 4. Connect a power supply (PS2) between DC2556A VIN GND turrets. DC2556A can also be powered through Micro-USB cable to a 2.5A, 5V power source. Figure3. DC2555A-A-KIT in Operation Rev. 0 2