TLE6711 Datasheet, PDF (20/28 Pages) Infineon Technologies AG – Multifunctional Voltage Regulator and Watchdog

TLE 6711
Circuit Description
BUC
Pin 6
V_CC
Pin 7
R_Prot1
200 Ω
V_CC
R_VCC1
22kΩ
Error
AMP
R_VCC2
28kΩ
= V_REF
2.8 V
GND GND
V_CC
R_VCC3
39.7k Ω
R _VCC4
10.3kΩ
OV
COMP _{H when}
+
OV at V_CC
-
= V_thOV
1.2 V
GND GND
UV
H when ^COMP
UV at V_Boost
=
V_thUV
4V
L when
OC
COMP
GND Overcurrent
V_thOC
18 mV
L when
Overcurrent
Error-
Signal
PWM
COMP
H when
Error-Signal
<
Error-Ramp
Error-
Ramp
L when
T_j > 175 ˚C
Output Stage
OFF when H
NOR 1
1
Error-FF
R& _Q
OFF when H
PWM-FF
R& _Q
H = ^INV
OFF 1
NAND 2
&
&
Q
S
Boost
Driver
Supply
H=
ON
Gate
Driver
V_Boost
Pin 9
R_Sense
18 mΩ
BDS
Pin 10
Power
D-MOS
BUO
Pin 8
R
Pin 1
Oscillator
V_max
V_min
t_r t_f t_{r t}
Schmitt-trigger 1
&
V_high
Q
S
Ramp ^Vlow _{tr tf tr t} Clock
AEB02947
Figure 8 Buck Converter Block Diagram
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.
Data Sheet V 2.22
20
2001-04-23