User guide

UM10533 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
User manual Rev. 1 — 21 May 2012 11 of 23
NXP Semiconductors
UM10533
TEA1723BT GreenChip SP SMPS demo board
5.7 Conducted EMI measurement results
The EMI is measured with the secondary GND connected to the protected mains earth
GND. Y-capacitor (C10 = 2.2 nF; 2 kV) is added and only one input coil L1 = 1.5 mH is
used. EMI is measured on the neutral phase and on the line phase at V
mains
= 230 V and
at full load. The frequency range is 150 kHz to 30 MHz.
Remark: Improved transformer design will enhance TEA1723BT EMI performance
significantly.
(1) CH1 = V
DRAIN
.
(2) CH4 = V
O
on board. Scale = 100 mV/division.
Fig 9. Output voltage ripple