AN1344 STMicroelectronics, AN1344 Datasheet
AN1344
Related parts for AN1344
AN1344 Summary of contents
Page 1
... This document will cover the implementation and results for achieving 18V at 6A power supply that will run from both European and domestic mains. (90-132 Vac and 180- 264 Vac, 47-63 Hz). Figure 1: Board layout January 2001 AN1344 - APPLICATION NOTE VIPower: John S. Lo Giudice ...
Page 2
... Load Regulation (0.6 to 6A) from set point Line Regulation (At max load) Efficiency Output Ripple Voltage Input Power at No Load Transient Response, 50% load step EMI AN1344 - APPLICATION NOTE Results 90-132Vac with jumper in, 180 - 264 Vac no jumper 18 V from +/- 0.6% +/- 0.05% 86% @120Vdc and 87% @ 375Vdc 15 mV Max 1 ...
Page 3
... AN1344 - APPLICATION NOTE Figure 2: Electrical schematic BR1 F2 4 FUSE 2.5A 5X20mm .1uF C17 3 X CAP .1uF X CAP CON Thermistor 2 X 6mH 3. TRANSFORMER SPECIFICATION Primary inductance Primary leakage inductance Core Inductance rating (Al Factor) Note 3.1 TRANSFORMER CONSTRUCTION The transformer is wound with a split primary to reduce leakage inductance and minimize the snubbing needed ...
Page 4
... The current shows the power supply being in the continuous conduction mode with a peak of 2A. The snubber R3-C4 reduces the ringing thus lowering the maximum peak voltage on the MOSFET and reducing the EMI. In these waveforms the transil, D3, was replaced AN1344 - APPLICATION NOTE 4/10 ...
Page 5
... AN1344 - APPLICATION NOTE clamp, (R2=39K, 2W and C3=4700pF). The clamp circuit worked the same under normal operation, but during start up or during short circuit operation, the voltage on the drain of VIPer100A reached as high as 750V. The device is avalanche rugged and was able to withstand the momentary energy. Using the Transil at this power level is preferred to reduce the stresses ...
Page 6
... When Vdd reaches below the under voltage lock out of 8V, another type of burst mode appears which is controlled by the Vdd voltage. This is called the Bad burst mode (see figure 6). Bad because it has drawbacks, but the output voltage is still under control. AN1344 - APPLICATION NOTE 6/10 ...
Page 7
... AN1344 - APPLICATION NOTE Figure 6: Bad Burst Mode At Lighter load, the Vdd voltage droops below the under voltage threshold, the start up circuit is reset, and the Vdd capacitor charges back up to the high threshold of 11V through the start up current source. As shown in the picture the reoccurrence of this cycle is about 300ms. The worse output voltage swing is 2 ...
Page 8
... The VIPer100A also has thermal shutdown with hysteresis that is located close to the MOSFET portion of the die, which will protect it from exceeding the temperature limit of the I.C. Figure 7: Output voltage versus the output current Figure 9: Output Ripple AN1344 - APPLICATION NOTE Figure 8: Transient Response 50% Step Change Figure 10: EMI Measurement 8/10 ...
Page 9
... AN1344 - APPLICATION NOTE 8. TRANSIENT RESPONSE 50% STEP CHANGE The output current is modulated from 3A to 6A, 50% duty cycle at a line input of 115Vac. The result is 322mV or 1.8% dynamic regulation with a settling time of 500 microseconds 9. OUTPUT RIPPLE The ripple was measured using a HP probe socket attached after the output connector. This minimizes stray noise being picked up by the scope probe ground lead, which shows up as high frequency noise ...
Page 10
... AN1344 - APPLICATION NOTE Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may results from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice ...