AN1299 Datasheet, PDF (1/30 Pages) STMicroelectronics – L638xE tricks and tips

AN1299
Application note
L638xE tricks and tips
Introduction
The ST L638xE family includes five control ICs: L6384E, L6385E, L6386E, L6387E and
L6388E.
They are designed in BCD offline technology and are able to operate at voltage up to 600 V.
The logic inputs are CMOS logic compatible and the driving stages can source up to
400 mA and sink 650 mA.
The bootstrap diode is integrated inside the ICs which helps to reduce the number of PCB
parts and to increase the layout flexibility.
Topics covered:
■ Device family
■ Internal diode structure
■ How to select C_boot
■ Parasitic elements in the half-bridge topology
■ How to manage below-ground voltage on the OUT pin:
– OUT pin voltage that persists below the signal ground
– Undershoot spike on the OUT pin
– Tricks and layout suggestions
■ L6386E: how to deal with signal ground and power ground
August 2008
Rev 3
1/30
www.st.com