Chapter 3- Circuit Theory; Block Diagram; Electronic Circuit Theory - Dell E190Sf Service Manual

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Table Of Contents

Table of Contents

Block Diagram

This Block is comprised of interface board and switching power supplier board which is included by

inverter for CCFL

Electronic Circuit Theory

2.1 Inverter PWM circuit

2.1.1 Inverter Control circuit operations:(fig.2)

DC_5V through R1 and C1 will provide power for U1 on the pin2(VDDA),When the voltage at VDDA

is less than ~3.4V,the IC will enter the lockout mode. The IC will resume operation when the voltage at pin

VDDA exceeds an approximate 3.8V threshold.

Pin3(SEL) used to select appropriate drive topologies,connecting pin SEL to GED shows the IC in the