Data Sheet

14

Rev. 3.4, 2007-08-16

TLE 6711

Circuit Description

External loop compensation is required for converter stability, and is formed by connecting a compensation

resistor-capacitor series-network (

R

In the case of overload or short-circuit at

V

the DMOS output transistor is switched off by the overcurrent comparator immediately. The pulse width is then

controlled by the overcurrent comparator as seen before in the boost description.

In order to protect the

V

is provided which switches the output transistor off as soon as the voltage at pin

V

overvoltage threshold

V

Figure 11

Most Important Waveforms of the Buck Converter Circuit

AED02673

t

C

V

Error

V

and

V

CV

CP

V

t

L

H

OCLK

PWM

L

H

t

t

I

BUO

BULI

I

DBU

I

t

BUO

V

t

BOOST

V

CC5

V

Overcurrent Threshold Exceeded

Controlled by the

Load-Current Increasing with Time;

Error Voltage

Overcurrent Comp

Controlled by the Error Amp