Datasheet

+
1
RC
TPS40210/11
150 mV
S Q
QR
+
+
8
5
VDD
GND
R
RC
C
RC
CLK
Frequency > Controller
Frequency
V
IN
Amplitude >
20
V
IN
Duty Cycle < 50%
UDG-08064
10
1
6
TPS40210/11
VDD
RC
GND
C
T
R
T
UDG-07119
10
8
7
VDD
ISNS
GDRV
GND
TPS40210/11
L
V
OUT
V
IN
6
R
ISNS
UDG-07120
C
IFLT
R
IFLT
TPS40210, TPS40211
SLUS772E –MARCH 2008– REVISED OCTOBER 2011 www.ti.com
Figure 21. Diode Connected Synchronization
Current Sense and Overcurrent
The tps40210 and TPS40211 are current mode controllers and use a resistor in series with the source terminal
power FET to sense current for both the current mode control and overcurrent protection. The device enters a
current limit state if the voltage on the ISNS pin exceeds the current limit threshold voltage V
ISNS(oc)
from the
electrical specifications table. When this happens the controller discharges the SS capacitor through a relatively
high impedance and then attempt to restart. The amount of output current that causes this to happen is
dependent on several variables in the converter.
Figure 22. Oscillator Components Figure 23. Current Sense Components
The load current overcurrent threshold is set by proper choice of R
ISNS
. If the converter is operating in
discontinuous mode the current sense resistor is found in Equation 6.
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Product Folder Link(s): TPS40210 TPS40211