TLE6711_07 Datasheet, PDF (14/25 Pages) Infineon Technologies AG – Multifunctional Voltage Regulator and Watchdog

TLE 6711
Circuit Description
External loop compensation is required for converter stability, and is formed by connecting a compensation
resistor-capacitor series-network (R_BUC, C_BUC) between pin BUC and GND.
In the case of overload or short-circuit at V_CC (the output current exceeds the buck overcurrent threshold I_BUOC)
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_CC input as well as the external load against catastrophic failures, an overvoltage protection
is provided which switches the output transistor off as soon as the voltage at pin V_CC exceeds the internal fixed
overvoltage threshold V_BUOVOFF = typ. 6.0 V.
V_C
and
V_Error
V_CP
V_CV
OCLK
H
L
PWM
H
L
I _BUO
I _BULI
I _DBU
V_BUO
V_BOOST
V_CC5
Error Voltage
t
t
t
t
t
t
Overcurrent Threshold Exceeded
Load-Current Increasing with Time;
Controlled by the Error Amp
Controlled by the
Overcurrent Comp
AED02673
Figure 11 Most Important Waveforms of the Buck Converter Circuit
Data Sheet
14
Rev. 3.4, 2007-08-16