HI Bill Jhon,
I am doing efficiency study on receiver. planning to have power management on Rx side by introducing a highly efficient buck boost converter after the rectified terminal. Is that i have to retain the same values of Cs, Cd and cb in order to have interoperability with transmitter i.e BQ500110EVM-688 Rev E1. Does having modified RX architecture can we boost the output power efficiency or efficient charging?
Regards,
Vyjaynathi A S
The RX will use and LDO to regulate rectified input voltage to 5V output voltage. The rectified input voltage is the unregulated but filtered DC voltage from the RX coil / Cs caps / rectifying diodes and filter capacitors. Rectified input voltage is set to a target voltage dependent on the output current. See figure 6 in bq51013 data sheet, also see page 4 Vrect-reg. At load greater than 400mA the target voltage is 5.11V. With a V-out of 5V, this would put LDO efficiency at about 97.8%.
The advantage of the buck converter would be an increase in efficiency, but if only the LDO is replaced total system efficiency will not be improved.
Best Regards,
Bill Johns, Applications Engineer
bqTESLA Wireless Power Products
Texas Instruments Inc
Dallas, Texas